PROBES FOR IMAGING HUNTINGTIN PROTEIN
20170283439 · 2017-10-05
Assignee
Inventors
- Celia Dominguez (Los Angeles, CA)
- John Wityak (Carlsbad, CA)
- Jonathan Bard (New York, NY)
- Alex KISELYOV (New York, NY, US)
- Christopher John Brown (Abingdon, GB)
- Michael Edward Prime (Swindon, GB)
- Peter David Johnson (Abingdon, GB)
- Daniel Clark-Frew (Wantage, GB)
Cpc classification
A61K51/0455
HUMAN NECESSITIES
A61K51/0459
HUMAN NECESSITIES
C07D519/00
CHEMISTRY; METALLURGY
International classification
C07D519/00
CHEMISTRY; METALLURGY
Abstract
Provided are imaging agents comprising a compound of Formula I, or a pharmaceutically acceptable salt thereof, and methods of their use.
##STR00001##
Claims
1. An imaging agent comprising a compound of Formula I, ##STR00156## or a pharmaceutically acceptable salt thereof, wherein L.sub.1 is —CH═CH— or L.sub.1 is absent; R.sub.1 is chosen from phenyl or heteroaryl, each of which is optionally substituted with one, two, or three groups independently chosen from cyano, halo, heteroaryl, lower alkyl, lower alkyl substituted with one or two substituents independently chosen from lower alkoxy substituted with heteroaryl, —C(O)O-lower alkyl, hydroxyl, lower alkynyloxy, lower alkoxy, and lower alkoxy substituted with one or two substituents independently chosen from halo, heterocycloalkyl, heteroaryl, heteroaryl substituted with lower alkoxy, optionally substituted amino, alkyl substituted with heteroaryl, and alkyl substituted with heteroaryl substituted with lower alkoxy; or R.sub.1 is phenyl substituted with two groups, which taken together with the carbon atoms, to which they are bonded form a heterocycloalkenyl ring wherein said phenyl is further optionally substituted with a substituent chosen from halo, heteroaryl, and optionally substituted amino; L.sub.2 is —N(R.sub.4)— or L.sub.2 is absent; R.sub.2 is chosen from hydrogen, lower alkyl, and lower alkyl substituted with lower alkoxy, amino, (alkyl)amino, (dialkyl)amino, or hydroxy; for each occurrence, R.sub.3 is independently chosen from halo, cyano, lower alkoxy, lower alkyl optionally substituted with amino, (alkyl)amino, or di(alkyl)amino, and ethynyl optionally substituted with tri(alkyl)silyl; R.sub.4 is chosen from hydrogen and lower alkyl; and m is 0, 1, or 2, wherein the compound of Formula I, or a pharmaceutically acceptable salt thereof, is labeled with one or more positron-emitting radionuclides.
2. The imaging agent of claim 1, wherein L.sub.1 is absent.
3. The imaging agent of claim 1, wherein L.sub.1 is —CH═CH—.
4. The imaging agent of claim 1, wherein R.sub.1 is ##STR00157## wherein Y is chosen from O, NR.sub.7, and S; R.sub.7 is chosen from hydrogen and lower alkyl; Z is chosen from CH and N; for each occurrence, R.sub.6 is chosen from halo, hydroxyl, lower alkoxy, and lower alkoxy substituted with halo, heteroaryl, or optionally substituted amino; and p is chosen from 0, 1 and 2.
5. The imaging agent of claim 4, wherein Y is NR.sub.7 and Z is N.
6. The imaging agent of claim 4, wherein R.sub.7 is chosen from hydrogen and methyl.
7. The imaging agent of claim 4, wherein Y is O and Z is CH.
8. The imaging agent of claim 4, wherein Y is S and Z is N.
9. The imaging agent of claim 4, wherein Y is O and Z is N.
10. The imaging agent of claim 4, wherein p is 1.
11. The imaging agent of claim 10, wherein R.sub.6 is chosen from bromo, fluoro, methoxy, hydroxyl, 2-fluoroethyoxy, pyridine-3-ylmethoxy, aminomethoxy, (methylamino)ethoxy, and (dimethylamino)ethoxy.
12. The imaging agent of claim 4, wherein p is 0.
13. The imaging agent of claim 1, wherein R.sub.1 is heteroaryl substituted with (5-methoxypyrazin-2-yl)methoxy, 5-methoxypyrazin-2-yl)methoxy, 5-(tert-butoxycarbonyl) or (5-methoxypyridin-2-yl)methoxy.
14. The imaging agent of claim 1, wherein R.sub.1 is chosen from 5-fluoro-1-benzofuran-2-yl, 5-methoxy-1-benzofuran-2-yl, 5-hydroxy-1-benzofuran-2-yl, 5-(2-fluoroethxoy)-1-benzofuran-2-yl, 6-methoxy-1-benzofuran-2-yl, 5-bromo-1-benzofuran-2-yl, 5-methoxy-1-methyl-1H-1,3-benzodiazol-2-yl, 5-methoxy-1H-1,3-benzodiazol-2-yl, 6-methoxy-1-methyl-1H-1,3-benzodiazol-2-yl, 5-(pyridine-3-yl)methoxy-1-benzofuran-2-yl, 6-methoxy-1,3-benzothiazole-2-yl, 5-methoxy-1,3-benzoxazol-2-yl, 5-[2-(dimethylamino)ethoxy]-1-benzofuran-2-yl, and 5-[(5-methoxypyridin-2-yl)methoxy]pyrazine-2-yl.
15. The imaging agent of claim 1, wherein R.sub.1 is chosen from phenyl optionally substituted with one, two, or three groups independently chosen from cyano, halo, heterocycloalkyl, heteroaryl, lower alkyl, lower alkyl substituted with one or two substituents independently chosen from lower alkoxy substituted with heteroaryl, —C(O)O-lower alkyl, hydroxyl, lower alkynyloxy, lower alkoxy, and lower alkoxy substituted with one or two substituents independently chosen from halo, heteroaryl, heteroaryl substituted with lower alkoxy, optionally substituted amino, alkyl substituted with heteroaryl, and alkyl substituted with heteroaryl substituted with lower alkoxy.
16. The imaging agent of claim 15, wherein R.sub.1 is phenyl optionally substituted with one, two, or three groups independently chosen from methoxy, pyridine-3-ylmethoxy, pyrazin-2-yl, cyano, (5-methoxypyrazin-2-yl)methoxy, (prop-2-yn-1-yloxy), 5H, 6H-imdazo[2,1-b][1,3]thiazol-3-ylmethoxy, and [(5-methoxypyridin-2-yl)methyl]amino.
17. The imaging agent of claim 16, wherein R.sub.1 is 4-methoxyphenyl, 3-(pyridine-3-ylmethoxy)phenyl, 4-(pyridine-3-ylmethoxy)phenyl, 3-(pyrazin-2-yl)phenyl, 4-(pyrazin-2-yl)phenyl, 4-cyanophenyl, 4-[(5-methoxypyrazin-2-yl)methoxy]phenyl, and 4-(prop-2-yn-1-yloxy)phenyl.
18. The imaging agent of claim 1, wherein R.sub.1 is chosen from 5-(tert-butoxycarbonyl)-4,5,6,7-tetrahydrofuro[3,2-c]pyridin-2-yl, 2,3-dihydro-1,4-benzodioxin-6-yl, 5-bromofuran-2-yl, 1-benzofuran-5-yl, 11-methoxy-7-thia-2,5-diazatricyclo[6.4.0.0.sup.2,6]dodeca-1(12),3,5,8,10-pentaen-4-yl, and 10-methoxy-7-thia-2,5-diazatricyclo[6.4.0.0.sup.2,6]dodeca-1(12),3,5,8,10-pentaen-4-yl.
19. The imaging agent of claim 1, wherein L.sub.2 is absent.
20. The imaging agent of claim 19, wherein R.sub.2 is hydrogen.
21. The imaging agent of claim 19, wherein R.sub.2 is lower alkyl or lower alkyl substituted with lower alkoxy, amino, (alkyl)amino or (dialkyl)amino.
22. The imaging agent of claim 1, wherein L.sub.2 is —N(R.sub.4)—.
23. The imaging agent of claim 22, wherein R.sub.4 is hydrogen or methyl.
24. The imaging agent of claim 22, wherein R.sub.2 is chosen from hydrogen, lower alkyl and lower alkyl substituted with hydroxy, lower alkoxy, amino, (alkyl)amino or (dialkyl)amino.
25. The imaging agent of claim 24, wherein R.sub.2 is chosen from hydrogen, methyl, 2-methoxyethyl, 2-hydroxyethyl, and 2-(dimethylamino)ethyl.
26. The imaging agent of claim 1, wherein m is 1.
27. The imaging agent of claim 26, wherein R.sub.3 is chosen from bromo, chloro, fluoro, aminomethyl, 2-(trimethylsilyl)ethynyl, ethynyl, methoxy, and cyano.
28. The imaging agent of claim 27, wherein R.sub.3 is chosen from bromo, chloro, fluoro, methoxy, and cyano.
29. The imaging agent of claim 28, wherein R.sub.3 is cyano.
30. The imaging agent of claim 1, wherein m is 0.
31. A imaging agent of claim 1, or a pharmaceutically acceptable salt thereof, wherein the compound is chosen from 2-(5-fluoro-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine; 2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine; 6-fluoro-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine; 7-fluoro-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine; 2-(5-methoxy-1-benzofuran-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-[6-fluoro-3-(methylamino)imidazo[1,2-a]pyridin-2-yl]-1-benzofuran-5-ol; 2-(5-methoxy-1-benzofuran-2-yl)-N-(2-methoxyethyl)imidazo[1,2-a]pyridin-3-amine; 2-[7-fluoro-3-(methylamino)imidazo[1,2-a]pyridin-2-yl]-1-benzofuran-5-ol; 2-{3-[(2-hydroxyethyl)amino]imidazo[1,2-a]pyridin-2-yl}-1-benzofuran-5-ol; 2-(5-hydroxy-1-benzofuran-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-[5-(2-fluoroethoxy)-1-benzofuran-2-yl]-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(4-methoxyphenyl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(6-methoxy-1-benzofuran-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 7-methoxy-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine; 3-(methylamino)-2-[3-(pyridin-3-ylmethoxy)phenyl]imidazo[1,2-a]pyridine-7-carbonitrile; 3-(methylamino)-2-[4-(pyridin-3-ylmethoxy)phenyl]imidazo[1,2-a]pyridine-7-carbonitrile; 7-chloro-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine; 7-bromo-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine; 2-(5-methoxy-1-benzofuran-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-6-carbonitrile; 2-(5-bromo-1-benzofuran-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 3-(methylamino)-2-[3-(pyrazin-2-yl)phenyl]imidazo[1,2-a]pyridine-7-carbonitrile; 3-(methylamino)-2-[4-(pyrazin-2-yl)phenyl]imidazo[1,2-a]pyridine-7-carbonitrile; 2-[(E)-2-(4-methoxyphenyl)ethenyl]-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(5-methoxy-1-benzofuran-2-yl)-3-[(2-methoxyethyl)amino]imidazo[1,2-a]pyridine-7-carbonitrile; 2-(2, 3-dihydro-1,4-benzodioxin-6-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(5-bromofuran-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(4-cyanophenyl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(1-benzofuran-5-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 3-(methylamino)-2-[4-(prop-2-yn-1-yloxy)phenyl]imidazo[1,2-a]pyridine-7-carbonitrile; 2-(5-fluoro-1-benzofuran-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-{3-[(5-methoxypyrazin-2-yl)methoxy]phenyl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-{5-[(5-methoxypyrazin-2-yl)methoxy]pyridin-2-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 3-(dimethylamino)-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(5-methoxy-1-methyl-1H-1,3-benzodiazol-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(6-methoxy-1,3-benzothiazol-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(5-methoxy-1,3-benzoxazol-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(5-methoxy-1H-1,3-benzodiazol-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(6-methoxy-1-methyl-1H-1,3-benzodiazol-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 3-(methylamino)-2-[5-(pyridin-3-ylmethoxy)-1-benzofuran-2-yl]imidazo[1,2-a]pyridine-7-carbonitrile; 3-amino-2-[5-(2-fluoroethoxy)-1-benzofuran-2-yl]imidazo[1,2-a]pyridine-7-carbonitrile; 3-amino-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(5-methoxy-1-benzofuran-2-yl)-3-(methoxymethyl)imidazo[1,2-a]pyridine-7-carbonitrile; 3-[(dimethylamino)methyl]-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile; 2-{5-[2-(dimethylamino)ethoxy]-1-benzofuran-2-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 3-(methylamino)-2-{4-[(pyridin-3-ylmethoxy)methyl]phenyl}imidazo[1,2-a]pyridine-7-carbonitrile; 3-{[2-(dimethylamino)ethyl]amino}-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile tert-butyl 2-[7-cyano-3-(methylamino)imidazo[1,2-a]pyridin-2-yl]-4H,5H,6H,7H-furo[3,2-c]pyridine-5-carboxylate; 7-(aminomethyl)-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine; 3-(methylamino)-2-{3-[(pyridin-3-ylmethoxy)methyl]phenyl}imidazo[1,2-a]pyridine-7-carbonitrile; 2-{4-[(5-methoxypyrazin-2-yl)methoxy]phenyl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-{6-[(5-methoxypyrazin-2-yl)methoxy]pyridin-3-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(5-methoxy-1-benzofuran-2-yl)-N-methyl-7-[2-(trimethylsilyl)ethynyl]imidazo[1,2-a]pyridin-3-amine; 7-ethynyl-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine; 2-(4-{[(5-methoxypyridin-2-yl)methyl]amino}phenyl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-(4-{5H,6H-imidazo[2,1-b][1,3]thiazol-3-ylmethoxy}phenyl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-{10-methoxy-7-thia-2,5-diazatricyclo[6.4.0.0.sup.2,6]dodeca-1(12),3,5,8,10-pentaen-4-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; 2-{11-methoxy-7-thia-2, 5-diazatricyclo[6.4.0.0.sup.2,6]dodeca-1(12),3,5,8,10-pentaen-4-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile; and 2-{5-[(5-methoxypyridin-2-yl)methoxy]pyrazin-2-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile.
32. The imaging agent of claim 1, wherein said agent contains one or more positron-emitting radionuclides are selected from: .sup.11C, .sup.13N, .sup.15O, and .sup.18F.
33. A method of generating diagnostic images in an individual comprising administering an effective amount of an imaging agent of claim 1 to an individual, and generating an image of at least a part of said individual.
34. The method of claim 33, wherein generating an image of at least a part of said individual comprises generating an image to detect the presence or absence of huntingtin protein (HTT protein) monomers or aggregates in the brain of said individual; and detecting the presence or absence of a pathologic process.
35. The method of claim 34, wherein said HTT protein monomers or aggregates are present in the basal ganglia of said brain of said individual.
36. The method of claim 34, wherein the pathologic process is a neurodegenerative disease.
37. The method of claim 36, wherein the neurodegenerative disease is chosen from Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease, Parkinson's disease, Prion disease and spinocerebellar ataxias.
38. The method of claim 37, wherein the neurodegenerative disease is Huntington's disease (HD).
39. The method of claim 33, wherein said effective amount of said imaging agent comprises from about 0.1 to about 20 mCi.
40. The method of claim 39, wherein said effective amount of said imaging agent comprises about 10 mCi.
41. The method of claim 33, wherein said generating an image comprises positron emission tomography (PET) imaging, PET with concurrent computed tomography imaging (PET/CT), PET with concurrent magnetic resonance imaging (PET/MRI), or a combination thereof.
42. The method of claim 41, wherein said generating an image comprises PET imaging.
Description
EXAMPLES
General Experimental Details
[0326] Commercially available reagents and solvents (HPLC grade) were used without further purification. .sup.1H NMR spectra were recorded on a Bruker DRX 500 MHz spectrometer or a Bruker DPX 250 MHz spectrometer in deuterated solvents. Chemical shifts (δ) are in parts per million. SCX chromatography was performed with Biotage Isolute Flash SCX-2 loading the sample in methanol and eluting with methanol then 5% ammonia in methanol.
[0327] Analytical HPLC-MS (METCR1278), was performed on Shimadzu LCMS-2010EV systems using reverse phase Atlantis dC18 columns (3 μm, 2.1×50 mm), gradient 5-100% B (A=water/0.1% formic acid, B=acetonitrile/0.1% formic acid) over 3 minutes injection volume 3 μL, flow=1.0 mL/minute. UV spectra were recorded at 215 nm using a SPD-M20A photo diode array detector. Mass spectra were obtained over the range m/z 150 to 850 at a sampling rate of 2 scans per second using a LCMS2010EV. Data were integrated and reported using Shimadzu LCMS-Solutions and PsiPort software.
[0328] Alternatively, (METCR1416) analytical HPLC-MS on Shimadzu LCMS-2010EV systems using reverse phase Water Atlantis dC18 columns (3 μm, 2.1×100 mm), gradient 5-100% B (A=water/0.1% formic acid, B=acetonitrile/0.1% formic acid) over 7 minutes, injection volume 3 μL, flow=0.6 mL/minute. UV spectra were recorded at 215 nm using a SPD-M20A photo diode array detector. Mass spectra were obtained over the range m/z 150 to 850 at a sampling rate of 2 scans per second using a LCMS2010EV. Data were integrated and reported using Shimadzu LCMS-Solutions and PsiPort software.
[0329] Alternatively, (MET-uHPLC-AB-101) analytical HPLC-MS were performed on a Waters Acquity UPLC system with Waters PDA and ELS detectors using a Phenomenex Kinetex-XB C-18 column, (1.7 μM, 2.1 mm×100 mm at a column temperature of 40° C., gradient 5-100% B (A=water/0.1% formic acid; B=acetonitrile/0.1% formic acid) over 5.3 minutes, then 100% B for 0.5 minute, flow=0.6 mL/minute. UV spectra were recorded at 215 nm using a Waters Acquity photo diode array. Mass spectra were obtained over the range m/z 150 to 850 at a sampling rate of 5 scans per second using a Waters SQD. Data were integrated and reported using Waters MassLynx and OpenLynx software.
[0330] All example compounds display an LC purity of >95% unless stated otherwise.
Method 1
Scheme for Method 1
[0331] ##STR00005##
Step 1, Method 1: 2-(5-Fluoro-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine
[0332] To a solution of pyridin-2-amine (0.20 g, 2 mmol) and 5-fluorobenzofuran-2-carboxaldehyde (0.35 g, 2 mmol) in methanol (10 mL) was added methyl isocyanide (0.09 mL, 1.9 mmol), followed by acetic acid (0.5 mL). The reaction was stirred at room temperature for 4 days. 1 M sodium hydroxide (5 mL) was added and the methanol was evaporated. Water (10 mL) was added, the mixture washed with ethyl acetate and acidified with 1 M hydrochloric acid. The precipitate was filtered off, and then washed with water and ethyl acetate to give the title compound 0.26 g (46% yield) as a yellow solid.
Example 1, Method 1: 2-(5-Fluoro-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine
[0333] δ.sub.H NMR (500 MHz, DMSO) 8.28 (d, J=6.85 Hz, 1H), 7.64 (dd, J=4.26, 8.98 Hz, 1H), 7.43-7.53 (m, 2H), 7.18-7.27 (m, 2H), 7.12 (dt, J=2.66, 9.25 Hz, 1H), 6.88-6.97 (m, 1H), 5.06 (q, J=5.48 Hz, 1H), 2.83 (d, J=5.48 Hz, 3H). Tr(METCR1416)=3.08 min (ES.sup.+) (M+H).sup.+ 282.
[0334] The following examples were prepared using Method 1 described above:
TABLE-US-00001 TABLE 1 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 2
Scheme for Method 2
[0335] ##STR00035##
Step 1, Method 2: 2-[δ-Fluoro-3-(methylamino)imidazo[1,2-a]pyridin-2-yl]-1-benzofuran-5-ol
[0336] 6-Fluoro-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine (prepared according to Method 1, 0.25 g, 0.8 mmol) was dissolved in dichloromethane (10 mL). 1 M boron tribromide in dichloromethane (2.4 mL, 2.4 mmol) was added and the reaction stirred at room temperature for 1 hour. The reaction was quenched with methanol and the volatiles evaporated. The residue was dissolved in water and treated with saturated aqueous sodium bicarbonate. The resulting precipitate was filtered and recrystallized from 1:1 ethanol:water to give the title compound 0.08 g (33% yield) as a yellow powder.
Example 1, Method 2: 2-[6-Fluoro-3-(methylamino)imidazo[1,2-a]pyridin-2-yl]-1-benzofuran-5-ol
[0337] δ.sub.H NMR (500 MHz, DMSO) 8.85 (br. s., 1H), 7.81 (d, J=5.83 Hz, 2H), 7.48 (d, J=8.83 Hz, 1H), 7.36 (s, 1H), 7.05 (d, J=2.36 Hz, 1H), 6.84 (dd, J=2.21, 8.83 Hz, 1H), 2.86 (s, 3H). Tr(METCR1416)=2.91 min, (ES.sup.+) (M+H).sup.+ 298.
[0338] The following examples were prepared using Method 2 described above.
TABLE-US-00002 TABLE 2 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 3
Scheme for Method 3
[0339] ##STR00042##
Step 1, Method 3: 5-(2-Fluoroethoxy)-1-benzofuran
[0340] To a stirred solution of 1-benzofuran-5-ol (275 mg, 2.05 mmol) in N,N-dimethylformamide (5 mL) was added 1-bromo-2-fluoroethane (306 μL, 4.10 mmol) and potassium carbonate (567 mg, 4.10 mmol) and the mixture was heated to 60° C. for 18 hours. A further portion of 1-bromo-2-fluoroethane (150 μL, 2.00 mmol) was added and the reaction was stirred at 60° C. for 4 hours. Further potassium carbonate (273 mg, 2.00 mmol) was added and the mixture was stirred at room temperature for 72 hours. Further potassium carbonate (273 mg, 2.00 mmol) was added and the mixture was heated to 80° C. for 5 hours. The mixture was cooled to room temperature and water (10 mL) was added. The mixture was then extracted with ethyl acetate (3×10 mL) and the organic extracts were combined, dried, concentrated and purified by FCC (silica, 10-90% dichloromethane in heptane) to give the title compound 343 mg (93% yield) as a colorless oil. δ.sub.H (500 MHz, DMSO) 7.94 (d, J=2.1 Hz, 1H), 7.49 (d, J=8.9 Hz, 1H), 7.20 (d, J=2.5 Hz, 1H), 6.93 (dd, J=8.9, 2.5 Hz, 1H), 6.88 (s, 1H), 4.86-4.67 (m, 2H), 4.34-4.15 (m, 2H). Tr(METCR1278)=1.87 min, (ES.sup.+) (M+H).sup.+ 181.
Step 2, Method 3: 5-(2-Fluoroethoxy)-1-benzofuran-2-carboxaldehyde
[0341] To a solution of 5-(2-fluoroethoxy)-1-benzofuran (250 mg, 1.39 mmol) in tetrahydrofuran (5 mL) cooled to −78° C. was added drop-wise 1.6 M n-butyllithium in hexanes (1.3 mL, 2.08 mmol). The resulting mixture was stirred for a further 10 minutes before anhydrous N,N-dimethylformamide (0.16 mL, 1.67 mmol) was added drop-wise. The reaction was allowed to warm to room temperature before water (5 mL) was added and the mixture extracted with ethyl acetate (2×10 mL), dried and concentrated. Purification by FCC (silica, 0-50% dichloromethane in heptane) gave the title compound 0.216 g (74% yield) as an orange-yellow solid. δ.sub.HNMR (500 MHz, DMSO) 9.83 (s, 1H), 7.91 (s, 1H), 7.67 (d, J=9.1 Hz, 1H), 7.40 (d, J=2.6 Hz, 1H), 7.23 (dd, J=9.1, 2.7 Hz, 1H), 4.89-4.60 (m, 2H), 4.44-4.07 (m, 2H). Tr(METCR1278)=1.73 min, (ES.sup.+) (M+H).sup.+ 209.
Step 3, Method 3: 2-[5-(2-Fluoroethoxy)-1-benzofuran-2-yl]-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0342] To a solution of 5-(2-fluoroethoxy)-1-benzofuran-2-carbaldehyde (150 mg, 0.72 mmol) and 4-cyano-2-aminopyridine (86 mg, 0.72 mmol) in methanol (5 mL) was added methyl isocyanide (0.03 mL, 0.68 mmol), followed by acetic acid (0.5 mL). The mixture was stirred for 5 days, 1 M hydrochloric acid (5 mL) was added and the methanol carefully removed by rotary evaporation. The resulting mixture was neutralised with aqueous sodium bicarbonate, then extracted with dichloromethane (3×10 mL), dried, filtered and concentrated. Purification by FCC (silica, 2% methanol in dichloromethane) and recrystallisation from acetonitrile containing a minimum of DMSO, gave the title compound 30 mg (10% yield) as bright orange crystals.
Example 1, Method 3: 2-[5-(2-Fluoroethoxy)-1-benzofuran-2-yl]-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0343] δ.sub.H NMR (250 MHz, DMSO) 8.41 (dd, J=0.88, 7.20 Hz, 1H), 8.23 (dd, J=0.93, 1.50 Hz, 1H), 7.56 (d, J=8.93 Hz, 1H), 7.42-7.11 (m, 3H), 6.95 (dd, J=2.61, 8.91 Hz, 1H), 5.46 (q, J=5.40 Hz, 1H), 5.06-4.54 (m, 2H), 4.50-4.08 (m, 2H), 2.88 (d, J=5.44 Hz, 3H). Tr(MET-uHPLC-AB-101)=3.11 min, (ES.sup.+) (M+H).sup.+ 351.
[0344] The following example was prepared using Method 3 described above:
TABLE-US-00003 TABLE 3 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 4
Scheme for Method 4
[0345] ##STR00045##
Step 1, Method 4: 2-(5-Methoxy-1-benzofuran-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0346] 5-Methoxy-1-benzofuran-2-carbaldehyde (300 mg, 1.70 mmol) and 2-aminoisonicotinonitrile (203 mg, 1.70 mmol) were dissolved in methanol (10 mL). Acetic acid (1 mL) and methyl isocyanide (76 μL, 1.70 mmol) were added and the mixture stirred at room temperature. After 3 days the reaction mixture was filtered and the yellow precipitate washed with methanol (3×10 mL) and dried under suction to give the title compound 256 mg (46% yield) as an orange powder. δ.sub.H NMR (500 MHz, DMSO) 8.41 (d, J=7.15 Hz, 1H), 8.22 (br. s, 1H), 7.54 (d, J=8.89 Hz, 1H), 7.25 (s, 1H), 7.20 (d, J=2.56 Hz, 1H), 7.18 (dd, J=1.56, 7.15 Hz, 1H), 6.91 (dd, J=2.61, 8.89 Hz, 1H), 5.43 (q, J=5.44 Hz, 1H), 3.81 (s, 3H), 2.89 (d, J=5.46 Hz, 3H). Tr(METCR1278)=1.94 min, (ES.sup.+) (M+H).sup.+ 319.
Step 2, Method 4: 3-(Dimethylamino)-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile
[0347] 2-(5-Methoxy-1-benzofuran-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile (98%, 30 mg, 0.09 mmol) was dissolved in N,N-dimethylformamide (1 mL) and treated with sodium hydride (60% in mineral oil, 6 mg, 0.14 mmol). The mixture was stirred at room temperature for 10 minutes then treated with methyl iodide (50 μL of a solution comprising 60 μL methyl iodide in 500 μL N,N-dimethylformamide, 0.09 mmol). The mixture was stirred at room temperature for 16 hours, then quenched by the addition of water (2 mL) and extracted with ethyl acetate (2×3 mL). Combined organic extracts were washed with water (1 mL) and brine (1 mL), then dried, filtered and concentrated. Purification by preparative HPLC (acetonitrile-water-0.1% formic acid) gave the title compound 8 mg (25% yield) as an orange powder.
Example 1, Method 4: 3-(Dimethylamino)-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile
[0348] δ.sub.H NMR (500 MHz, DMSO) 8.44 (dd, J=0.73, 7.10 Hz, 1H), 8.29 (s, 1H), 7.59 (d, J=8.90 Hz, 1H), 7.29 (d, J=0.59 Hz, 1H), 7.26-7.22 (m, 2H), 6.94 (dd, J=2.62, 8.91 Hz, 1H), 3.81 (s, 3H), 2.94 (s, 6H). Tr(MET-uHPLC-AB-101)=3.63 min, (ES.sup.+) (M+H).sup.+ 333.
[0349] The following example was prepared using Method 4 described above:
TABLE-US-00004 TABLE 4 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 5
Scheme for Method 5
[0350] ##STR00047##
Step 1, Method 5: 1-(5-Methoxy-1-benzofuran-2-yl)ethan-1-one
[0351] 2-Hydroxy-5-methoxybenzaldehyde (8.26 mL, 65.7 mmol) was added drop-wise to a suspension of potassium carbonate (10.9 g, 78.9 mmol) in acetone (200 mL). 1-Chloropropan-2-one (6.03 mL, 75.6 mmol) was added drop-wise over 5 minutes and the mixture heated to reflux for 3 hours. The reaction mixture was cooled to room temperature and filtered. The filter cake was washed with additional acetone (2×30 mL) and the filtrate concentrated. Purification by FCC (silica, 25-50% ethyl acetate in heptane) gave the title compound 11.6 g (90% yield) as a yellow powder. δ.sub.H NMR (500 MHz, DMSO) 7.78 (d, J=0.71 Hz, 1H), 7.61 (d, J=9.07 Hz, 1H), 7.28 (d, J=2.61 Hz, 1H), 7.13 (dd, J=2.66, 9.06 Hz, 1H), 3.81 (s, 3H), 2.54 (s, 3H). Tr(METCR1278)=1.75 min, (ES.sup.+) (M+H).sup.+ 191.
Step 2, Method 5: 2-Bromo-1-(5-methoxy-1-benzofuran-2-yl)ethan-1-one
[0352] 1-(5-Methoxy-1-benzofuran-2-yl)ethan-1-one (50 mg, 0.25 mmol) was dissolved in tetrahydrofuran (2 mL) and cooled to 0° C. N,N,N-trimethylanilinium tribromide (95 mg, 0.25 mmol) was added portion-wise over 2 minutes and the mixture stirred for 1 hour, warming slowly to room temperature. The reaction was quenched by the addition of saturated aqueous sodium bicarbonate (5 mL). The mixture was extracted with methyl tert-butyl ether (10 mL). The organic layer was separated and washed with brine (10 mL), then dried, filtered and concentrated to give the title compound 52 mg (62% yield) as a yellow gum. δ.sub.H NMR (500 MHz, DMSO) 8.03-7.93 (m, 1H), 7.65 (d, J=9.09 Hz, 1H), 7.33 (d, J=2.60 Hz, 1H), 7.18 (dd, J=2.66, 9.08 Hz, 1H), 4.80 (s, 2H), 3.82 (s, 3H). Tr(METCR1278)=1.92 min, (ES.sup.+) (M+H).sup.+ 269/271, 81%.
Step 3, Method 5: 2-(5-Methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile
[0353] 2-Bromo-1-(5-methoxy-1-benzofuran-2-yl)ethan-1-one (48 mg, 0.18 mmol) and 2-aminoisonicotinonitrile (21 mg, 0.18 mmol) were dissolved in acetone (5 mL) and stirred at room temperature for 16 hours. The reaction mixture was concentrated and the residue suspended in saturated aqueous sodium bicarbonate. The precipitate was collected by filtration and dried under suction. The crude product was triturated in 2:1 acetonitrile:DMSO (1 mL) and collected by filtration. The solid was washed with water (1 mL) and dried under suction to give the title compound 6 mg (12% yield) as an off-white powder.
Example 1, Method 5: 2-(5-Methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile
[0354] δ.sub.H NMR (500 MHz, DMSO) 8.74 (d, J=6.96 Hz, 1H), 8.61 (s, 1H), 8.38 (s, 1H), 7.55 (d, J=8.88 Hz, 1H), 7.34 (s, 1H), 7.27 (d, J=7.00 Hz, 1H), 7.22 (d, J=2.38 Hz, 1H), 6.94 (dd, J=2.48, 8.92 Hz, 1H), 3.81 (s, 3H). Tr(MET-uHPLC-AB-101)=3.06 min, (ES.sup.+) (M+H).sup.+ 290.
[0355] The following example was prepared using Method 5 described above:
TABLE-US-00005 TABLE 5 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 6
Scheme for Method 6
[0356] ##STR00049##
Step 1, Method 6: 5-Methoxy-1,2-dimethyl-1H-1,3-benzodiazole and δ-methoxy-1,2-dimethyl-1H-1,3-benzodiazole
[0357] 5-Methoxy-2-methyl-1H-1,3-benzodiazole (500 mg, 3.08 mmol) was dissolved in anhydrous N,N-dimethylformamide (10 mL) and cooled to 0° C. The solution was treated with sodium hydride (60% in mineral oil, 185 mg, 4.62 mmol) and stirred at 0° C. for 20 minutes. Methyl iodide (191 μL, 3.08 mmol) was added, and the mixture was stirred at room temperature for 1 hour. The reaction mixture was quenched by the addition of water (10 mL) and extracted with ethyl acetate (2×15 mL). Combined organic extracts were washed with water (2×10 mL) and brine (2×10 mL), dried, filtered and concentrated. Purification by FCC (silica, 12-100% ethyl acetate in heptane then 10% methanol in dichloromethane) gave a 1:1 mixture of the title compounds 212 mg (40% yield) as a brown powder. δ.sub.H NMR (500 MHz, chloroform) 7.55 (d, J=8.72 Hz, 1H), 7.19 (d, J=2.33 Hz, 1H), 7.15 (d, J=8.73 Hz, 1H), 6.89 (dd, J=2.37, 8.73 Hz, 1H), 6.86 (dd, J=2.39, 8.72 Hz, 1H), 6.75 (d, J=2.33 Hz, 1H), 3.87 (s, 3H), 3.85 (s, 3H), 3.69 (s, 3H), 3.67 (s, 3H), 2.58 (s, 3H), 2.57 (s, 3H). Tr(METCR1278)=0.77 min, (ES.sup.+) (M+H).sup.+ 177.
Step 2, Method 6: 5-Methoxy-1-methyl-1H-1,3-benzodiazole-2-carbaldehyde and 6-methoxy-1-methyl-1H-1,3-benzodiazole-2-carbaldehyde
[0358] A 1:1 mixture of 5-methoxy-1,2-dimethyl-1H-1,3-benzodiazole and 6-methoxy-1,2-dimethyl-1H-1,3-benzodiazole (212 mg, 1.20 mmol) and selenium dioxide (167 mg, 1.50 mmol) were suspended in dioxane (10 mL) in a sealed tube and heated to 110° C. for 3 hours. The reaction mixture was filtered through celite, eluting with dioxane until the filtrate ran colourless. The filtrate was concentrated to give a 1:1 mixture of the title compounds (186 mg, 81% yield) as a brown powder. δ.sub.H NMR (500 MHz, DMSO) 9.98 (s, 1H), 9.92 (s, 1H), 7.74 (d, J=8.97 Hz, 1H), 7.67 (d, J=9.02 Hz, 1H), 7.32 (d, J=2.34 Hz, 1H), 7.24 (d, J=2.35 Hz, 1H), 7.15 (dd, J=2.40, 9.02 Hz, 1H), 7.01 (dd, J=2.41, 8.97 Hz, 1H), 4.08 (s, 6H), 3.88 (s, 3H), 3.83 (s, 3H). Tr(METCR1278)=1.00 min, (ES.sup.+) (M+H.sub.3O).sup.+ 209.
Step 3, Method 6: 2-(6-Methoxy-1-methyl-1H-1,3-benzodiazol-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0359] A 1:1 mixture of 5-methoxy-1-methyl-1H-1,3-benzodiazole-2-carbaldehyde and δ-methoxy-1-methyl-1H-1,3-benzodiazole-2-carbaldehyde (186 mg, 0.98 mmol), 2-aminoisonicotinonitrile (116 mg, 0.98 mmol) and scandium triflate (24 mg, 0.05 mmol) were dissolved in trifluoroethanol (3 mL). Methyl isocyanide (44 μL, 0.98 mmol) was added and the mixture heated to 160° C. under microwave irradiation for 10 minutes. The reaction mixture was quenched with 1 M hydrochloric acid (2 mL) and concentrated. The residual aqueous suspension was neutralised with saturated aqueous sodium bicarbonate (until effervescence ceased) and extracted with ethyl acetate (2×10 mL). Combined organic extracts were washed with brine (10 mL), dried, filtered and concentrated. FCC (silica, 12-100% ethyl acetate in cyclohexane) gave a mixture of two regioisomers. Purification by preparative HPLC (acetonitrile-water-0.1% formic acid) gave the title compound 16 mg (25% yield) as an orange powder.
Example 1, Method 6: 2-(6-Methoxy-1-methyl-1H-1,3-benzodiazol-2-yl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0360] δ.sub.H NMR (500 MHz, DMSO) 8.47 (d, J=7.23 Hz, 1H), 8.28 (s, 1H), 7.58 (d, J=8.74 Hz, 1H), 7.18 (d, J=2.29 Hz, 1H), 7.15 (dd, J=1.57, 7.21 Hz, 1H), 6.88 (dd, J=2.37, 8.74 Hz, 1H), 6.74 (d, J=5.77 Hz, 1H), 4.26 (s, 3H), 3.86 (s, 3H), 2.98 (d, J=5.79 Hz, 3H). Tr(MET-uHPLC-AB-101)=2.05 min, (ES.sup.+) (M+H).sup.+ 333.
[0361] The following example was prepared using Method 6 described above:
TABLE-US-00006 TABLE 6 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 7
Scheme for Method 7
[0362] ##STR00052##
Step 1, Method 7: 3-[(1-Benzofuran-5-yloxy)methyl]pyridine
[0363] A solution of 1-benzofuran-5-ol in anhydrous N,N-dimethylformamide (2 mL) was added drop-wise over 5 minutes to a suspension of sodium hydride (60% in mineral oil, 168 mg, 4.21 mmol) in anhydrous N,N-dimethylformamide (2 mL) at 0° C. The mixture was stirred at 0° C. for 15 minutes before the addition of a solution of 3-(bromomethyl)pyridine hydrobromide (469 mg, 1.85 mmol) in anhydrous N,N-dimethylformamide (3 mL). The mixture was stirred at room temperature for 18 hours, then quenched by the addition of water (5 mL) and extracted with ethyl acetate (3×15 mL). Combined organic extracts were washed with brine (3×10 mL), dried, filtered and concentrated to give the title compound 376 mg (99% yield) as a brown solid. δ.sub.H NMR (500 MHz, chloroform) 8.71 (d, J=1.76 Hz, 1H), 8.59 (dd, J=1.47, 4.83 Hz, 1H), 7.81 (d, J=7.83 Hz, 1H), 7.61 (d, J=2.14 Hz, 1H), 7.41 (d, J=8.91 Hz, 1H), 7.34 (dd, J=4.85, 7.79 Hz, 1H), 7.13 (d, J=2.56 Hz, 1H), 6.98 (dd, J=2.58, 8.91 Hz, 1H), 6.71 (dd, J=0.69, 2.06 Hz, 1H), 5.12 (s, 2H). Tr(METCR1278)=1.39 min, (ES.sup.+)(M+H).sup.+ 226.
Step 2, Method 7: 5-(Pyridin-3-ylmethoxy)-1-benzofuran-2-carbaldehyde
[0364] 3-[(1-Benzofuran-5-yloxy)methyl]pyridine (370 mg, 1.64 mmol) was dissolved in anhydrous tetrahydrofuran (8 mL) under nitrogen and cooled to −78° C. 1.6 M n-butyllithium in hexanes (1.54 mL, 2.46 mmol) was added drop-wise over 5 minutes and the solution stirred for 30 minutes. Anhydrous N,N-dimethylformamide (318 μL, 4.11 mmol) was then added and the mixture stirred for 18 hours. The reaction mixture was quenched by the addition of water (10 mL) and extracted with ethyl acetate (3×15 mL). The combined organic extracts were washed with brine (3×10 mL), then dried, filtered and concentrated. Purification by FCC (silica, 12-100% ethyl acetate in heptane) gave the title compound 52 mg (13% yield) as a white powder. δ.sub.H NMR (500 MHz, DMSO) 9.83 (s, 1H), 8.71 (d, J=1.74 Hz, 1H), 8.56 (dd, J=1.54, 4.79 Hz, 1H), 7.96-7.85 (m, 2H), 7.68 (d, J=9.09 Hz, 1H), 7.50 (d, J=2.58 Hz, 1H), 7.44 (dd, J=4.80, 7.47 Hz, 1H), 7.29 (dd, J=2.65, 9.08 Hz, 1H), 5.22 (s, 2H). Tr(METCR1278)=1.29 min, (ES.sup.+)(M+H).sup.+ 254.
Step 3, Method 7: 3-(Methylamino)-2-[5-(pyridin-3-ylmethoxy)-1-benzofuran-2-yl]imidazo[1,2-a]pyridine-7-carbonitrile
[0365] 5-(Pyridin-3-ylmethoxy)-1-benzofuran-2-carbaldehyde (50 mg, 0.20 mmol) and 2-aminoisonicotinonitrile (24 mg, 0.20 mmol) were dissolved in methanol (2 mL). Acetic acid (0.2 mL) and methyl isocyanide (9 μL, 0.20 mmol) were added and the mixture stirred at room temperature for 16 hours. The reaction mixture was quenched with 1 M hydrochloric acid (2 mL) and concentrated. A precipitate formed, which was collected by filtration. The solid was washed with methyl tert-butyl ether (5 mL) and dried under suction. This powder was then partitioned between ethyl acetate and saturated aqueous sodium bicarbonate. The mixture was extracted with ethyl acetate (3×10 mL). The combined organic extracts were washed with brine (2×10 mL), dried, filtered and concentrated to give the title compound 8 mg (10% yield) as a yellow powder.
Example 1, Method 7: 3-(Methylamino)-2-[5-(pyridin-3-ylmethoxy)-1-benzofuran-2-yl]imidazo[1,2-a]pyridine-7-carbonitrile
[0366] δ.sub.H NMR (500 MHz, DMSO) 8.71 (d, J=1.71 Hz, 1H), 8.55 (dd, J=1.53, 4.79 Hz, 1H), 8.45-8.36 (m, 1H), 8.22 (s, 1H), 7.91 (d, J=7.89 Hz, 1H), 7.56 (d, J=8.89 Hz, 1H), 7.44 (dd, J=4.80, 7.63 Hz, 1H), 7.32 (d, J=2.55 Hz, 1H), 7.28-7.24 (m, 1H), 7.18 (dd, J=1.57, 7.15 Hz, 1H), 7.02 (dd, J=2.60, 8.89 Hz, 1H), 5.44 (q, J=5.44 Hz, 1H), 5.21 (s, 2H), 2.89 (d, J=5.46 Hz, 3H). Tr(MET-uHPLC-AB-101)=2.23 min, (ES.sup.+)(M+H).sup.+ 396.
[0367] The following example was prepared using Method 7 described above:
TABLE-US-00007 TABLE 7 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 8
Scheme for Method 8
[0368] ##STR00055##
Step 1, Method 8: 2-[5-(2-Fluoroethoxy)-1-benzofuran-2-yl]-3-[(2,4,4-trimethylpentan-2-yl)amino]imidazo[1,2-a]pyridine-7-carbonitrile
[0369] Prepared according to method 3, using 2,4,4-trimethylpentan-2-yl isocyanide. δ.sub.H NMR (500 MHz, DMSO) 8.55 (d, J=7.2 Hz, 1H), 8.26 (s, 1H), 7.52 (d, J=8.9 Hz, 1H), 7.37 (s, 1H), 7.25 (d, J=2.4 Hz, 1H), 7.20 (d, J=7.2 Hz, 1H), 6.98 (dd, J=8.9, 2.5 Hz, 1H), 4.77 (dt, J=48.0, 3.7 Hz, 2H), 4.65 (s, 1H), 4.35-4.18 (m, 2H), 1.72 (s, 2H), 1.06 (s, 9H), 1.05 (s, 6H). Tr(METCR1278)=2.58 min, (ES.sup.+)(M+H).sup.+ 449, 86%.
Step 2, Method 8: 3-Amino-2-[5-(2-fluoroethoxy)-1-benzofuran-2-yl]imidazo[1,2-a]pyridine-7-carbonitrile
[0370] 2-[5-(2-Fluoroethoxy)-1-benzofuran-2-yl]-3-[(2,4,4-trimethylpentan-2-yl)amino]imidazo[1,2-a]pyridine-7-carbonitrile (86%, 1.50 g, 2.88 mmol) was dissolved in 4 M hydrochloric acid in dioxane (10 mL), instantly forming a yellow precipitate. Water (1 mL) was added and the reaction mixture was stirred at room temperature. After 30 minutes, the solid was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate (1:1, ca. 100 mL) and extracted with further ethyl acetate (3×50 mL) and then dichloromethane (3×50 mL). The aqueous layer was filtered (GF/F paper), washed with methyl tert-butyl ether (10 mL) and dried under suction to give the title compound 264 mg (28% yield) as a yellow-orange powder.
Example 1, Method 8: 3-Amino-2-[5-(2-fluoroethoxy)-1-benzofuran-2-yl]imidazo[1,2-a]pyridine-7-carbonitrile
[0371] δ.sub.H NMR (500 MHz, DMSO) 8.34 (d, J=7.2 Hz, 1H), 8.10 (s, 1H), 7.54 (d, J=8.9 Hz, 1H), 7.19 (d, J=2.5 Hz, 1H), 7.16 (s, 1H), 7.10 (dd, J=7.2, 1.5 Hz, 1H), 6.92 (dd, J=8.9, 2.6 Hz, 1H), 6.41 (s, 2H), 4.85-4.70 (m, 2H), 4.34-4.22 (m, 2H). Tr(MET-uHPLC-AB-101)=2.78 min, (ES.sup.+)(M+H).sup.+ 337.
[0372] The following examples were prepared using Method 8 described above.
TABLE-US-00008 TABLE 8 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 9
Scheme for Method 9
[0373] ##STR00059##
Step 1, Method 9: 3-{[Benzyl(methyl)amino]methyl}-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile
[0374] 2-(5-Methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile (prepared according to Method 5, 50 mg, 0.17 mmol) was suspended in acetic acid (2 mL) and treated with 37% aqueous formaldehyde (13 μL, 0.17 mmol). N-Methyl-benzylamine (22 μL, 0.17 mmol) was added and the mixture heated to 70° C. for 18 hours. The reaction mixture was cooled to room temperature and basified with saturated aqueous sodium bicarbonate. The solution was extracted with ethyl acetate (2×10 mL), dried, filtered and concentrated. The material was dissolved in 2:1 acetonitrile:DMSO (2 mL); on standing a precipitate formed. The solid was collected by filtration, washed with methyl tert-butyl ether (2×5 mL) and dried under vacuum to give the title compound 20 mg (27% yield) as a yellow powder. δ.sub.H NMR (500 MHz, DMSO) 8.64 (d, J=7.1 Hz, 1H), 8.37 (s, 1H), 7.57 (d, J=8.9 Hz, 1H), 7.37 (s, 1H), 7.34 (dd, J=7.1, 1.6 Hz, 1H), 7.30-7.17 (m, 6H), 6.96 (dd, J=8.9, 2.6 Hz, 1H), 4.36 (s, 2H), 3.82 (s, 3H), 3.61 (s, 2H), 2.12 (s, 3H). Tr(METCR1278)=1.60 min, (ES.sup.+)(M+H).sup.+ 423.
Step 2, Method 9: 2-(5-Methoxy-1-benzofuran-2-yl)-3-(methoxymethyl)imidazo[1,2-a]pyridine-7-carbonitrile
[0375] 3-{[Benzyl(methyl)amino]methyl}-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile (20 mg, 0.05 mmol) was suspended in 1,2-dichloroethane (2 mL) and treated with 1-chloroethyl chloroformate (20 μL, 0.19 mmol). The mixture was heated to 55° C. for 18 hours. The reaction mixture was concentrated to dryness and the residue then dissolved in methanol (5 mL). The solution was heated to 50° C. for 90 minutes. The reaction mixture was concentrated to dryness to give a yellow powder. The powder was dissolved in methanol (1 mL) and the product precipitated with a single drop of water. The solid was collected by filtration and washed with methyl tert-butyl ether (5 mL), then dried under suction to give the title compound 7 mg (44% yield) as an off-white powder.
Example 1, Method 9: 2-(5-Methoxy-1-benzofuran-2-yl)-3-(methoxymethyl)imidazo[1,2-a]pyridine-7-carbonitrile
[0376] δ.sub.H NMR (500 MHz, DMSO) 8.70-8.57 (m, 1H), 8.50-8.35 (m, 1H), 7.60 (d, J=8.9 Hz, 1H), 7.39 (s, 1H), 7.34 (dd, J=7.1, 1.6 Hz, 1H), 7.24 (d, J=2.6 Hz, 1H), 6.96 (dd, J=8.9, 2.6 Hz, 1H), 5.20 (s, 2H), 3.81 (s, 3H), 3.36 (s, 3H). Tr(MET-uHPLC-AB-101)=3.26 min, (ES.sup.+)(M+H).sup.+ 334.
[0377] The following examples were prepared using Method 9 described above.
TABLE-US-00009 TABLE 9 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 10
Scheme for Method 10
[0378] ##STR00062##
Step 1, Method 10: [2-(1-Benzofuran-5-yloxy)ethyl]dimethylamine
[0379] 1-Benzofuran-5-ol (100 mg, 0.75 mmol) was dissolved in N,N-dimethylformamide (3 mL) and treated with potassium carbonate (309 mg, 2.24 mmol) and 2-chloro-N,N-dimethylethanamine hydrochloride (107 mg, 0.75 mmol). The reaction mixture was stirred at room temperature for 16 hours then heated to 60° C. for 5 hours. The reaction mixture was then concentrated and the residue was partitioned between ethyl acetate (10 mL) and water (10 mL). The layers were separated and the aqueous extracted with ethyl acetate (10 mL). The combined organic extracts were washed with brine (10 mL), dried, filtered and concentrated. The residue was purified using an SCX column to give the title compound 67 mg (44% yield) as an orange oil. δ.sub.H NMR (500 MHz, chloroform) 7.59 (d, J=2.1 Hz, 1H), 7.38 (d, J=8.9 Hz, 1H), 7.07 (d, J=2.5 Hz, 1H), 6.93 (dd, J=8.9, 2.6 Hz, 1H), 6.70 (dd, J=2.1, 0.8 Hz, 1H), 4.10 (t, J=5.8 Hz, 2H), 2.76 (t, J=5.8 Hz, 2H), 2.36 (s, 6H). Tr(METCR1278)=0.91 min, (ES.sup.+) (M+H).sup.+ 206.
Step 2, Method 10: 5-[2-(Dimethylamino)ethoxy]-1-benzofuran-2-carbaldehyde
[0380] [2-(1-Benzofuran-5-yloxy)ethyl]dimethylamine (65 mg, 0.32 mmol) was dissolved in anhydrous tetrahydrofuran (3 mL) under nitrogen and cooled to −78° C. 1.6 M n-Butyllithium in hexanes (300 μL, 0.48 mmol) was added drop-wise over 2 minutes and the mixture stirred at −78° C. for 10 minutes. A light yellow precipitate formed. N,N-dimethylformamide (50 μL, 0.63 mmol) was added and the mixture allowed to warm to room temperature and stirred for 45 minutes. The reaction mixture was then quenched with water (10 mL) and extracted with ethyl acetate (3×10 mL). Combined organic extracts were washed with brine (10 mL), dried, filtered and concentrated to give the title compound 67 mg (46% yield) as a yellow oil. Tr(METCR1278)=0.98 min, (ES.sup.+) (M+H).sup.+ 234.
Step 3, Method 10: 2-{5-[2-(Dimethylamino)ethoxy]-1-benzofuran-2-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0381] 5-[2-(Dimethylamino)ethoxy]-1-benzofuran-2-carbaldehyde (65 mg, 0.14 mmol) and 2-aminoisonicotinonitrile (17 mg, 0.14 mmol) were dissolved in methanol (2 mL). Acetic acid (0.2 mL) and methyl isocyanide (7 μL, 0.14 mmol) were added and the mixture stirred at room temperature for 22 hours. The reaction mixture was quenched with 1 M hydrochloric acid (1 mL) and stirred at room temperature for 10 minutes. The organic solvents were removed in vacuo and the aqueous neutralised with saturated aqueous sodium bicarbonate. The solution was extracted with ethyl acetate (3×10 mL). Combined organic extracts were washed with brine (10 mL), dried, filtered and concentrated. Purification by preparative HPLC (acetonitrile-water-0.1% formic acid) then by SCX column gave the title compound 5 mg (9% yield) as a yellow powder.
Example 1, Method 10: 2-{5-[2-(Dimethylamino)ethoxy]-1-benzofuran-2-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0382] δ.sub.H NMR (500 MHz, DMSO) 8.41 (d, J=7.2 Hz, 1H), 8.22 (s, 1H), 7.53 (d, J=8.9 Hz, 1H), 7.25 (s, 1H), 7.21 (d, J=2.5 Hz, 1H), 7.18 (dd, J=7.2, 1.6 Hz, 1H), 6.91 (dd, J=8.9, 2.6 Hz, 1H), 5.44 (q, J=5.5 Hz, 1H), 4.09 (t, J=5.9 Hz, 2H), 2.88 (d, J=5.5 Hz, 3H), 2.69-2.61 (m, 2H), 2.24 (s, 6H). Tr(MET-uHPLC-AB-101)=1.69 min, (ES.sup.+) (M+H).sup.+ 376.
[0383] The following example was prepared using Method 10 described above:
TABLE-US-00010 TABLE 10 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 11
Scheme for Method 11
[0384] ##STR00065##
Step 1, Method 11: 4-[(Pyridin-3-ylmethoxy)methyl]benzaldehyde
[0385] 4-(Hydroxymethyl)benzaldehyde (100 mg, 0.72 mmol) and 3-(bromomethyl)pyridine hydrochloride (182 mg, 0.72 mmol) were dissolved in dichloromethane (2 mL). A solution of potassium hydroxide (404 mg, 7.2 mmol) in water (2 mL) was added, followed by tributylammonium chloride (20 mg, 0.07 mmol) and the mixture was heated to reflux for 16 hours. The reaction mixture was diluted with dichloromethane (10 mL) then washed with water (10 mL) and brine (10 mL). The dichloromethane layer was dried, filtered and concentrated. The residue was purified by FCC (silica, 20%-100% ethyl acetate in heptane) to give the title compound 52 mg (31% yield) as a colourless oil. δ.sub.H NMR (500 MHz, chloroform) 10.02 (s, 1H), 8.70-8.59 (m, 1H), 8.59-8.53 (m, 1H), 7.88 (d, J=8.1 Hz, 2H), 7.73 (d, J=7.8 Hz, 1H), 7.53 (d, J=8.0 Hz, 2H), 7.32 (dd, J=7.8, 4.9 Hz, 1H), 4.66 (s, 2H), 4.62 (s, 2H). Tr(METCR1278)=1.09 min, (ES.sup.+) (M+H).sup.+ 228.
Step 2, Method 11: 3-(Methylamino)-2-{4-[(pyridin-3-ylmethoxy)methyl]phenyl}imidazo[1,2-a]pyridine-7-carbonitrile
[0386] 4-[(Pyridin-3-ylmethoxy)methyl]benzaldehyde (50 mg, 0.22 mmol) and 2-aminoisonicotinonitrile (26 mg, 0.22 mmol) were dissolved in methanol (2 mL). Acetic acid (0.2 mL) and methyl isocyanide (12 μL, 0.22 mmol) were added and the mixture stirred at room temperature. The reaction mixture was quenched with 1 M hydrochloric acid (2 mL) and stirred at room temperature for 10 minutes. The organic solvents were removed in vacuo and the aqueous neutralised with saturated aqueous sodium bicarbonate. The solution was extracted with ethyl acetate (3×10 mL). The combined organic extracts were washed with brine (2×10 mL), dried, filtered and concentrated. Purification by preparative HPLC (acetonitrile-water-0.2% ammonium hydroxide) gave the title compound 28 mg (34% yield) as a yellow glass.
Example 1, Method 11: 3-(Methylamino)-2-{4-[(pyridin-3-ylmethoxy)methyl]phenyl}imidazo[1,2-a]pyridine-7-carbonitrile
[0387] δ.sub.H NMR (500 MHz, DMSO) 8.59 (d, J=1.5 Hz, 1H), 8.52 (dd, J=4.7, 1.4 Hz, 1H), 8.42 (d, J=7.1 Hz, 1H), 8.22 (s, 1H), 8.08 (d, J=8.2 Hz, 2H), 7.80 (d, J=7.8 Hz, 1H), 7.47 (d, J=8.2 Hz, 2H), 7.41 (dd, J=7.7, 4.8 Hz, 1H), 7.18 (dd, J=7.1, 1.5 Hz, 1H), 5.13 (q, J=5.4 Hz, 1H), 4.61 (s, 4H), 2.72 (d, J=5.4 Hz, 3H). Tr(MET-uHPLC-AB-101)=1.65 min, (ES.sup.+)(M+H).sup.+ 370.
[0388] The following examples were prepared using Method 11 described above:
TABLE-US-00011 TABLE 11 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 12
Scheme for Method 12
[0389] ##STR00068##
Step 1, Method 12: tert-Butyl N-[7-cyano-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridin-3-yl]carbamate
[0390] 3-Amino-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile hydrochloride (prepared according to Method 8, 800 mg, 2.21 mmol) was suspended in anhydrous tetrahydrofuran (10 mL) under nitrogen. Triethylamine (308 μL, 2.21 mmol), Di-tert-butyl dicarbonate (963 mg, 4.41 mmol) and N,N-dimethylaminopyridine (27 mg, 0.22 mmol) were added and the mixture stirred at 60° C. for 18 hours. The reaction mixture was treated with additional triethylamine (308 μL, 2.21 mmol) and di-tert-butyl dicarbonate (963 mg, 4.41 mmol) and heated for 22 hours. Additional di-tert-butyl dicarbonate (963 mg, 4.41 mmol) was added and the mixture heated for 68 hours. Additional di-tert-butyl dicarbonate (963 mg, 4.41 mmol) and N,N-dimethylaminopyridine (50 mg) were added and the mixture heated for 2 hours. Additional di-tert-butyl dicarbonate (963 mg, 4.41 mmol) was added and the mixture heated for 2 hours. The reaction mixture was concentrated then dissolved in acetonitrile (20 mL) and treated with lithium iodide (590 mg, 4.41 mmol), heated to 70° C. and stirred at this temperature for 1 hour. The mixture was cooled to room temperature and concentrated. Purification by FCC (silica, 12%-100% ethyl acetate in heptane) gave the title compound 399 mg (33% yield) as an orange powder. δ.sub.H NMR (250 MHz, DMSO) 9.15 (s, 1H), 8.27 (dd, J=8.3, 1.3 Hz, 2H), 7.47 (d, J=8.9 Hz, 1H), 7.31-7.20 (m, 3H), 6.96 (dd, J=8.9, 2.6 Hz, 1H), 3.84 (s, 3H), 1.45 (s, 9H). Tr(METCR1278)=2.00 min, (ES.sup.+) (M+H).sup.+ 405, 78%.
Step 2, Method 12: tert-Butyl N-[7-cyano-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridin-3-yl]-N-[2-(dimethylamino)ethyl]carbamate
[0391] tert-Butyl N-[7-cyano-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridin-3-yl]carbamate (207 mg, 0.51 mmol) was dissolved in anhydrous N,N-dimethylformamide (10 mL). Sodium hydride (60% in mineral oil, 51 mg, 1.3 mmol) was added and the mixture stirred at room temperature for 10 minutes. 2-Chloro-N,N-dimethylethanamine hydrochloride (73 mg, 0.51 mmol) was added and the mixture stirred at room temperature for 18 hours. Additional sodium hydride (60% in mineral oil, 51 mg, 1.3 mmol) and 2-chloro-N,N-dimethylethanamine hydrochloride (73 mg, 0.51 mmol) were added and the mixture stirred at room temperature for 24 hours. Additional sodium hydride (60% in mineral oil, 51 mg, 1.3 mmol) and 2-chloro-N,N-dimethylethanamine hydrochloride (73 mg, 0.51 mmol) were added and the mixture stirred at room temperature for 18 hours. The reaction mixture was quenched by the addition of water (10 mL) then extracted with ethyl acetate (3×15 mL). Combined organic extracts were washed with brine (5×10 mL), dried, filtered and concentrated. Purification by FCC (silica, ethyl acetate then 5-10% methanol in ethyl acetate) gave the title compound 25 mg (9% yield) as an orange oil. Tr(METCR1278)=1.59 min, (ES.sup.+)(M+H).sup.+ 476, 83%.
Step 3, Method 12: 3-{[2-(Dimethylamino)ethyl]amino}-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile
[0392] tert-Butyl-N-[7-cyano-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridin-3-yl]-N-[2-(dimethylamino)ethyl]carbamate (25 mg, 0.04 mmol) was dissolved in 4 M hydrochloric acid in dioxane (1 mL) and stirred at room temperature for 1 hour. Additional 4 M hydrochloric acid in dioxane (1 mL) was added and the mixture stirred for 4 hours. The reaction mixture was then concentrated and re-treated with 4 M hydrochloric acid in dioxane (1 mL) and water (0.3 mL). The reaction mixture was concentrated and purified by preparative HPLC (acetonitrile-water-0.2% ammonium hydroxide) to give the title compound 6 mg (37% yield) as a yellow powder.
Example 1, Method 12: 3-{[2-(Dimethylamino)ethyl]amino}-2-(5-methoxy-1-benzofuran-2-yl)imidazo[1,2-a]pyridine-7-carbonitrile
[0393] δ.sub.H NMR (500 MHz, DMSO) 8.53-8.41 (m, 1H), 8.22 (s, 1H), 7.51 (d, J=8.9 Hz, 1H), 7.32-7.25 (m, 1H), 7.23-7.13 (m, 2H), 6.92 (dd, J=8.9, 2.6 Hz, 1H), 5.38 (t, J=6.2 Hz, 1H), 3.81 (s, 3H), 3.22 (q, J=6.1 Hz, 2H), 2.42 (t, J=6.1 Hz, 2H), 2.15 (s, 6H). Tr(MET-uHPLC-AB-101)=1.71 min, (ES.sup.+)(M+H).sup.+ 376.
[0394] The following example was prepared using Method 12 described above:
TABLE-US-00012 TABLE 12 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 13
Scheme for Method 13
[0395] ##STR00071##
Step 1, Method β: tert-Butyl 4H,5H,6H,7H-furo[3,2-c]pyridine-5-carboxylate
[0396] 4,5,6,7-Tetrahydrofuro[3,2-c]pyridine (425 mg, 3.45 mmol) was dissolved in dichloromethane (10 mL) and cooled to 0° C. Di tert-butyl dicarbonate (753 mg, 3.45 mmol) was added and the mixture stirred, allowing warming to room temperature over 16 hours. The reaction mixture was concentrated to give the title compound 801 mg (quantitative yield) as an orange syrup. δ.sub.H NMR (500 MHz, chloroform) 7.29 (s, 1H), 6.23 (d, J=1.6 Hz, 1H), 4.34 (s, 2H), 3.72 (s, 2H), 2.69 (s, 2H), 1.48 (s, 9H). Tr(METCR1278)=1.99 min, (ES.sup.+) (M-Boc+H).sup.+ 124.
Step 2, Method 13: tert-Butyl 2-formyl-4H,5H,6H,7H-furo[3,2-c]pyridine-5-carboxylate
[0397] tert-Butyl 4H,5H,6H,7H-furo[3,2-c]pyridine-5-carboxylate (50 mg, 0.22 mmol) was dissolved in anhydrous tetrahydrofuran (3 mL) under nitrogen and cooled to −78° C. 1.5 M tert-butyllithium in pentane (0.30 mL, 0.45 mmol) was added drop-wise over 2 minutes and the mixture stirred at −78° C. for 15 minutes. Anhydrous N,N-dimethylformamide (52 uL, 0.67 mmol) was added and the mixture stirred at −78° C. The reaction mixture was quenched with water (5 mL) and extracted with ethyl acetate (3×10 mL). The combined organic extracts were washed with brine (10 mL), dried, filtered and concentrated. Purification by FCC (silica, 25% ethyl acetate in heptane) gave the title compound 26 mg (37% yield) as a colourless oil. H NMR (500 MHz, chloroform) 9.53 (s, 1H), 7.07 (s, 1H), 4.40 (br. s, 2H), 3.76 (br. s, 2H), 2.80 (br. s, 2H), 1.47 (s, 9H).
Step 3, Method 13: tert-Butyl 2-[7-cyano-3-(methylamino)imidazo[1,2-a]pyridin-2-yl]-4H,5H,6H,7H-furo[3,2-c]pyridine-5-carboxylate
[0398] tert-Butyl 2-formyl-4H,5H,6H,7H-furo[3,2-c]pyridine-5-carboxylate (26 mg, 0.1 mmol) and 2-aminoisonicotinonitrile (10 mg, 0.08 mmol) were dissolved in methanol (1 mL). Acetic acid (0.1 mL) and methyl isocyanide (10 μL, 0.19 mmol) were added and the mixture stirred at room temperature for 72 hours. The reaction mixture was quenched with 1 M hydrochloric acid (2 mL) and stirred at room temperature for 30 minutes. The organic solvents were removed in vacuo and the aqueous neutralised with saturated aqueous sodium bicarbonate. The solution was extracted with ethyl acetate (3×10 mL). The combined organic extracts were washed with brine (2×10 mL), dried, filtered and concentrated. The residue was purified by preparative HPLC (acetonitrile-water-0.1% formic acid) to give the title compound 6 mg (18% yield) as a yellow powder.
Example 1, Method 13: tert-Butyl 2-[7-cyano-3-(methylamino)imidazo[1,2-a]pyridin-2-yl]-4H,5H,6H,7H-furo[3,2-c]pyridine-5-carboxylate
[0399] δ.sub.H NMR (500 MHz, DMSO) 8.38-8.29 (m, 1H), 8.14 (s, 1H), 7.15 (dd, J=7.1, 1.6 Hz, 1H), 6.82 (s, 1H), 5.13 (q, J=5.4 Hz, 1H), 4.34 (s, 2H), 3.70 (t, J=5.7 Hz, 2H), 2.78 (d, J=5.5 Hz, 3H), 2.75 (t, J=5.6 Hz, 2H), 1.43 (s, 9H). Tr(MET-uHPLC-AB-101)=3.29 min, (ES.sup.+)(M+H).sup.+ 394.
[0400] The following example was prepared using Method 13 described above:
TABLE-US-00013 TABLE 13 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 14
Scheme for Method 14
[0401] ##STR00074##
Step 1, Method 14: tert-Butyl N-{[2-(5-methoxy-1-benzofuran-2-yl)-3-(methylamino)imidazo[1,2-a]pyridin-7-yl]methyl}carbamate
[0402] 5-Methoxy-1-benzofuran-2-carbaldehyde (200 mg, 1.13 mmol) and tert-butyl N-[(2-aminopyridin-4-yl)methyl]carbamate (253 mg, 1.14 mmol) were suspended in methanol (5 mL). Acetic acid (0.5 mL) and methyl isocyanide (59 μL, 1.13 mmol) were added and the mixture stirred at room temperature for 18 hours. The reaction mixture was quenched with 1 M hydrochloric acid (2 mL) and stirred at room temperature for 10 minutes. The organic solvents were removed in vacuo and the aqueous neutralised with saturated aqueous sodium bicarbonate. The solution was extracted with ethyl acetate (3×10 mL). The combined organic extracts were washed with brine (2×10 mL), dried, filtered and concentrated. Purification by FCC (silica, 25-100% ethyl acetate in heptane) gave the title compound 153 mg (31% yield) as a yellow powder. Tr(MET-uHPLC-AB-101)=2.38 min, (ES.sup.+) (M+H).sup.+ 423, 92%.
Step 2, Method 14: 7-(Aminomethyl)-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine
[0403] tert-Butyl-N-{[2-(5-methoxy-1-benzofuran-2-yl)-3-(methylamino)imidazo[1,2-a]pyridin-7-yl]methyl}carbamate (159 mg, 0.35 mmol) was dissolved in 4 M hydrochloric acid in dioxane (2 mL) and treated with water (0.2 mL). The mixture was stirred at room temperature for 1.5 hours. The reaction mixture was then concentrated and the residue was twice re-suspended in methyl tert-butyl ether (10 mL) and concentrated. Purification by preparative HPLC (acetonitrile-water) followed by SCX gave the title compound 9.9 mg (11% yield) as an orange solid.
Example 1, Method 14: 7-(Aminomethyl)-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine
[0404] δ.sub.H NMR (500 MHz, DMSO) 8.19 (d, J=7.0 Hz, 1H), 7.50 (d, J=8.9 Hz, 1H), 7.38 (s, 1H), 7.16 (d, J=2.6 Hz, 1H), 7.15 (s, 1H), 6.91 (dd, J=7.1, 1.4 Hz, 1H), 6.87 (dd, J=8.9, 2.6 Hz, 1H), 4.93 (q, J=5.5 Hz, 1H), 3.80 (s, 3H), 3.76 (s, 2H), 2.81 (d, J=5.5 Hz, 3H). Tr(MET-uHPLC-AB-101)=1.32 min, (ES.sup.+) (M+H).sup.+ 323.
[0405] The following example was prepared using Method 14 described above:
TABLE-US-00014 TABLE 14 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 15
Scheme for Method 15
[0406] ##STR00076##
Step 1, Method 15: Methyl 5-methoxypyrazine-2-carboxylate
[0407] Methyl 5-chloropyrazine-2-carboxylate (2 g, 11.6 mmol) was dissolved in a 0.5 M sodium methoxide in methanol (27.8 mL, 13.9 mmol) under nitrogen. The mixture was refluxed for 15 minutes. The mixture was then dissolved with water (80 mL) and extracted with ethyl acetate (2×100 mL). The combined organic extracts were dried, filtered and concentrated to give the title compound 1.68 g (79% yield) as a white powder. δ.sub.H NMR (500 MHz, chloroform) 8.88 (d, J=1.2 Hz, 1H), 8.28 (d, J=1.2 Hz, 1H), 4.05 (s, 3H), 4.00 (s, 3H). Tr(METCR1278)=1.23 min, (ES.sup.+) (M+H).sup.+ 169.
Step 2, Method 15: (5-Methoxypyrazin-2-yl)methanol
[0408] Sodium borohydride (12.2 g, 323 mmol) was added to a stirred solution of methyl 5-methoxypyrazine-2-carboxylate (18.1 g, 108 mmol) in tetrahydrofuran (400 mL) under nitrogen. The mixture was refluxed for 15 minutes, after which methanol (40 mL) was added slowly. The reaction was refluxed for 1.5 hours then cooled to room temperature. The mixture was then quenched using water (200 mL), then extracted with ethyl acetate (3×150 mL). The combined organic extracts were dried, filtered and concentrated to give the title compound 9.33 g (62% yield) as a light yellow powder. δ.sub.H NMR (500 MHz, DMSO) 8.28-8.16 (m, 2H), 5.41 (t, J=5.8 Hz, 1H), 4.54 (d, J=5.6 Hz, 2H), 3.90 (s, 3H). Tr(METCR1278)=0.74 min, (ES.sup.+) (M+H).sup.+ 141.
Step 3, Method 15: (5-Methoxypyrazin-2-yl)methyl methanesulfonate
[0409] (5-Methoxypyrazin-2-yl)methanol (73 mg, 0.52 mmol) was dissolved in dichloromethane (1 mL) under nitrogen. Triethylamine (0.08 mL, 0.73 mmol) was added, followed by methanesulfonyl chloride (42 μL, 0.55 mmol). The mixture was stirred at room temperature for 1 hour. The mixture was partitioned between dichloromethane (10 mL) and water (10 mL). The organic phase was dried, filtered and concentrated to give the title compound 59 mg (52% yield) as a yellow oil. Tr(METCR1278)=1.25 min, (ES.sup.+) (M+H).sup.+ 219.
Step 4, Method 15: 4-[(5-Methoxypyrazin-2-yl)methoxy]benzaldehyde
[0410] A suspension of 4-hydroxybenzaldehyde (104 mg, 0.85 mmol), potassium carbonate (236 mg, 1.71 mmol) and (5-methoxypyrazin-2-yl)methyl methanesulfonate (73%, 255 mg, 0.85 mmol) in acetone (10 mL) was heated to reflux for 16 hours. The reaction mixture was filtered and concentrated. Purification by FCC (silica, 6-50% ethyl acetate in heptane) gave the title compound 101 mg (48% yield) as a white powder. δ.sub.H NMR (500 MHz, DMSO) 9.90 (s, 1H), 8.27 (s, 1H), 8.24 (s, 1H), 7.95-7.72 (m, 2H), 7.11 (d, J=8.7 Hz, 2H), 5.23 (s, 2H), 3.99 (s, 3H). Tr(METCR1278)=1.71 min, (ES.sup.+) (M+H).sup.+ 245.
Step 5, Method 15: 2-{4-[(5-Methoxypyrazin-2-yl)methoxy]phenyl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0411] 4-[(5-Methoxypyrazin-2-yl)methoxy]benzaldehyde (101 mg, 0.41 mmol) and 2-aminoisonicotinonitrile (49 mg, 0.41 mmol) were dissolved in methanol (2 mL). Acetic acid (0.2 mL) and methyl isocyanide (22 μL, 0.41 mmol) were added and the mixture stirred at room temperature. After 18 hours, the reaction mixture was filtered, and the collected solid washed with methyl tert-butyl ether (2×5 mL). Drying under suction gave the title compound 55 mg (33% yield) as a yellow powder.
Example 1, Method 15: 2-{4-[(5-Methoxypyrazin-2-yl)methoxy]phenyl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0412] δ.sub.H NMR (500 MHz, DMSO) 8.42-8.38 (m, 2H), 8.35 (d, J=1.3 Hz, 1H), 8.18 (s, 1H), 8.04 (d, J=8.8 Hz, 2H), 7.20-7.13 (m, 3H), 5.21 (s, 2H), 5.05 (q, J=5.4 Hz, 1H), 3.93 (s, 3H), 2.71 (d, J=5.4 Hz, 3H). Tr(MET-uHPLC-AB-101)=2.67 min, (ES.sup.+) (M+H).sup.+ 387.
[0413] The following example was prepared using Method 15 described above:
TABLE-US-00015 TABLE 15 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 16
Scheme for Method 16
[0414] ##STR00081##
Step 1, Method 16: 6-[(5-Methoxypyrazin-2-yl)methoxy]pyridine-3-carbaldehyde
[0415] (5-Methoxypyrazin-2-yl)methanol (prepared according to Method 15, 200 mg, 1.43 mmol) was dissolved in anhydrous N,N-dimethylformamide (3 mL) under nitrogen. Potassium tert-butoxide (88 mg, 0.78 mmol) was added and the mixture stirred for 15 minutes. 6-Chloropyridine-3-carbaldehyde (202 mg, 1.43 mmol) was added and the mixture stirred at room temperature for 18 hours. The reaction mixture was partitioned between ethyl acetate (10 mL) and saturated aqueous sodium bicarbonate (10 mL). The suspension was extracted with ethyl acetate (3×10 mL). Combined organic layers were washed with water (2×10 mL) and brine (2×10 mL), then dried, filtered and concentrated. Purification by FCC (silica, 12-100% ethyl acetate in heptane) gave the title compound 42 mg (10% yield) as a white powder. δ.sub.H NMR (500 MHz, DMSO) 9.97 (s, 1H), 8.78 (d, J=2.3 Hz, 1H), 8.39 (s, 1H), 8.33 (s, 1H), 8.15 (dd, J=8.6, 2.3 Hz, 1H), 7.06 (d, J=8.6 Hz, 1H), 5.51 (s, 2H), 3.92 (s, 3H). Tr(METCR1278)=1.65 min, (ES.sup.+) (M+H).sup.+ 246, 81%.
Step 2, Method 16: 2-{δ-[(5-Methoxypyrazin-2-yl)methoxy]pyridin-3-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0416] 6-[(5-Methoxypyrazin-2-yl)methoxy]pyridine-3-carbaldehyde (42 mg, 0.17 mmol) and 2-aminoisonicotinonitrile (20 mg, 0.17 mmol) were dissolved in methanol (2 mL). Acetic acid (0.2 mL) and methyl isocyanide (13 μL, 0.26 mmol) were added and the mixture stirred at room temperature for 64 hours. The reaction mixture was quenched with 1 M hydrochloric acid (2 mL) and stood at room temperature for 20 minutes. The organic solvents were removed in vacuo and the aqueous neutralised with saturated aqueous sodium bicarbonate. The solution was extracted with ethyl acetate (2×10 mL). Combined organic extracts were washed with brine (10 mL), dried, filtered and concentrated. Purification by preparative HPLC (acetonitrile-water-0.2% ammonium hydroxide) gave the title compound 15 mg (21% yield) as a yellow powder.
Example 1, Method 16: 2-{6-[(5-Methoxypyrazin-2-yl)methoxy]pyridin-3-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0417] δ.sub.H NMR (500 MHz, DMSO) 8.84 (d, J=2.2 Hz, 1H), 8.42 (d, J=7.1 Hz, 1H), 8.39 (s, 1H), 8.36 (dd, J=8.6, 2.4 Hz, 1H), 8.33 (d, J=1.2 Hz, 1H), 8.22 (s, 1H), 7.19 (dd, J=7.1, 1.5 Hz, 1H), 7.02 (d, J=8.7 Hz, 1H), 5.46 (s, 2H), 5.13 (q, J=5.4 Hz, 1H), 3.92 (s, 3H), 2.72 (d, J=5.4 Hz, 3H). Tr(MET-uHPLC-AB-101)=2.78 min, (ES.sup.+) (M+H).sup.+ 388.
[0418] The following examples were prepared using Method 16 described above:
TABLE-US-00016 TABLE 16 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 17
Scheme for Method 17
[0419] ##STR00085##
Step 1, Method 17: 2-(5-Methoxy-1-benzofuran-2-yl)-N-methyl-7-[2-(trimethylsilyl) ethynyl]imidazo[1,2-a]pyridin-3-amine
[0420] 7-Bromo-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine (150 mg, 0.4 mmol, prepared by Method 1), trimethylsilylacetylene (69 PL, 0.48 mmol), copper(I) iodide (8 mg, 0.04 mmol) and bis(triphenylphosphine)palladium(II) dichloride (14 mg, 0.02 mmol) were dissolved in anhydrous dioxane (5 mL) in a pressure tube. The vessel was sealed and the mixture heated to 100° C. for 16 hours. The reaction mixture was cooled to room temperature and partitioned between ethyl acetate (20 mL) and water (20 mL). The layers were separated and the organic phase washed with brine (15 mL), then dried, filtered and concentrated. Purification by FCC (silica, δ-50% ethyl acetate in heptane) gave the title compound 87 mg (55% yield) as a yellow powder. δ.sub.H NMR (500 MHz, DMSO) 8.24 (d, J=7.1 Hz, 1H), 7.59 (s, 1H), 7.52 (d, J=8.9 Hz, 1H), 7.19 (s, 1H), 7.18 (d, J=2.6 Hz, 1H), 6.94-6.86 (m, 2H), 5.18 (q, J=5.4 Hz, 1H), 3.80 (s, 3H), 2.84 (d, J=5.5 Hz, 3H), 0.26 (s, 9H). Tr(MET-uHPLC-AB-101)=3.98 min, (ES.sup.+) (M+H).sup.+ 390.
Step 2, Method 17: 7-Ethynyl-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine
[0421] 2-(5-Methoxy-1-benzofuran-2-yl)-N-methyl-7-[2-(trimethylsilyl)ethynyl]imidazo[1,2-a]pyridin-3-amine (77 mg, 0.2 mmol) was dissolved in ethanol (3 mL) and cooled to 0° C. Potassium carbonate (44 mg, 0.32 mmol) was added and the mixture stirred at 0° C. for 1.5 hours. The reaction mixture was partitioned between ethyl acetate (15 mL) and water (15 mL). The layers were separated and the organic phase washed with brine (10 mL), then dried, filtered and concentrated to give an orange powder (47 mg). The powder was triturated in boiling 2:1 acetonitrile:DMSO and filtered. The collected solid was purified by FCC (silica, 25% ethyl acetate in heptane) to give the title compound 7 mg (12% yield) as an orange powder.
Example 1, Method 17: 7-Ethynyl-2-(5-methoxy-1-benzofuran-2-yl)-N-methylimidazo[1,2-a]pyridin-3-amine
[0422] δ.sub.H NMR (500 MHz, DMSO) 8.26 (d, J=7.1 Hz, 1H), 7.65 (s, 1H), 7.52 (d, J=8.9 Hz, 1H), 7.19 (s, 1H), 7.18 (d, J=2.6 Hz, 1H), 6.90 (m, 2H), 5.15 (q, J=5.5 Hz, 1H), 4.43 (s, 1H), 3.80 (s, 3H), 2.84 (d, J=5.5 Hz, 3H). Tr(MET-uHPLC-AB-101)=2.7 min, (ES.sup.+) (M+H).sup.+ 318.
[0423] The following examples were prepared using Method 17 described above:
TABLE-US-00017 TABLE 17 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 18
Scheme for Method 18
[0424] ##STR00089##
Step 1, Method 18: tert-Butyl N-(4-formylphenyl)-N-[(5-methoxypyridin-2-yl)methyl]carbamate
[0425] tert-Butyl N-(4-formylphenyl)carbamate (200 mg, 1.8 mmol) and 2-(chloromethyl)-5-methoxypyridine hydrochloride (175 mg, 0.90 mmol) were dissolved in anhydrous N,N-dimethylformamide (5 mL) and cooled to 0° C. Potassium iodide (15 mg, 0.09 mmol) and sodium hydride (60% in mineral oil, 108 mg, 2.71 mmol) were added and the mixture stirred at room temperature for 64 hours. The reaction mixture was quenched by the addition of water (10 mL). The solution was extracted with ethyl acetate (3×15 mL). The combined organic extracts were washed with brine (3×10 mL), dried, filtered and concentrated. Purification by FCC (silica, 6-65% ethyl acetate in heptane) gave the title compound 74 mg (24% yield) as a colourless oil. δ.sub.H NMR (500 MHz, chloroform) 9.93 (s, 1H), 8.24 (d, J=2.8 Hz, 1H), 7.90-7.71 (m, 2H), 7.49 (d, J=8.6 Hz, 2H), 7.23 (d, J=8.6 Hz, 1H), 7.18 (dd, J=8.6, 2.9 Hz, 1H), 4.97 (s, 2H), 3.85 (s, 3H), 1.42 (s, 9H). Tr(METCR1278)=1.87 min, (ES.sup.+) (M+H).sup.+ 343.
Step 2, Method 18: tert-Butyl-N-{4-[7-cyano-3-(methylamino)imidazo[1,2-a]pyridin-2-yl]phenyl}-N-[(5-methoxypyridin-2-yl)methyl]carbamate
[0426] tert-Butyl N-(4-formylphenyl)-N-[(5-methoxypyridin-2-yl)methyl]carbamate (74 mg, 0.22 mmol) and 2-aminoisonicotinonitrile (26 mg, 0.21 mmol) were dissolved in methanol (3 mL). Acetic acid (0.3 mL) and methyl isocyanide (17 μL, 0.32 mmol) were added and the mixture stirred at room temperature for 16 hours. The reaction mixture was quenched with 1 M hydrochloric acid (2 mL) and stirred at room temperature for 40 minutes. The organic solvents were removed in vacuo and the aqueous neutralised with saturated aqueous sodium bicarbonate. The solution was extracted with ethyl acetate (2×15 mL). The combined organic extracts were washed with brine (10 mL), dried, filtered and concentrated. Purification by FCC (silica, 50-100% ethyl acetate in heptane) gave the title compound 35 mg (33% yield) as a yellow powder. Tr(METCR1278)=1.27 min, (ES.sup.+) (M+H).sup.+485.
Step 3, Method 18: (2-(4-{[(5-Methoxypyridin-2-yl)methyl]amino}phenyl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0427] tert-Butyl-N-{4-[7-cyano-3-(methylamino)imidazo[1,2-a]pyridin-2-yl]phenyl}-N-[(5-methoxypyridin-2-yl)methyl]carbamate (35 mg, 0.07 mmol) was dissolved in 4 M hydrochloric acid in dioxane (1 mL) and water (0.1 mL). The mixture was stirred at room temperature for 3 hours then concentrated. Purification using an SCX column to give the title compound 22 mg (75% yield) as an orange powder.
Example 1, Method 18: (2-(4-{[(5-Methoxypyridin-2-yl)methyl]amino}phenyl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0428] δ.sub.H NMR (500 MHz, DMSO) 8.32 (d, J=7.1 Hz, 1H), 8.25 (d, J=2.7 Hz, 1H), 8.09 (s, 1H), 7.81 (d, J=8.7 Hz, 2H), 7.36 (dd, J=8.6, 2.8 Hz, 1H), 7.33 (d, J=8.6 Hz, 1H), 7.12 (dd, J=7.1, 1.6 Hz, 1H), 6.67 (d, J=8.7 Hz, 2H), 6.54 (t, J=6.0 Hz, 1H), 4.89 (q, J=5.4 Hz, 1H), 4.34 (d, J=6.1 Hz, 2H), 3.80 (s, 3H), 2.67 (d, J=5.4 Hz, 3H). Tr(MET-uHPLC-AB-101)=1.59 min, (ES.sup.+) (M+H).sup.+ 385.
[0429] The following example was prepared using Method 18 described above:
TABLE-US-00018 TABLE 18 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 19
Scheme for Method 19
[0430] ##STR00091##
Step 1, Method 19: 4-{5H,6H-Imidazo[2,1-b][1,3]thiazol-3-ylmethoxy}benzaldehyde
[0431] A suspension of 4-hydroxybenzaldehyde (100 mg, 0.82 mmol), potassium iodide (136 mg, 0.82 mmol) and 3-(chloromethyl)-5,6-dihydroimidazo[2,1-b][1,3]thiazole hydrochloride (173 mg, 0.82 mmol) in anhydrous N,N-dimethylformamide (5 mL) cooled to 0° C. under nitrogen was treated with sodium hydride (60% in mineral oil, 82 mg, 2.05 mmol). The mixture was stirred, warming to room temperature. After 20 hours, the reaction mixture was quenched with water (10 mL) and extracted with ethyl acetate (3×15 mL). Combined organic extracts were washed with brine (3×10 mL), dried, filtered and concentrated to give an off-white powder. The crude product was suspended in methyl tert-butyl ether (10 mL) and sonicated to form a fine suspension. The mixture was filtered, and the collected solid washed with further methyl tert-butyl ether (3×10 mL). Drying under suction gave the title compound 97 mg (44% yield) as an off-white powder. δ.sub.H NMR (500 MHz, DMSO) 9.89 (s, 1H), 7.89 (d, J=8.7 Hz, 2H), 7.23 (d, J=8.7 Hz, 2H), 6.10 (s, 1H), 4.96 (s, 2H), 4.06 (t, J=9.4 Hz, 2H), 3.80 (t, J=9.4 Hz, 2H). Tr(METCR1278)=0.98 min, (ES.sup.+) (M+H).sup.+ 261.
Step 2, Method 19: 2-(4-{5H,6H-Imidazo[2,1-b][1,3]thiazol-3-ylmethoxy}phenyl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0432] 4-{5H,6H-Imidazo[2,1-b][1,3]thiazol-3-ylmethoxy}benzaldehyde (97 mg, 0.37 mmol) and 2-aminoisonicotinonitrile (44 mg, 0.37 mmol) were dissolved in methanol (3 mL). Acetic acid (0.3 mL) and methyl isocyanide (29 μL, 0.29 mmol) were added and the mixture stirred at room temperature. The reaction mixture was quenched with 1 M hydrochloric acid (2 mL) and stirred at room temperature for 30 minutes. The organic solvents were removed in vacuo and the aqueous neutralised with saturated aqueous sodium bicarbonate. The solution was extracted with ethyl acetate (2×15 mL). The combined organic extracts were washed with brine (10 mL), dried, filtered and concentrated. The crude material was dissolved in 2:1 acetonitrile:DMSO (1.5 mL) and purified by preparative HPLC (acetonitrile-water-0.2% ammonium hydroxide) to give the title compound 3.2 mg (2% yield) as a yellow powder.
Example 1, Method 19: 2-(4-{5H,6H-Imidazo[2,1-b][1,3]thiazol-3-ylmethoxy}phenyl)-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0433] δ.sub.H NMR (500 MHz, DMSO) 8.40 (d, J=7.1 Hz, 1H), 8.18 (s, 1H), 8.04 (d, J=8.8 Hz, 2H), 7.28-7.02 (m, 3H), 6.08 (s, 1H), 5.05 (q, J=5.2 Hz, 1H), 4.88 (s, 2H), 4.08 (t, J=9.4 Hz, 2H), 3.83 (t, J=9.4 Hz, 2H), 2.71 (d, J=5.4 Hz, 3H). Tr(MET-uHPLC-AB-101)=1.45 min, (ES.sup.+) (M+H).sup.+ 403.
[0434] The following example was prepared using Method 19 described above:
TABLE-US-00019 TABLE 19 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Method 20
Scheme for Method 20
[0435] ##STR00093##
Step 1, Method 20: Ethyl 10-methoxy-7-thia-2,5-diazatricyclo[6.4.0.0.SUP.2,6.]dodeca-1(12),3,5,8,10-pentaene-4-carboxylate
[0436] 6-Methoxy-1,3-benzothiazol-2-amine (5 g, 27.7 mmol) was dissolved in 1,2-dimethoxyethane (60 mL). Ethyl 3-bromo-2-oxopropanoate (3.48 mL, 27.7 mmol) was added and the resulting mixture heated to reflux for 18 hours. The mixture was then cooled to room temperature and stood for 48 hours. The mixture was filtered, and collected solid washed with methyl tert-butyl ether (2×10 mL) then dried under suction. The solid was suspended in water and the mixture adjusted to pH 9 with ammonium hydroxide solution. The mixture was filtered, and collected solid washed with methyl tert-butyl ether (100 mL) then dried under suction (4.8 g). 1.45 g was purified by FCC (silica, 12-100% ethyl acetate in heptane) to give the title compound 122 mg (2% yield) as a yellow powder. δ.sub.H NMR (500 MHz, DMSO) 8.96 (s, 1H), 8.08 (d, J=8.9 Hz, 1H), 7.69 (d, J=2.5 Hz, 1H), 7.15 (dd, J=8.9, 2.5 Hz, 1H), 4.29 (q, J=7.1 Hz, 2H), 3.83 (s, 3H), 1.31 (t, J=7.1 Hz, 3H). Tr(MET-uHPLC-AB-101)=2.8 min, (ES.sup.+) (M+H).sup.+ 277.
Step 2, Method 20: {10-Methoxy-7-thia-2,5-diazatricyclo[6.4.0.0.SUP.2,6.]dodeca-1 (12),3,5,8,10-pentaen-4-yl}methanol
[0437] Ethyl 10-methoxy-7-thia-2,5-diazatricyclo[6.4.0.0.sup.2,6]dodeca-1(12),3,5,8,10-pentaene-4-carboxylate (500 mg, 1.81 mmol) was dissolved in anhydrous tetrahydrofuran (10 mL) under nitrogen and cooled to 0° C. 2.4 M Lithium aluminium hydride in tetrahydrofuran (904 μL, 2.17 mmol) was added drop-wise over 2 minutes. The reaction mixture was stirred at room temperature for 18 hours then quenched by the addition of water (60 μL) and 2 M sodium hydroxide (100 μL). The quenched mixture was then filtered through celite, washed with ethyl acetate (20 mL) and the filtrate concentrated to give the title compound 90 mg (19% yield) as a yellow powder. δ.sub.H NMR (500 MHz, DMSO) 8.04 (s, 1H), 7.91 (d, J=8.8 Hz, 1H), 7.63 (d, J=2.5 Hz, 1H), 7.10 (dd, J=8.8, 2.5 Hz, 1H), 5.10 (s, 1H), 4.47 (s, 2H), 3.82 (s, 3H). Tr(METCR1673)=0.84 min, (ES.sup.+) (M+H).sup.+ 235, 89%.
Step 3, Method 20: 10-Methoxy-7-thia-2,5-diazatricyclo[6.4.0.0.SUP.2,6.]dodeca-1(12),3,5,8,10-pentaene-4-carbaldehyde
[0438] {10-Methoxy-7-thia-2,5-diazatricyclo[6.4.0.0.sup.26]dodeca-1(12),3,5,8,10-pentaen-4-yl}methanol (90%, 80 mg, 0.31 mmol) was dissolved in dichloromethane (5 mL) and treated with Dess-Martin periodinane (156 mg, 0.37 mmol). The mixture was stirred at room temperature for 64 hours. The reaction was then quenched by the addition of saturated aqueous sodium sulphite (2 mL) and saturated aqueous sodium bicarbonate (2 mL). The mixture was stirred for 5 minutes. The mixture was diluted with water (10 mL) and dichloromethane (10 mL). The layers were separated and the aqueous further extracted with dichloromethane (2×10 mL). The combined organic extracts were washed with brine (10 mL), dried, filtered and concentrated to give the title compound 65 mg (77% yield) as a light orange powder. δ.sub.H NMR (500 MHz, DMSO) 9.83 (s, 1H), 9.06 (s, 1H), 8.08 (d, J=8.9 Hz, 1H), 7.72 (d, J=2.5 Hz, 1H), 7.18 (dd, J=8.9, 2.5 Hz, 1H), 3.85 (s, 3H). Tr(METCR1673)=1.10 min, (ES.sup.+) (M+H).sup.+ 233, 85%.
Step 4, Method 20: 2-{10-Methoxy-7-thia-2,5-diazatricyclo[6.4.0.0.SUP.2,6.]dodeca-1(12),3,5,8,10-pentaen-4-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0439] 10-Methoxy-7-thia-2,5-diazatricyclo[6.4.0.0.sup.26]dodeca-1(12),3,5,8,10-pentaene-4-carbaldehyde (65 mg, 0.28 mmol) and 2-aminoisonicotinonitrile (33 mg, 0.28 mmol) were suspended in methanol (5 mL). Acetic acid (0.5 mL) and methyl isocyanide (22 μL, 0.42 mmol) were added and the mixture stirred at room temperature for 18 hours. The reaction mixture was filtered, and collected solid dried under suction to give the title compound 28 mg (26% yield) as a yellow powder.
Example 1, Method 20: 2-{10-Methoxy-7-thia-2,5-diazatricyclo[6.4.0.0.SUP.2,6.]dodeca-1(12),3,5,8,10-pentaen-4-yl}-3-(methylamino)imidazo[1,2-a]pyridine-7-carbonitrile
[0440] δ.sub.H NMR (500 MHz, DMSO) 8.71 (s, 1H), 8.35 (d, J=7.1 Hz, 1H), 8.15 (s, 1H), 8.05 (d, J=8.9 Hz, 1H), 7.70 (d, J=2.5 Hz, 1H), 7.16 (dd, J=8.9, 2.5 Hz, 1H), 7.11 (dd, J=7.1, 1.6 Hz, 1H), 5.63 (q, J=5.8 Hz, 1H), 3.84 (s, 3H), 2.90 (d, J=5.9 Hz, 3H). Tr(MET-uHPLC-AB-101)=3.12 min, (ES.sup.+) (M+H).sup.+ 375.
[0441] The following examples were prepared using Method 20 described above:
TABLE-US-00020 TABLE 20 Mol. Ex. Structure Weight IUPAC Name LCMS data 1
Biology Examples
Q46 Radioligand Binding Assay
[0442] For radioligand binding assays (RBA) GST-Q46 protein was generated based on a previous publication (Scherzinger et al. Cell, Vol. 90, 549-558, Aug. 8, 1997). For experiments 33 μM GST-Q46 was incubated with 150 μg/mL thrombin in assay buffer (150 mM NaCl, 50 mM Tris pH 8.0) and 2 mM CaCl.sub.2 for 16 hours at 37° C. Aggregated Q46 was pelleted by centrifugation for 5 minutes at 13,000 rpm in a bench top centrifuge and re-dissolved in the same volume of assay buffer. Test compounds were prepared by titration in DMSO at 11 concentrations from 33 μM to 1 nM. For the RBA, Q46 protein aggregates and test compounds were pre-incubated in assay buffer for 20 minutes at room temperature, in 140 μL/well in a 96-well plate (pp, round bottom). Then, ligand was added in 10 μL/well and incubated for 60 minutes at 37° C. Final assay concentrations were 1 μM to 30 μM test compound, 5 μM Q46 protein (equivalent monomer concentration) and 10 nM ligand [.sup.3H.sub.3]MK-3328 (Harrision et al., ACS Med. Chem. Lett., 2 (2011), pp 498-502). Samples were transferred onto GF/B filter plates and washed 2× with 200 μL PBS using a Filtermate Harvester. After drying filter plates for 1 hour at 37° C., the back of the plates was sealed with foil and 30 μl/well scintillation fluid (Packard MicroScint 40) was added, incubated for incubated for 15 minutes in the dark and counted in a TopCount reader. For analysis, replicate data from independent assay plates were normalized towards 0% and 100% inhibition using control wells of vehicle (0% inhibition) and 3 μM unlabelled MK-3328 (100% inhibition). IC.sub.50 values were determined with a sigmoidal inhibition model with four variables (top, bottom, slope, IC.sub.50) in a global fit using the normalized replicate data.
[0443] RBA IC.sub.50 activity summary: <100 nM +++, 100-500 nM ++, >500 nM +
TABLE-US-00021 Structure IUPAC Name Activity
[0444] Various modifications, additions, substitutions, and variations to the illustrative examples set forth herein will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.