SELECTIVE BCRP/ABCG2 TRANSPORTER INHIBITORS AS AGENTS TO ABOLISH RESISTANCE TO ANTI-CANCER AGENTS

Abstract

A compound of formula (I):

##STR00001##

or pharmaceutically acceptable enantiomer, salt or solvate thereof, or a mixture thereof, the ring A, and the substituents Z, Y and R.sub.1 being as defined herein.

Claims

1. A compound of formula (I): ##STR00060## or pharmaceutically acceptable enantiomer, salt or solvate thereof, or a mixture thereof, in which: the ring A is unsubstituted or substituted in the 2, 3, 4, 5 position by one or two of F; Cl; Br; I; OR, with R Me, Et, Pr, i-Pr, n-Bu; O—CH.sub.2—(O—CH.sub.2CH.sub.2).sub.n—O—CH.sub.3, with n 3, 4, 5, 6, Z is ##STR00061## or —CH.sub.2—, Y═—OH; —OMe;-OEt; —OPr; —NH.sub.2; —NHMe; —N(Me).sub.2; —N(Me)OCH.sub.3; —NH—(CH.sub.2).sub.2-(3-indolyl); —NH(CH.sub.2).sub.2-3-((5-hydroxy)indolyl); —NH—CH(R.sub.3)—COR.sub.2, with R.sub.2 selected from: OH; —OMe;-OEt; —OPr; —NH.sub.2; —NHMe; —N(Me).sub.2; —N(Me)OCH.sub.3; 3-(5-methoxy)indolyl; —NH—(CH.sub.2).sub.2-(3-indolyl); —NH(CH.sub.2).sub.2-3-((5-hydroxy)indolyl); —NH(CH.sub.2).sub.2-3-((5-methoxy)indolyl) ##STR00062## in formula (I) and R.sub.3 of the substituent —NH—CH(R.sub.3)—COR.sub.2 of Y are independently selected from: H or ##STR00063## with the exception of compounds with simultaneous Br in the 4-position of ring A, R.sub.1═CH(CH.sub.3).sub.2 or CH.sub.2CH(CH.sub.3).sub.2 or CH(CH.sub.3)CH.sub.2CH.sub.3, Z= ##STR00064## and Y═—OH or —OMe.

2. The compound according to claim 1, wherein the ring A is substituted in position 2, 3, 4, 5 by one or two Br and Y═—OH; —OMe; —NH—(CH.sub.2).sub.2-(3-indolyl); —NH(CH.sub.2).sub.2-3-((5-hydroxy)indolyl); —NH—CH(R.sub.3)—COR.sub.2, R.sub.1, R.sub.2 and R.sub.3 being as defined in claim 1.

3. The compound according to claim 1, wherein Y is —NH—(CH.sub.2).sub.2-(3-indolyl) or —NH(CH.sub.2).sub.2-3-((5-hydroxy)indolyl) with the proviso that: ##STR00065##

4. The compound according to claim 1 selected from: methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucinate; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-leucinate; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-valinate; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalaninate; methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalaninate; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-tryptophanate; methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-tryptophanate; methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-D-tryptophanate; (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucine; (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalanine; (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalanine; (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-D-tryptophan; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-valinate; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-leucinate; methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-valinate; methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-leucinate; (S)-5-((2-bromobenzyl)oxy)-N-(1-((2-(5-hydroxy-1H-indol-3-yl)ethyl)amino)-1-oxo-3-phenylpropan-2-yl)-4-oxo-4H-chromene-2-carboxamide; (S)—N-(1-((2-(1H-indol-3-yl)ethyl)amino)-1-oxo-3-phenylpropan-2-yl)-5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxamide; and (R)—N-(1-((2-(1H-indol-3-yl)ethyl)amino)-3-(1H-indol-3-yl)-1-oxopropan-2-yl)-5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxamide.

5. A process for obtaining the compounds according to claim 1, wherein it comprises the steps: (a) an alkylating compound of the formula ##STR00066## wherein the ring A is as defined in claim 1, and X is a halogen selected from F, Cl, Br and I, is reacted on 2,6-dihydroxyacetophenone of the formula ##STR00067## at the reflux temperature of acetone and in acetone to give the intermediate of formula ##STR00068## (b) the intermediate obtained in step (a) is reacted with diethyl oxalate of formula ##STR00069## at a temperature of 0° C.-50° C. and in a mixture of tetrahydrofuran (THF)/ethanol (1:1) to give the intermediate of formula ##STR00070## (c) the intermediate obtained in step (b) is reacted by a hydrolysis reaction of the ester function at a temperature of 50° C., in an acidic or basic medium, in a THF/ethanol/water solvent (3:1:1.5) in order to obtain the intermediate of formula ##STR00071## (d) the intermediate obtained in step (c) is reacted with a coupling compound of the formula ##STR00072## R.sub.1, Z and Y being as defined in claim 1, at room temperature in anhydrous DMF to form an amide bond to give the compound of formula (I).

6. A method for treating breast cancer, the method comprising: administering to a patient in need thereof an effective amount of a compound of formula (I) for inhibition of a multi-drug resistance protein of the breast cancer, the multi-drug resistance protein including Breast Cancer Resistance Protein BCRP/ABCG2, wherein the compound of formula (I) is: ##STR00073## or pharmaceutically acceptable enantiomer, salt or solvate thereof, or a mixture thereof, in which: the ring A is unsubstituted or substituted in the 2, 3, 4, 5 position by one or two of F; Cl; Br; I; OR, with R=Me, Et, Pr, i-Pr, n-Bu; O—CH.sub.2—(O—CH.sub.2CH.sub.2).sub.n—O—CH.sub.3, with n=3, 4, 5, 6, Z is ##STR00074## or —CH.sub.2—, Y═—OH; —OMe;-OEt; —OPr; —NH.sub.2; —NHMe; —N(Me).sub.2; —N(Me)OCH.sub.3; —NH—(CH.sub.2).sub.2-(3-indolyl); —NH(CH.sub.2).sub.2-3-((5-hydroxy)indolyl); —NH—CH(R.sub.3)—COR.sub.2, with R.sub.2 selected from: OH; —OMe;-OEt; —OPr; —NH.sub.2; —NHMe; —N(Me).sub.2; —N(Me)OCH.sub.3; 3-(5-methoxy)indolyl; —NH—(CH.sub.2).sub.2-(3-indolyl); —NH(CH.sub.2).sub.2-3-((5-hydroxy)indolyl); —NH(CH.sub.2).sub.2-3-((5-methoxy)indolyl) ##STR00075## in formula (I) and R.sub.3 of the substituent —NH—CH(R.sub.3)—COR.sub.2 of Y are independently selected from: H or ##STR00076##

7. The method according to claim 6, wherein the ring A is substituted in the 2-, 3-, 4-, 5-position by one or two Br and Y═—OH; —OMe; —NH—(CH.sub.2).sub.2-(3-indolyl); —NH(CH.sub.2).sub.2-3-((5-hydroxy)indolyl); —NH—CH(R.sub.3)—COR.sub.2, R.sub.1, R.sub.2 and R.sub.3 being as defined in claim 6.

8. The method according to claim 6, wherein Y is —NH—(CH.sub.2).sub.2-(3-indolyl) or —NH(CH.sub.2).sub.2-3-((5-hydroxy)indolyl) with the proviso that: ##STR00077##

9. The method according to claim 6, selected from: methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucinate; methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucinate; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-leucinate; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-valinate; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalaninate; methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalaninate; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-tryptophanate; methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-tryptophanate; methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-D-tryptophanate; (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucine; (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalanine; (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalanine; (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-D-tryptophan; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-valinate; methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-leucinate; methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-valinate; methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-leucinate; (S)-5-((2-bromobenzyl)oxy)-N-(1-((2-(5-hydroxy-1H-indol-3-yl)ethyl)amino)-1-oxo-3-phenylpropan-2-yl)-4-oxo-4H-chromene-2-carboxamide; (S)—N-(1-((2-(1H-indol-3-yl)ethyl)amino)-1-oxo-3-phenylpropan-2-yl)-5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxamide, and (R)—N-(1-((2-(1H-indol-3-yl)ethyl)amino)-3-(1H-indol-3-yl)-1-oxopropan-2-yl)-5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxamide.

10. A pharmaceutical composition comprising: at least one pharmaceutically acceptable active agent; and at least one compound according to one claim 1.

11. The pharmaceutical composition of claim 10, wherein the pharmaceutically acceptable active agent is selected from anti-cancer agents, intestinal anti-inflammatory agents, hypocholesteremic agents, anti-dyslipidemic agents and kinase inhibitors.

Description

EXAMPLES 1 TO 20

Series 1

[0093] ##STR00021##

Note: In the following protocols, “molecule number+a” refers to when the bromine is in position 2 of the aromatic ring while “molecule number+b” refers to when the bromine is in position 4 of the aromatic ring.

General Procedure A:

[0094] To a solution of 2,6-dihydroxyacetophenone 1 (1 equiv) in acetone (6 mL/mmol) was simultaneously added K.sub.2CO.sub.3 (3 equiv) and tetra-n-butylammonium bromide (0.4 equiv) previously homogenised together.

[0095] The solution was refluxed for 30-60 min before the dropwise addition of the corresponding bromobenzyl bromide (1 equiv) in acetone (15 mL/mmol).

[0096] The solution was then refluxed for 4-5 hours and monitored by TLC (ethyl acetate/cyclohexane 3:7). The solution was poured into water and extracted with ethyl acetate. The organic phases were collected and washed with water and brine before being dried over magnesium sulphate, filtered and evaporated under vacuum.

General Procedure B:

[0097] To a solution of 2 (1 equiv) in anhydrous THF (10 mL/mmol) was added a solution of sodium ethanolate generated in situ from sodium (6 equiv) in anhydrous ethanol (15 mL/mmol) at 0° C. and under an inert atmosphere.

[0098] The solution was stirred for 30 min at room temperature and diethyl oxalate (4 equiv) was added dropwise to the solution. The solution was then heated to 50° C. until precipitation and then refluxed for 2 hours. The reaction was monitored by TLC (cyclohexane/ethyl acetate 1:1).

[0099] Then a few drops of concentrated hydrochloric acid (37%) were added to the solution until the precipitate formed became white.

[0100] The solution was refluxed for 1 hour before being cooled to room temperature. After concentration under vacuum, the solution was poured into water and extracted with ethyl acetate. The organic phases were collected and washed with water and brine before being dried over magnesium sulphate, filtered and evaporated under vacuum.

General Operating Procedure C

[0101] To a solution of 3 (1 equiv) in THF (25 mL/mmol) and ethanol (8 mL/mmol) was added a solution of K.sub.2CO.sub.3 (1.3 equiv) in water (12 mL/mmol).

[0102] The solution was heated to 50° C. for 4 hours and monitored by TLC (ethyl acetate/cyclohexane 1:1). The solution was concentrated under vacuum and then poured into basic water (K.sub.2CO.sub.3 20%) and washed with ethyl acetate. The basic aqueous phase was acidified with concentrated hydrochloric acid (37%) and extracted with ethyl acetate.

[0103] The organic phases were then collected and washed with water and brine before being dried over magnesium sulphate, filtered and evaporated.

General Operating Procedure D:

[0104] To a solution of carboxylic acid derivative 4 (1 equiv) in anhydrous dimethylformamide (DMF) (20 mL/mmol) was added 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminium tetrafluoroborate (TBTU) (2 equiv). The solution was stirred for 30 minutes at room temperature.

[0105] Next, a solution of amino acid derivative (2 equiv) in DMF (10 mL/mmol) in the presence of N, N-diisopropylethylamine (DIEA) (4 equiv) was added carefully to the previous one. The reaction was stirred for 12 or 24 hours at room temperature and monitored by TLC (ethyl acetate/cyclohexane 1:1). The solution was concentrated under vacuum and then poured into acidified water (1M HCl) and extracted with ethyl acetate.

[0106] The organic phases were collected and washed with NaHCO.sub.3 solution (20%), water and brine before being dried over magnesium sulphate, filtered and concentrated under vacuum.

General Operating Mode E

[0107] To a solution of ester derivative 5 (1 equiv) in THF (25 mL/mmol) and methanol (10 mL/mmol) was added a solution of LiOH (1.5 equiv) in H.sub.2O (10 mL/mmol). The reaction was stirred for 2 hours at room temperature and monitored by TLC (ethyl acetate/cyclohexane 1:1).

[0108] The solution was poured into basified water (20% NaHCO.sub.3) and washed with ethyl acetate. The aqueous phase was acidified with concentrated hydrochloric acid (37%) and extracted with ethyl acetate.

[0109] The organic phases were then collected and washed with brine before being dried over magnesium sulphate, filtered and concentrated under vacuum.

EXAMPLE 1

Preparation of 1-(2-((2-bromobenzyl)oxy)-6-hydroxyphenyl)ethan-1-one (2a)

[0110] ##STR00022##

[0111] The crude was prepared according to general procedure A starting from 1 (1.500 g, 9.86 mmol) and purified by recrystallisation in methanol or ethyl acetate to give 2a (2.583 g, 82%). C.sub.15H.sub.13BrO.sub.3.

[0112] .sup.1H NMR (400 MHz, DMSO) δ 11.69 (s, 1H), 7.71 (dd, J=8.0, 1.1 Hz, 1H), 7.61 (dd, J=7.6, 1.6 Hz, 1H), 7.46 (td, J=7.5, 1.2 Hz, 1H), 7.39-7.29 (m, 2H), 6.67 (dd, J=8.4, 0.5 Hz, 1H), 6.56 (dd, J=8.3, 0.7 Hz, 1H), 5.19 (s, 2H), 2.47 (s, 3H).

[0113] .sup.13C NMR (101 MHz, DMSO) δ 203.38, 159.60, 157.95, 135.31, 133.90, 132.72, 130.64, 130.41, 128.00, 123.04, 114.62, 109.83, 103.19, 70.02, 32.86

[0114] m. p.: 75.5-77.4° C.

[0115] MS (ESI) m/z 321 (.sup.79Br), 323 (.sup.81Br) [M+H].sup.+, 319 (.sup.79Br), 321 (.sup.81Br) [M−H].sup.+.

EXAMPLE 2

Preparation of 1-(2-((4-bromobenzyl)oxy)-6-hydroxyphenyl)ethan-1-one (2b)

[0116] ##STR00023##

[0117] The crude was prepared according to general procedure A starting from 1 (1.500 g, 9.86 mmol) and purified by recrystallisation in ethyl acetate to give 2b (2.321, 73%). C.sub.15H.sub.13BrO.sub.3.

[0118] .sup.1H NMR (400 MHz, DMSO) δ 11.64 (s, 1H), 7.62-7.58 (m, 2H), 7.45-7.41 (m, 2H), 7.30 (t, J=8.3 Hz, 1H), 6.62 (dd, J=8.4, 0.5 Hz, 1H), 6.52 (dd, J=8.3, 0.7 Hz, 1H), 5.14 (s, 2H), 2.48 (s, 3H)

[0119] .sup.13C NMR (101 MHz, DMSO) δ 203.43, 159.52, 157.94, 135.96, 133.77, 131.41, 129.98, 121.15, 114.75, 109.63, 103.41, 69.30, 33.04

[0120] m. p.: 114.8-116.8° C.

[0121] MS (ESI) m/z 320 (.sup.79Br), 322 (.sup.81Br) [M].

EXAMPLE 3

Preparation of ethyl 5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxylate (3a)

[0122] ##STR00024##

[0123] The crude was prepared according to general procedure B starting from 2a (2.583 g, 8.04 mmol) and purified by recrystallisation in methanol or ethyl acetate to give 3a (2.478, 76%). C.sub.19H.sub.15BrO.sub.5.

[0124] .sup.1H NMR (400 MHz, DMSO) δ 8.11 (dd, J=7.7, 1.4 Hz, 1H), 7.79 (t, J=8.4 Hz, 1H), 7.68 (dd, J=8.0, 1.0 Hz, 1H), 7.51 (td, J=7.6, 1.1 Hz, 1H), 7.33 (td, J=7.8, 1.7 Hz, 1H), 7.30-7.25 (m, 1H), 7.18-7.13 (m, 1H), 6.79 (s, 1H), 5.23 (s, 2H), 4.40 (q, J=7.1 Hz, 2H), 1.36 (t, J=7.1 Hz, 3H)

[0125] .sup.13C NMR (101 MHz, DMSO) δ 176.40, 172.49, 160.01, 158.25, 157.43, 150.24, 135.70, 135.44, 132.17, 129.57, 129.12, 127.85, 121.05, 115.43, 114.62, 110.78, 108.85, 69.72, 62.61, 13.87

[0126] m. p.: 155.3-157.1° C.

[0127] MS (ESI) m/z 403 (.sup.79Br), 405 (.sup.81Br) [M−H].sup.+.

EXAMPLE 4

Preparation of ethyl 5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxylate (3b)

[0128] ##STR00025##

[0129] The crude was prepared according to general procedure B starting from 2b (1.718 g, 5.35 mmol) and purified by recrystallisation in methanol or ethyl acetate to give 3b (1.516, 70%). C.sub.19H.sub.15BrO.sub.5.

[0130] .sup.1H NMR (400 MHz, DMSO) δ 7.74 (t, J=8.4 Hz, 1H), 7.64-7.56 (m, 4H), 7.25-7.21 (m, 1H), 7.13-7.08 (m, 1H), 6.77 (s, 1H), 5.24 (s, 2H), 4.38 (q, J=7.1 Hz, 2H), 1.34 (t, J=7.1 Hz, 3H).

[0131] .sup.13C NMR (101 MHz, DMSO) δ 176.39, 160.01, 157.70, 157.23, 150.19, 136.23, 135.29, 131.21, 128.90, 120.61, 115.43, 114.68, 110.54, 109.02, 69.22, 62.59, 13.87

[0132] m. p.: 148.0-149.4° C.

[0133] MS (ESI) m/z 402 (.sup.79Br), 404 (.sup.81Br) [M].sup.+.

EXAMPLE 5

Preparation of 5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxylic Acid (4a)

[0134] ##STR00026##

[0135] The crude was prepared according to general procedure C starting from 3a (1.000 g, 2.48 mmol) and purified by trituration in methanol and washed with diethyl ether to give 4a (0.777, 84%). The desired product can also be obtained crystalline by recrystallising in methanol. C.sub.17H.sub.11BrO.sub.5.

[0136] .sup.1H NMR (400 MHz, DMSO) δ 8.14 (dd, J=7.7, 1.1 Hz, 1H), 7.77 (t, J=8.4 Hz, 1H), 7.68 (dd, J=8.0, 0.9 Hz, 1H), 7.51 (td, J=7.6, 0.9 Hz, 1H), 7.32 (td, J=7.8, 1.5 Hz, 1H), 7.26 (d, J=8.1 Hz, 1H), 7.13 (d, J=8.3 Hz, 1H), 6.74 (s, 1H), 5.23 (s, 2H).

[0137] .sup.13C NMR (101 MHz, DMSO) δ 176.70, 161.44, 157.42, 157.36, 151.31, 135.75, 135.24, 132.13, 129.52, 129.13, 127.82, 121.01, 115.17, 114.63, 110.80, 108.71, 69.71

[0138] m. p.: 244.3° C.

[0139] MS (ESI) m/z 373 (.sup.79Br), 375 (.sup.81Br) [M−H].sup.−.

EXAMPLE 6

Preparation of 5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxylic Acid (4b)

[0140] ##STR00027##

[0141] The crude was prepared according to general procedure C starting from 3b (1.586 g, 3.93 mmol) and purified by trituration in methanol and washed with diethyl ether to give 4b (1.259, 85%). The desired product can be crystallised in methanol to give white crystals. C.sub.17H.sub.11BrO.sub.5.

[0142] .sup.1H NMR (400 MHz, DMSO) δ 7.76 (t, J=8.4 Hz, 1H), 7.66-7.59 (m, 4H), 7.24 (dd, J=8.4, 0.7 Hz, 1H), 7.14-7.10 (m, 1H), 6.76 (s, 1H), 5.27 (s, 2H)

[0143] .sup.13C NMR (101 MHz, DMSO) δ 176.69, 161.44, 157.69, 157.35, 151.15, 136.27, 135.14, 131.20, 128.89, 120.58, 115.21, 114.69, 110.58, 108.93, 69.23

[0144] m. p.: 204.6-205.3° C.

[0145] MS (ESI) m/z 374 (.sup.79Br), 376 (.sup.81Br) [M].sup.+.

EXAMPLE 7

Preparation of methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucinate (5a)

[0146] ##STR00028##

[0147] The crude was prepared according to general procedure D starting from 4a (511 mg, 1.36 mmol) and isoleucine methyl ester hydrochloride (0.485 g, 2.72 mmol) and purified by recrystallisation in methanol to give 5a (0.352 g, 51%). C.sub.24H.sub.24BrNO.sub.6.

[0148] .sup.1H NMR (400 MHz, DMSO) δ 9.23 (d, J=7.7 Hz, 1H), 8.14 (d, J=7.4 Hz, 1H), 7.82 (t, J=8.4 Hz, 1H), 7.69 (d, J=7.9 Hz, 1H), 7.52 (t, J=7.4 Hz, 1H), 7.40 (d, J=8.4 Hz, 1H), 7.33 (t, J=7.3 Hz, 1H), 7.17 (d, J=8.3 Hz, 1H), 6.74 (s, 1H), 5.25 (s, 2H), 4.39 (t, J=7.7 Hz, 1H), 3.70 (s, 3H), 2.10-1.99 (m, 1H), 1.60-1.48 (m, J=11.6, 5.8 Hz, 1H), 1.33-1.23 (m, 1H), 0.97-0.86 (m, 6H)

[0149] .sup.13C NMR (101 MHz, DMSO) δ 176.44, 171.41, 159.61, 157.38, 157.05, 152.97, 135.76, 135.11, 132.17, 129.56, 129.14, 127.85, 121.04, 114.49, 112.75, 111.09, 108.81, 69.70, 57.26, 51.90, 35.48, 25.09, 15.37, 10.77

[0150] m. p.: 123.1-125.7° C.

[0151] HRMS (ESI/QTOF): [0152] calculated for C.sub.24H.sub.25BrNO.sub.6 (M+H.sup.+): 502.0865, [0153] found: 502.0860.

[0154] Purity (HPLC)>95%.

EXAMPLE 8

Preparation of methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucinate (5b)

[0155] ##STR00029##

[0156] The crude was prepared according to general procedure D starting from 4b (300 mg, 0.80 mmol) and L-isoleucine methyl ester hydrochloride (290 mg, 1.60 mmol) and purified by recrystallisation in methanol to afford 5b (318 mg, 79%). C.sub.24H.sub.24BrNO.sub.6.

[0157] .sup.1H NMR (400 MHz, DMSO) δ 9.17 (d, J=7.9 Hz, 1H), 7.77 (t, J=8.4 Hz, 1H), 7.64-7.56 (m, 4H), 7.34 (dd, J=8.5, 0.7 Hz, 1H), 7.12 (d, J=8.1 Hz, 1H), 6.70 (s, 1H), 5.25 (s, 2H), 4.37 (t, J=7.7 Hz, 1H), 3.68 (s, 3H), 2.07-1.96 (m, 1H), 1.58-1.45 (m, 1H), 1.32-1.19 (m, 1H), 0.95-0.84 (m, 6H)

[0158] .sup.13C NMR (101 MHz, DMSO) δ 176.41, 171.40, 159.62, 157.63, 157.04, 152.91, 136.29, 134.95, 131.21, 128.92, 120.59, 114.54, 112.73, 110.86, 108.99, 69.19, 57.24, 51.88, 35.48, 25.09, 15.37, 10.77

EXAMPLE 9

Preparation of methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-leucinate (5c)

[0159] ##STR00030##

[0160] The crude was prepared according to general procedure D starting from 4a (500 mg, 1.33 mmol) and L-leucine methyl ester hydrochloride (0.483 g, 2.66 mmol) and purified by recrystallisation in methanol to give 5c (234 mg, 35%). C.sub.24H.sub.24BrNO.sub.6.

[0161] .sup.1H NMR (400 MHz, CDCl.sub.3) δ 8.13 (d, J=7.4 Hz, 1H), 7.57 (t, J=8.3 Hz, 1H), 7.48 (d, J=7.9 Hz, 1H), 7.38 (t, J=7.5 Hz, 1H), 7.18-7.05 (m, 3H), 6.98 (s, 1H), 6.90 (d, J=8.3 Hz, 1H), 5.18 (s, 2H), 4.82-4.73 (m, 1H), 3.74 (s, 3H), 1.80-1.60 (m, 3H), 0.99-0.87 (m, 6H).

[0162] .sup.13C NMR (101 MHz, CDCl.sub.3) δ 177.52, 172.93, 159.05, 158.46, 157.33, 152.34, 135.55, 134.74, 132.10, 129.07, 128.79, 128.12, 120.82, 115.42, 114.21, 110.63, 108.66, 70.38, 52.73, 51.14, 41.81, 25.02, 22.82, 22.05

[0163] m. p.: 60.3-60.4° C.

[0164] HRMS (ESI/QTOF): [0165] calculated for C.sub.24H.sub.25BrNO.sub.6 (M+H.sup.+): 502.0865, [0166] found: 502.0865.

[0167] Purity (HPLC)>98%.

EXAMPLE 10

Preparation of methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-valinate (5d)

[0168] ##STR00031##

[0169] The crude was prepared according to general procedure D starting from 4a (0.200 g, 0.53 mmol) and L-valine methyl ester hydrochloride (0.179 g, 1.07 mmol) and purified by recrystallisation in methanol to afford 5d (0.126 g, 48%). C.sub.23H.sub.22BrNO.sub.6.

[0170] .sup.1H NMR (400 MHz, DMSO) δ 9.20 (d, J=7.8 Hz, 1H), 8.12 (d, J=7.4 Hz, 1H), 7.82 (t, J=8.4 Hz, 1H), 7.69 (d, J=7.8 Hz, 1H), 7.51 (t, J=7.5 Hz, 1H), 7.39 (d, J=8.4 Hz, 1H), 7.33 (t, J=7.4 Hz, 1H), 7.16 (d, J=8.3 Hz, 1H), 6.74 (s, 1H), 5.24 (s, 2H), 4.33 (t, J=7.7 Hz, 1H), 3.70 (s, 3H), 2.32-2.19 (m, 1H), 1.06-0.92 (m, 6H)

[0171] .sup.13C NMR (101 MHz, DMSO) δ 176.42, 171.34, 159.69, 157.41, 157.07, 153.03, 135.76, 135.09, 132.17, 129.57, 129.18, 127.84, 121.07, 114.53, 112.74, 111.10, 108.88, 69.76, 58.56, 51.90, 29.46, 19.04, 18.95

[0172] m. p.: 127.0-128.2° C.

[0173] HRMS (ESI/QTOF): [0174] calculated for C.sub.23H.sub.23BrNO.sub.6 (M+H.sup.+): 488.0709, [0175] found: 488.0719.

[0176] Purity (HPLC)>98%.

EXAMPLE 11

Preparation of methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalaninate (5e)

[0177] ##STR00032##

[0178] The crude was prepared according to general procedure D starting from 4a (0.194 g, 0.52 mmol) and L-phenylalanine methyl ester hydrochloride (0.223 g, 1.04 mmol) and purified by precipitation in diethyl ether and cyclohexane to give 5e (0.187 g, 70%). C.sub.27H.sub.22BrNO.sub.6.

[0179] .sup.1H NMR (400 MHz, DMSO) δ 9.47 (s, 1H), 8.13 (dd, J=7.7, 1.5 Hz, 1H), 7.82 (t, J=8.4 Hz, 1H), 7.68 (dd, J=8.0, 1.1 Hz, 1H), 7.51 (td, J=7.6, 1.1 Hz, 1H), 7.35-7.27 (m, 6H), 7.25-7.19 (m, 1H), 7.16 (d, J=8.0 Hz, 1H), 6.64 (s, 1H), 5.24 (s, 2H), 4.77-4.71 (m, 1H), 3.69 (s, 3H), 3.26 (dd, J=13.8, 5.4 Hz, 1H), 3.21-3.13 (m, 1H).

[0180] .sup.13C NMR (101 MHz, DMSO) δ 176.33, 171.26, 159.21, 157.42, 156.95, 152.77, 137.22, 135.74, 135.24, 132.15, 129.54, 129.11, 129.06, 128.31, 127.84, 126.62, 121.01, 114.43, 112.57, 110.82, 108.85, 69.69, 54.13, 52.20, 35.93, 30.67

[0181] m. p.: 145.5-147.5° C.

[0182] HRMS (ESI/QTOF) [0183] calculated for C.sub.27H.sub.23BrNO.sub.6 (M+H.sup.+): 536.0709, [0184] found: 536.0711.

[0185] Purity (HPLC)>97%.

EXAMPLE 12

Preparation of methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalaninate (5f)

[0186] ##STR00033##

[0187] The crude was prepared according to general procedure D starting from 4b (0.472 g, 1.26 mmol) and L-phenylalanine methyl ester hydrochloride (0.453 g, 2.52 mmol) and purified by recrystallisation in methanol to give 5f (0.551 g, 90%). C.sub.27H.sub.22BrNO.sub.6.

[0188] .sup.1H NMR (400 MHz, DMSO) δ 9.43 (d, J=7.9 Hz, 1H), 7.79 (t, J=8.4 Hz, 1H), 7.68-7.54 (m, 4H), 7.30 (d, J=12.6 Hz, 5H), 7.23 (d, J=6.1 Hz, 1H), 7.13 (d, J=8.3 Hz, 1H), 6.63 (s, 1H), 5.26 (s, 2H), 4.73 (dd, J=13.5, 9.1 Hz, 1H), 3.68 (s, 3H), 3.26 (dd, J=13.8, 5.2 Hz, 1H), 3.16 (dd, J=13.6, 10.3 Hz, 1H).

[0189] .sup.13C NMR (101 MHz, DMSO) δ 176.31, 171.22, 159.22, 157.68, 156.94, 152.71, 137.20, 136.26, 135.08, 131.20, 129.05, 128.91, 128.31, 126.62, 120.59, 114.50, 112.56, 110.60, 109.06, 69.21, 54.10, 52.20, 35.93

[0190] Decomposition point: 153.1° C.

[0191] HRMS (ESI/QTOF) [0192] calculated for C.sub.27H.sub.23BrNO.sub.6 (M+H.sup.+): 536.0709, [0193] found: 536.0704.

[0194] Purity (HPLC)>96%.

EXAMPLE 13

Preparation of methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-tryptophanate (5 g)

[0195] ##STR00034##

[0196] The crude was prepared according to general procedure D starting from 4a (0.100 g, 0.27 mmol) and L-tryptophan methyl ester hydrochloride (0.136 g, 0.53 mmol) and purified by recrystallisation in methanol to give 5 g (0.043 g, 28%). C.sub.29H.sub.23BrN.sub.2O.sub.6.

[0197] .sup.1H NMR (400 MHz, DMSO) δ 10.89 (s, 2H), 9.36 (d, J=7.8 Hz, 2H), 8.12 (d, J=7.7 Hz, 2H), 7.83 (t, J=8.4 Hz, 2H), 7.69 (dd, J=8.0, 0.9 Hz, 2H), 7.62 (d, J=7.8 Hz, 2H), 7.51 (td, J=7.5, 0.9 Hz, 2H), 7.39-7.28 (m, 6H), 7.25 (d, J=2.2 Hz, 2H), 7.17 (d, J=8.3 Hz, 2H), 7.07 (td, J=7.7, 0.9 Hz, 2H), 6.98 (t, J=7.4 Hz, 2H), 6.65 (s, 2H), 5.24 (s, 4H), 4.80-4.70 (m, 2H), 3.69 (s, 7H)

[0198] .sup.13C NMR (101 MHz, DMSO) δ 176.36, 171.52, 159.18, 157.43, 156.95, 152.81, 136.09, 135.74, 135.21, 132.17, 129.57, 129.15, 127.85, 127.03, 123.79, 121.05, 121.02, 118.44, 118.04, 114.43, 112.55, 111.48, 110.83, 109.47, 108.89, 69.73, 53.80, 52.19, 26.38 Two proton signals below the water peak.

[0199] m. p.: 250-252.8° C.

[0200] HRMS (ESI/QTOF): [0201] calculated for C.sub.29H.sub.24BrN.sub.2O.sub.6 (M+H.sup.+): 575.0818, [0202] found: 575.0821.

[0203] Purity (HPLC)>99%.

EXAMPLE 14

Preparation of methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-tryptophanate (5h)

[0204] ##STR00035##

[0205] The crude was prepared according to general procedure D starting from 4b (0.100 g, 0.27 mmol) and L-tryptophan methyl ester hydrochloride (0.136 g, 0.533 mmol) and purified by recrystallisation in methanol to afford 5h (0.126 g, 82%). C.sub.29H.sub.23BrN.sub.2O.sub.6.

[0206] .sup.1H NMR (400 MHz, DMSO) δ 10.90 (s, 1H), 9.34 (d, J=7.8 Hz, 1H), 7.79 (t, J=8.4 Hz, 1H), 7.69-7.52 (m, 5H), 7.35 (d, J=8.1 Hz, 1H), 7.29 (d, J=8.1 Hz, 1H) 7.25 (d, J=2.2 Hz, 1H), 7.12 (d, J=8.3 Hz, 1H), 7.10-7.03 (m, 1H), 7.02-6.94 (m, 1H), 6.63 (s, 1H), 5.25 (s, 2H), 4.80-4.69 (m, 1H), 3.68 (s, 3H)

[0207] .sup.13C NMR (101 MHz, DMSO) δ 176.34, 171.50, 159.19, 157.67, 156.92, 152.76, 136.25, 136.10, 135.04, 131.20, 128.92, 127.03, 123.78, 121.02, 120.59, 118.44, 118.04, 114.48, 112.54, 111.48, 110.61, 109.47, 109.06, 69.23, 53.79, 52.18, 26.39 Two proton signals below the water peak.

[0208] m. p.: 235.3-236.2° C.

[0209] HRMS (ESI/QTOF):

[0210] calculated for C.sub.29H.sub.24BrN.sub.2O.sub.6 (M+H.sup.+): 575.0818.

[0211] found: 575.0807.

[0212] Purity (HPLC)>99%.

EXAMPLE 15

Preparation of methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-D-tryptophanate (5i)

[0213] ##STR00036##

[0214] The crude was prepared according to general procedure D starting from 4b (0.300 g, 0.80 mmol) and D-tryptophan methyl ester hydrochloride (0.408 g, 1.60 mmol) and purified by precipitation in ethyl acetate and cyclohexane to afford 5i (0.375 g, 81%). C.sub.29H.sub.23BrN.sub.2O.sub.6.

[0215] .sup.1H NMR (400 MHz, DMSO) δ 10.90 (s, 1H), 9.34 (d, J=7.8 Hz, 1H), 7.79 (t, J=8.4 Hz, 1H), 7.66-7.57 (m, 5H), 7.35 (d, J=8.1 Hz, 1H), 7.29 (d, J=8.3 Hz, 1H), 7.25 (d, J=2.1 Hz, 1H) 7.12 (d, J=8.3 Hz, 1H), 7.07 (t, J=7.2 Hz, 1H), 6.98 (t, J=7.4 Hz, 1H), 6.63 (s, 1H), 5.25 (s, 2H), 4.79-4.70 (m, 1H), 3.69 (s, 3H), 3.43-3.38 (m, 1H), 3.33-3.27 (m, 1H)

[0216] .sup.13C NMR (101 MHz, DMSO) δ 176.33, 171.51, 159.18, 157.67, 156.93, 152.75, 136.26, 136.10, 135.04, 131.20, 128.91, 127.03, 123.78, 121.01, 120.59, 118.43, 118.04, 114.48, 112.54, 111.48, 110.60, 109.47, 109.04, 69.21, 53.79, 52.18, 26.38

[0217] m. p.: 236.2-237.9° C.

[0218] HRMS (ESI/QTOF): [0219] calculated for C.sub.29H.sub.24BrN.sub.2O.sub.6 (M+H.sup.+): 575.0818, [0220] found: 575.0822.

[0221] Purity (HPLC)>99%.

EXAMPLE 16

Preparation of (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucine (6a)

[0222] ##STR00037##

[0223] The crude was prepared according to general procedure E starting from 5a (0.256 g, 0.51 mmol) and purified by recrystallisation in methanol to give 6a (0.114 g, 46%). C.sub.23H.sub.22BrNO.sub.6.

[0224] .sup.1H NMR (400 MHz, DMSO) δ 8.99 (d, J=8.1 Hz, 1H), 8.14 (d, J=7.5 Hz, 1H), 7.82 (t, J=8.4 Hz, 1H), 7.69 (dd, J=7.9, 0.8 Hz, 1H), 7.52 (td, J=7.6, 0.8 Hz, 1H), 7.41 (d, J=8.2 Hz, 1H), 7.33 (td, J=7.8, 1.5 Hz, 1H), 7.17 (d, J=8.2 Hz, 1H), 6.73 (s, 1H), 5.25 (s, 2H), 4.39-4.31 (m, 1H), 2.08-1.98 (m, 1H), 1.61-1.48 (m, 1H), 1.35-1.23 (m, 1H), 0.97 (d, J=6.8 Hz, 3H), 0.90 (t, J=7.4 Hz, 3H).

[0225] .sup.13C NMR (101 MHz, DMSO) δ 176.46, 172.23, 159.43, 157.39, 157.06, 153.18, 135.76, 135.07, 132.16, 129.57, 129.16, 127.84, 121.06, 114.49, 112.64, 111.12, 108.84, 69.73, 57.21, 35.62, 25.04, 15.52, 10.96

[0226] m. p.: 242.8-243.7° C.

[0227] HRMS (ESI/QTOF): [0228] calculated for C.sub.23H.sub.23BrNO.sub.6 (M+H.sup.+): 488.0709, [0229] found: 488.0712.

[0230] Purity (HPLC)>98%.

EXAMPLE 17

Preparation of (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonyl)-L-alloisoleucine (6b)

[0231] ##STR00038##

[0232] The crude was prepared according to general procedure E starting from 5b (671 mg, 0.51 mmol) and purified by recrystallisation in methanol to give 6b (419 mg, 64%). C.sub.23H.sub.22BrNO.sub.6.

[0233] .sup.1H NMR (400 MHz, DMSO) δ 12.91 (s, 1H), 8.98 (d, J=8.1 Hz, 1H), 7.78 (t, J=8.4 Hz, 1H), 7.67-7.57 (m, 4H), 7.37 (dd, J=8.5, 0.6 Hz, 1H), 7.13 (d, J=8.2 Hz, 1H) 6.72 (s, 1H), 5.26 (s, 2H), 4.40-4.29 (m, 1H), 2.07-1.96 (m, 1H), 1.61-1.45 (m, 1H), 1.38-1.20 (m, 1H), 0.96 (d, J=6.8 Hz, 3H), 0.90 (t, J=7.4 Hz, 3H). (ERO1-94)

[0234] .sup.13C NMR (101 MHz, DMSO) δ 176.44, 172.23, 159.44, 157.63, 157.04, 153.12, 136.28, 134.91, 131.20, 128.93, 120.59, 114.54, 112.63, 110.89, 108.99, 69.21, 57.19, 35.63, 25.04, 15.52, 10.96

[0235] p.f.: 230.1-230.4° C.

[0236] HRMS (ESI/QTOF) [0237] calculated for C.sub.23H.sub.23BrNO.sub.6 (M+H.sup.+): 488.0709, [0238] found: 488.0715.

[0239] Purity (HPLC)>98%.

EXAMPLE 18

Preparation of (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalanine (6c)

[0240] ##STR00039##

[0241] The crude was prepared according to general procedure E starting from 5e (0.320 g, 0.60 mmol) and purified by recrystallisation in methanol to give 6c (0.210 g, 67%). C.sub.26H.sub.20BrNO.sub.6.

[0242] .sup.1H NMR (400 MHz, DMSO) δ 9.29 (d, J=8.2 Hz, 2H), 8.11 (dd, J=7.6, 1.0 Hz, 2H), 7.82 (t, J=8.4 Hz, 2H), 7.68 (dd, J=7.9, 0.8 Hz, 2H), 7.50 (td, J=7.6, 0.9 Hz, 2H), 7.37-7.25 (m, 11H), 7.24-7.10 (m, 4H), 6.63 (s, 2H), 5.23 (s, 4H), 4.72-4.58 (m, 2H), 3.14 (dd, J=13.8, 10.3 Hz, 5H) A peak below the water signal.

[0243] .sup.13C NMR (101 MHz, DMSO) δ 176.37, 172.20, 159.04, 157.44, 156.96, 153.00, 137.72, 135.73, 135.20, 132.16, 129.57, 129.17, 129.02, 128.25, 127.83, 126.47, 121.06, 114.45, 112.43, 110.85, 108.91, 69.75, 54.18, 36.01

[0244] p.f.: 240.4-241.7° C.

[0245] HRMS (ESI/QTOF) [0246] calculated for C.sub.26H.sub.21BrNO.sub.6 (M+H.sup.+): 522.0552, [0247] found: 522.0558.

EXAMPLE 19

Preparation of (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-phenylalanine (6d)

[0248] ##STR00040##

[0249] The crude was prepared according to general procedure E starting from 5f (0.551 g, 1.03 mmol) and purified by recrystallisation in methanol to give 6d (0.446 g, 83%). C.sub.26H.sub.20BrNO.sub.6.

[0250] .sup.1H NMR (400 MHz, DMSO) δ 8.51 (d, J=6.8 Hz, 1H), 7.72 (t, J=8.4 Hz, 1H), 7.66-7.57 (m, 4H), 7.24-7.16 (m, 5H), 7.16-7.07 (m, 2H), 6.62 (s, 1H), 5.24 (s, 2H), 4.24 (dd, J=11.0, 5.9 Hz, 1H), 3.26 (dd, J=13.5, 4.6 Hz, 1H), 3.11 (dd, J=13.5, 6.8 Hz, 1H) (ERO1-71)

[0251] .sup.13C NMR (101 MHz, DMSO) δ 176.35, 172.19, 159.11, 157.67, 156.94, 152.89, 137.66, 136.26, 135.06, 131.20, 129.02, 128.91, 128.27, 126.50, 120.58, 114.47, 112.44, 110.62, 109.04, 69.21, 54.08, 35.94

[0252] Decomposition point: 231.5° C.

[0253] HRMS (ESI/QTOF): [0254] calculated for C.sub.26H.sub.21BrNO.sub.6 ((M+H.sup.+): 522.0552, [0255] found: 522.0559.

[0256] Purity (HPLC)>95%.

EXAMPLE 20

Preparation of (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-D-tryptophan (6e)

[0257] ##STR00041##

[0258] The crude was prepared according to general procedure E starting from 5i (0.250 g, 0.27 mmol) and purified by precipitation in ethyl acetate and cyclohexane to afford 6e (0.158 g, 66%). C.sub.28H.sub.21BrN.sub.2O.sub.6.

[0259] .sup.1H NMR (400 MHz, DMSO) δ 10.87 (d, J=1.4 Hz, 1H), 9.18 (d, J=8.1 Hz, 1H), 7.79 (t, J=8.4 Hz, 1H), 7.69-7.56 (m, 5H), 7.34 (d, J=8.1 Hz, 1H) J=8.2 Hz, 1H), 7.24 (d, J=2.2 Hz, 1H), 7.13 (d, J=8.3 Hz, 1H), 7.10-7.04 (m, 1H), 7.01-6.95 (m, 1H), 6.63 (s, 1H), 5.25 (s, 2H), 4.73-4.65 (m, 1H) Two signals below the water peak.

[0260] .sup.13C NMR (101 MHz, DMSO) δ 176.37, 172.52, 159.06, 157.66, 156.92, 152.92, 136.26, 136.08, 135.04, 131.20, 128.91, 127.09, 123.66, 120.98, 120.58, 118.39, 118.16, 114.44, 112.42, 111.43, 110.59, 109.93, 109.00, 69.18, 53.73, 26.37 Two proton signals below the water peak.

[0261] m. p.: 185.5-186.7° C.

[0262] HRMS (ESI/QTOF): [0263] calculated for C.sub.28H.sub.22BrN.sub.2O.sub.6 (M+H.sup.+): 561.0661, [0264] found: 561.0672.

[0265] Purity (HPLC)>99%.

EXAMPLES 21 TO 27

Series 2

[0266] ##STR00042##

[0267] Note: In the following protocols, “molecule number+a” refers to when the bromine is in position 2 of the aromatic ring while “molecule number+b” refers to when the bromine is in position 4 of the aromatic ring.

[0268] Note: same synthesis scheme as series 1 up to step e. Only step f allowing access to compounds 7 is different.

[0269] General Operating Procedure F

[0270] To a solution of carboxylic acid derivative 6 (1 equiv) in anhydrous DMF (20 mL/mmol) was added TBTU (1.5 equiv or 2 equiv). The solution was stirred for 30 minutes at room temperature. Thus, a solution of amino acid derivative (1.5 or 2 equiv) in DMF (10 mL/mmol) in the presence of DIEA (5 equiv) was added carefully to the previous one. The reaction was stirred for 24 h at room temperature and monitored by TLC (cyclohexane/ethyl acetate 3:2). The solution was poured into acidified water (1M HCl) and extracted with ethyl acetate. The organic phases were collected and washed with a 20% NaHCO.sub.3 solution and brine before being dried over magnesium sulphate, filtered and evaporated in vacuo.

EXAMPLE 21

Preparation of methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-valinate (7a)

[0271] ##STR00043##

[0272] The crude was prepared according to general procedure F starting from 6a (0.091 g, 0.19 mmol), L-valine methyl ester (0.064 g, 0.38 mmol) and purified by precipitation in ethyl acetate and a minimal amount of cyclohexane, followed by washing with diethyl ether to provide 7a (0.042 g, 37%). C.sub.29H.sub.33BrN.sub.2O.sub.7.

[0273] .sup.1H NMR (400 MHz, DMSO) δ 8.79 (d, J=8.4 Hz, 0.5H), 8.60-8.50 (m, 1H), 8.45 (d, J=7.2 Hz, 0.5H), 8.13 (d, J=7.5 Hz, 1H), 7.81 (t, J=8.0 Hz, 1H), 7.69 (d, J=7.8 Hz, 1H), 7.52 (t, J=7.3 Hz, 1H), 7.40 (d, J=8.1 Hz, 1H), 7.33 (t, J=7.3 Hz, 1H), 7.16 (d, J=8.4 Hz, 1H), 6.72 (d, J=5.0 Hz, 1H), 5.25 (s, 2H), 4.73-4.65 (m, 0.5H), 4.54-4.45 (m, 0.5H), 4.27-4.21 (m, 0.5H), 4.21-4.14 (m, 0.5H), 3.65 (d, J=4.7 Hz, 3H), 2.13-1.92 (m, 2H), 1.64-1.47 (m, 1H), 1.28-1.14 (m, 1H), 1.04-0.70 (m, 12H).

[0274] .sup.13C NMR (101 MHz, DMSO) δ 172.31, 171.91, 171.88, 157.84, 157.83, 157.82, 157.51, 157.49, 157.46, 157.43, 157.42, 153.69, 153.67, 153.65, 135.92, 132.79, 130.34, 129.78, 128.33, 121.94, 114.74, 114.72, 114.70, 114.66, 112.89, 112.87, 112.69, 111.52, 111.46, 109.48, 109.46, 109.37, 109.35, 70.33, 70.31, 58.31, 58.30, 58.21, 58.05, 58.02, 57.96, 52.33, 52.26, 52.23, 52.21, 36.32, 30.00, 25.02, 19.31, 19.17, 19.13, 18.66, 18.59, 15.29, 15.28, 10.85.

[0275] HRMS (ESI/QTOF) [0276] calculated for C.sub.29H.sub.34BrN.sub.2O.sub.7 (M+H.sup.+): 601.1549, [0277] found: 601.1533.

EXAMPLE 22

Preparation of methyl (5-((2-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-leucinate (7b)

[0278] ##STR00044##

[0279] The crude was prepared according to general procedure F starting from 6a (0.082 mg, 0.16 mmol), L-leucine methyl ester (0.061 g, 0.32 mmol) and purified by precipitation in ethyl acetate and a minimal amount of cyclohexane, followed by washing with diethyl ether to afford 7b (0.030 g, 31%). C.sub.30H.sub.35BrN.sub.2O.sub.7.

[0280] .sup.1H NMR (400 MHz, DMSO) δ 8.79 (d, J=8.8 Hz, 0.5H), 8.64 (d, J=7.6 Hz, 1H), 8.56 (d, J=7.7 Hz, 0.5H), 8.13 (d, J=7.6 Hz, 1H), 7.81 (t, J=8.2 Hz, 1H), 7.69 (d, J=8.0 Hz, 1H), 7.52 (t, J=7.5 Hz, 1H), 7.40 (dd, J=8.3, 4.4 Hz, 1H), 7.33 (t, J=7.5 Hz, 1H), 7.16 (d, J=8.1 Hz, 1H), 6.73 (d, J=7.3 Hz, 1H), 5.25 (s, 2H), 4.64-4.56 (m, 0.5H), 4.41 (t, J=8.7 Hz, 1H), 4.37-4.27 (m, 0.5H), 3.63 (s, 1H), 2.05-1.92 (m, 1H), 1.74-1.43 (m, 4H), 1.27-1.13 (m, 1H), 0.98-0.81 (m, 12H)).

[0281] .sup.13C NMR (126 MHz, DMSO) δ 177.64, 174.72, 173.46, 173.29, 171.55, 171.48, 159.81, 159.64, 157.82, 157.41, 153.65, 153.63, 135.89, 135.84, 132.77, 130.31, 129.75, 128.32, 121.89, 114.67, 112.93, 112.88, 111.50, 109.43, 70.31, 58.05, 57.49, 52.53, 52.42, 52.32, 51.52, 51.02, 50.90, 41.57, 40.89, 37.32, 36.39, 25.92, 24.96, 24.70, 24.64, 23.10, 23.01, 22.99, 21.82, 21.57, 21.44, 21.23, 15.31, 14.95, 11.64, 10.85.

[0282] HRMS (ESI/QTOF): [0283] calculated for C.sub.30H.sub.36BrN.sub.2O.sub.7 (M+H.sup.+): 615.1690, [0284] found: 615.1684.

EXAMPLE 23

Preparation of methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-valinate (7c)

[0285] ##STR00045##

[0286] The crude was prepared according to general procedure F starting from 6a (0.123 g, 0.25 mmol), L-valine methyl ester (0.084 g, 0.50 mmol) and purified by trituration in diethyl ether to afford 7c (0.061 g, 41%). C.sub.29H.sub.33BrN.sub.2O.sub.7.

[0287] .sup.1H NMR (400 MHz, DMSO) δ 8.76 (d, J=8.6 Hz, 0.5H), 8.54 (d, J=9.4 Hz, 1H), 8.43 (d, J=7.5 Hz, 0.5H), 7.76 (t, J=8.3 Hz, 1H), 7.60 (q, J=8.6 Hz, 4H), 7.35 (d, J=8.2 Hz, 1H), 7.11 (d, J=8.3 Hz, 1H), 6.69 (d, J=5.4 Hz, 1H) 2H), 4.67 (dd, J=8.8, 6.9 Hz, 0.5H), 4.48 (t, J=8.8 Hz, 0.5H), 4.22 (dd, J=7.9, 6.9 Hz, 0.5H), 4.15 (t, J=7.0 Hz, 0.5H), 3.63 (d, J=4.9 Hz, 3H), 2.12-1.90 (m, 2H), 1.59-1.36 (m, 1H), 1.25-1.11 (m, 1H), 0.99-0.81 (m, 12H).

[0288] .sup.13C NMR (101 MHz, DMSO) δ 176.43, 171.93, 171.64, 170.88, 170.67, 159.10, 158.94, 157.64, 157.01, 153.21, 136.29, 134.90, 131.19, 128.91, 120.58, 114.52, 112.61, 112.54, 110.83, 109.00, 69.21, 57.66, 57.42, 57.24, 56.72, 51.72, 51.53, 37.09, 35.99, 29.85, 29.58, 25.65, 24.62, 19.02, 18.84, 18.35, 18.20, 14.95, 14.58, 11.37, 10.55.

[0289] HRMS (ESI/QTOF): [0290] calculated for C.sub.29H.sub.34BrN.sub.2O.sub.7 (M+H.sup.+): 601.1549, [0291] found: 601.1545.

EXAMPLE 24

Preparation of methyl (5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carbonylamino)-L-alloisoleucyl-L-leucinate (7d)

[0292] ##STR00046##

[0293] The crude was prepared according to general procedure F starting from 6b (0.123 g, 0.25 mmol), L-leucine methyl ester (0.091 mg, 0.50 mmol) and purified by trituration in diethyl ether to afford 7d (0.052 g, 34%). C.sub.30H.sub.35BrN.sub.2O.sub.7.

[0294] .sup.1H NMR (400 MHz, DMSO) δ 8.76 (d, J=8.7 Hz, 0.5H), 8.62 (d, J=7.8 Hz, 0.5H), 8.54 (dd, J=8.0, 4.5 Hz, 1H), 7.76 (t, J=8.2 Hz, 1H), 7.66-7.56 (m, 4H), 7.35 (dd, J=8.4, 4.2 Hz, 1H), 7.11 (d, J=8.2 Hz, 1H), 6.70 (d, J=7.5 Hz, 1H), 5.25 (s, 2H), 4.58 (dd, J=8.6, 6.5 Hz, 0.5H), 4.39 (t, J=8.6 Hz, 0.5H), 4.36-4.24 (m, 1H), 3.62 (d, J=2.3 Hz, 3H), 2.03-1.89 (m, 1H), 1.70-1.55 (m, 2H), 1.55-1.45 (m, 2H), 1.24-1.10 (m, 1H), 0.96-0.79 (m, 12H).

[0295] .sup.13C NMR 176.43, 172.81, 172.60, 170.56, 170.42, 159.14, 158.95, 157.63, 157.01, 153.19, 136.28, 134.90, 131.19, 128.91, 120.57, 114.51, 112.62, 112.54, 110.84, 109.00, 69.20, 57.29, 56.64, 51.86, 51.71, 50.39, 50.23, 36.98, 36.00, 25.59, 24.56, 24.23, 24.18, 22.78, 22.66, 21.28, 20.90, 14.99, 14.62, 10.54.

[0296] HRMS (ESI/QTOF): [0297] calculated for C.sub.30H.sub.36BrN.sub.2O.sub.7 (M+H.sup.+): 615.1690, [0298] found: 615.1690.

EXAMPLE 25

Preparation of (S)-5-((2-bromobenzyl)oxy)-N-(1-((2-(5-hydroxy-1H-indol-3-yl)ethyl)amino)-1-oxo-3-phenylpropan-2-yl)-4-oxo-4H-chromene-2-carboxamide (7th)

[0299] ##STR00047##

[0300] The crude was prepared according to general procedure F starting from 6c (0.127 mg, 0.24 mmol), 5-hydroxytryptamine hydrochloride (0.103 mg, 0.48 mmol) and purified by trituration in methanol, followed by washing with diethyl ether to afford 7e (0.063 g, 38%). C.sub.36H.sub.30BrN.sub.3O.sub.6.

[0301] .sup.1H NMR (400 MHz, DMSO) δ 10.49 (d, J=1.6 Hz, 1H), 9.11 (d, J=8.4 Hz, 1H), 8.61 (s, 1H), 8.31 (t, J=5.5 Hz, 1H), 8.10 (dd, J=7.7, 0.8 Hz, 1H), 7.79 (t, J=8.4 Hz, 1H), 7.65 (dd, J=8.0, 0.7 Hz, 1H), 7.48 (td, J=7.6, 0.7 Hz, 1H), 7.37-7.23 (m, 6H), 7.18 (t, J=7.2 Hz, 1H), 7.12 (d, J=8.6 Hz, 2H), 7.04 (d, J=2.1 Hz, 1H), 6.86 (d, J=2.1 Hz, 1H), 6.63 (s, 1H), 6.60 (dd, J=8.6, 2.2 Hz, 1H), 5.21 (s, 2H), 4.73-4.65 (m, 1H), 3.34-3.26 (m, 1H), 3.17 (dd, J=13.7, 4.5 Hz, 1H), 3.05 (dd, J=13.6, 10.2 Hz, 1H), 2.73 (t, J=7.5 Hz, 2H).

[0302] .sup.13C NMR (101 MHz, DMSO) δ 176.46, 170.03, 158.99, 157.41, 156.99, 153.19, 150.16, 137.88, 135.74, 135.14, 132.15, 130.81, 129.55, 129.15, 128.14, 127.83, 126.38, 123.13, 121.06, 114.44, 112.36, 111.65, 111.27, 110.93, 110.64, 108.83, 102.20, 69.74, 54.91, 37.11, 25.14. 31C+2EQ 3C MISSING.

[0303] HRMS (ESI/QTOF): [0304] calculated for C.sub.36H.sub.31BrN.sub.3O.sub.6 (M+H.sup.+): 680.1396, [0305] found: 680.1392.

EXAMPLE 26

Preparation of (S)—N-(1-((2-(1H-indol-3-yl)ethyl)amino)-1-oxo-3-phenylpropan-2-yl)-5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxamide (7f)

[0306] ##STR00048##

[0307] The crude was prepared according to general procedure F starting from 6d (0.090 g, 0.17 mmol), tryptamine hydrochloride (0.067 g, 0.34 mmol) and purified by trituration in ethyl acetate and a minimal amount of cyclohexane, followed by washing with diethyl ether to afford 7f (0.014 g, 12%). C.sub.36H.sub.30BrN.sub.3O.sub.5.

[0308] .sup.1H NMR (400 MHz, CDCl.sub.3) δ 8.20 (s, 1H), 7.68 (d, J=7.7 Hz, 1H), 7.57 (t, J=8.4 Hz, 1H), 7.54-7.44 (m, 5H), 7.32-7.15 (m, 6H), 7.12-7.06 (m, 2H), 7.06-7.01 (m, 1H), 6.89 (s, 1H), 6.85 (d, J=8.2 Hz, 1H), 6.80 (s, 1H), 5.99-5.91 (m, 1H), 5.19 (s, 2H), 4.72 (dd, J=13.5, 7.7 Hz, 1H), 3.53 (dd, J=11.8, 5.9 Hz, 2H), 3.20 (dd, J=13.4, 5.6 Hz, 1H), 3.06 (dd, J=13.3, 8.4 Hz, 1H), 2.88 (dt, J=13.1, 6.4 Hz, 1H), 2.84-2.73 (m, 1H).

[0309] .sup.13C NMR (101 MHz, CDCl.sub.3) δ 177.67, 170.09, 159.03, 158.55, 157.39, 152.34, 136.50, 136.16, 135.38, 134.72, 131.87, 129.44, 128.91, 128.45, 127.44, 127.17, 122.32, 122.19, 121.84, 119.59, 118.58, 115.56, 113.88, 112.34, 111.42, 110.84, 109.06, 70.35, 60.54, 55.24, 39.94, 38.96, 29.82, 25.00, 21.18, 14.33. 36 C INSTEAD OF 32.

[0310] HRMS (ESI/QTOF): [0311] calculated for C.sub.36H.sub.31BrN.sub.3O.sub.5 (M+H.sup.+): 664.1447, [0312] found: 664.1432.

EXAMPLE 27

Preparation of (R)—N-(1-((2-(1H-indol-3-yl)ethyl)amino)-3-(1H-indol-3-yl)-1-oxopropan-2-yl)-5-((4-bromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxamide (7 g)

[0313] ##STR00049##

[0314] The crude was prepared according to general procedure F starting from 6e (0.069 g, 0.13 mmol), tryptamine hydrochloride (0.048 g, 0.25 mmol) and purified by trituration in diethyl ether to give 7 g (0.051 mg, 59%). C.sub.38H.sub.31BrN.sub.4O.sub.5.

[0315] .sup.1H NMR (400 MHz, DMSO) δ 10.83 (s, 2H), 8.98 (d, J=8.2 Hz, 1H), 8.34 (t, J=5.3 Hz, 1H), 7.78 (t, J=8.4 Hz, 1H), 7.70 (d, J=7.7 Hz, 1H), 7.60 (q, J=8.6 Hz, 1H), 7.55 (d, J=7.8 Hz, 1H), 7.36-7.26 (m, 3H), 7.18 (dd, J=31.1, 0.9 Hz, 2H), 7.11 (d, J=8.4 Hz, 1H), 7.08-7.01 (m, 2H), 7.00-6.92 (m, 2H), 6.61 (s, 1H), 5.24 (s, 2H), 4.72-4.63 (m, 1H), 3.30-3.14 (m, 2H), 2.82 (t, J=7.3 Hz, 2H). Two signals below the water peak.

[0316] .sup.13C NMR (101 MHz, DMSO) δ 176.46, 170.44, 158.90, 157.64, 156.94, 153.16, 136.27, 136.19, 136.04, 134.99, 131.20, 128.90, 127.24, 127.15, 123.76, 122.67, 120.89, 120.88, 120.58, 118.53, 118.21, 114.43, 112.31, 111.66, 111.33, 110.67, 110.08, 108.95, 69.17, 54.44, 27.38, 25.02. 32C+2 EQ 4C MISSING.

[0317] HRMS (ESI/QTOF) [0318] calculated for C.sub.38H.sub.31BrN.sub.4O.sub.5 (M+H.sup.+): 703.1556, [0319] found: 703.1553.

EXAMPLES 28 TO 36

[0320] Series 3

##STR00050##

[0321] Note: In the following protocols, “molecule number+a” refers to when the bromines are in the 2 and 4 position of the aromatic ring while “molecule number+b” refers to when the bromines are in the 3 and 5 position of the aromatic ring.

[0322] General Operating Mode A

[0323] 2,5-dihydroxyacetophenone 3 (1 equiv) was solubilised in acetone (11 mL/mmol). Then K.sub.2CO.sub.3 (3 equiv) and tetra-n-butylammonium bromide (TBAB) (1.5 equiv) were mixed together, weighed and added to the solution. The resulting suspension was refluxed for 30 min and a solution of dibromo-1-(bromomethyl)benzene (1 equiv) in acetone (4 mL/mmol) was added. The suspension was refluxed for 30 min and then concentrated under vacuum. The reaction was monitored by TLC (cyclohexane/ethyl acetate 7:3).

[0324] The reaction mixture was poured into ethyl acetate and acidified water (1M HCl). The aqueous layer was extracted (3 times) with ethyl acetate, then the combined organic layers were washed (1 time) with acidified water (1M HCl) and brine. The combined organic layers were dried over MgSO.sub.4, filtered and evaporated under vacuum. Finally, the crude was dried under high vacuum.

[0325] General Procedure B

[0326] Sodium (6 equiv) was solubilised in cold anhydrous ethanol (3 mL/mmol) to give a fresh solution of sodium ethanoate. This solution was poured dropwise into a cold (0° C.) solution of 4 (1 equiv) in dry THF (same volume as ethanol). Then diethyl oxalate (4 equiv) was added to the solution and stirred at room temperature for 30 min. The resulting solution was warmed to 50° C. and monitored by TLC (cyclohexane/ethyl acetate 3:2). Precipitation of the reaction intermediate occurred during the reaction.

[0327] After 4 hours, drops of 37% HCl were added to the solution until the precipitate became white. The reaction was refluxed for 1.5 hours after the colour change. Then the reaction mixture was evaporated and poured into ethyl acetate and acidified water (1M HCl). The aqueous layer was extracted (3 times) with ethyl acetate until the colour changed. The combined organic layers were washed (once) with acidified water (1M HCl) and brine and dried over MgSO.sub.4 before being evaporated.

[0328] General Operating Procedure C

[0329] A solution of K.sub.2 CO.sub.3 (1.3 equiv) in water (15 mL/mmol) was added to a solution of 5 (1 equiv) in THF (30 mL/mmol) and ethanol (EtOH) (10 mL/mmol). The resulting solution was heated to 50° C. and stirred for 1.5 hours. The reaction was monitored by TLC (cyclohexane/ethyl acetate 7:3). The reaction mixture was concentrated and poured into dichloromethane and acidified water (1M HCl).

[0330] To increase the solubility of the desired product in the organic layer, a few drops of methanol were added. The aqueous layer was extracted (3 times) with dichloromethane and the combined organic layers were washed (once) with acidified water (1M HCl) and brine. Then the combined organic layers were dried over MgSO.sub.4, filtered and evaporated.

EXAMPLE 28

Preparation of 2,4-dibromo-1-(bromomethyl)benzene (2)

[0331] ##STR00051##

[0332] 2,4-dibromotoluene 1 (1000 g, 4.00 mmol) and freshly purified N-bromosuccinimide (NBS) (0.925 g, 5.20 mmol) were solubilised in 12 mL of 1,2-dichloroethane under an inert atmosphere. The solution was refluxed for 10 min and azobisisobutyronitrile (AIBN) (0.328 g, 2.00 mmol) was added. The resulting suspension was stirred and refluxed for 6 hours. The reaction was monitored by TLC (100% cyclohexane). Then the reaction mixture was evaporated and a cold 1:1 cyclohexane/dichloromethane solution was added to precipitate side products (white solid). After filtration and evaporation, crude product 2 (1.476 g, 4.49 mmol) was used directly without purification. C.sub.7H.sub.5Br.sub.3

EXAMPLE 29

Preparation of 1-(2-((2, 4-dibromobenzyl)oxy)-6-hydroxyphenyl)ethan-1-one (4a)

[0333] ##STR00052##

[0334] The crude was prepared according to general procedure A starting from 2 (1.315 g, 4.00 mmol) and 3 (1.000 g, 4.00 mmol). The crude was precipitated with a 1:1 cyclohexane/dichloromethane solution and then recrystallised in isopropanol to afford 4a (0.793 g, 50%). C.sub.15H.sub.12Br.sub.2O.sub.3.

[0335] .sup.1H NMR (400 MHz, DMSO) δ 11.64 (s, 1H), 7.95 (d, J=1.8 Hz, 1H), 7.66 (dd, J=8.2, 1.8 Hz, 1H), 7.54 (d, J=8.2 Hz, 1H), 7.32 (t, J=8.3 Hz, 1H), 6.62 (d, J=8.3 Hz, 1H), 6.55 (d, J=8.2 Hz, 1H), 5.13 (s, 2H), 2.45 (s, 3H).

[0336] .sup.13C NMR (101 MHz, DMSO) δ 203.27, 159.54, 157.71, 134.92, 134.60, 133.83, 132.06, 131.01, 123.92, 122.19, 114.68, 109.93, 103.16, 69.38, 32.88

[0337] HRMS (ESI/LTQ Orbitrap): [0338] calculated for C.sub.15H.sub.11O.sub.3Br.sub.2 (M−H.sup.+): 396.9080, [0339] found: 396.9082.

EXAMPLE 30

Preparation of 1-(2-((3,5-dibromobenzyl)oxy)-6-hydroxyphenyl)ethan-1-one (4b)

[0340] ##STR00053##

[0341] The crude was prepared according to general procedure A starting from 1,3-dibromo-5-(bromomethyl)benzene (1.315 g, 4.00 mmol) and 3 (1.000 g, 4.00 mmol). It was purified by trituration in diethyl ether to afford 4b (1.103 g, 70%). C.sub.15H.sub.12O.sub.3Br.sub.2.

[0342] .sup.1H NMR (400 MHz, DMSO) δ 11.53 (s, 1H), 7.79 (s, 1H), 7.69 (d, J=1.5 Hz, 2H), 7.29 (t, J=8.3 Hz, 1H), 6.58 (d, J=8.3 Hz, 1H), 6.54 (d, J=8.2 Hz, 1H), 5.17 (s, 2H), 2.53-2.46 (m, 5H) 13C NMR (101 MHz, DMSO) δ 203.16, 158.98, 157.30, 141.43, 133.41, 132.81, 129.45, 122.49, 115.30, 109.78, 103.40, 68.24, 32.91

[0343] HRMS (ESI/LTQ Orbitrap): [0344] calculated for C.sub.15H.sub.11O.sub.3Br.sub.2 (M−H.sup.m) 396.9080, [0345] found: 396.9078.

EXAMPLE 31

Preparation of ethyl 5-((2,4-dibromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxylate (5a)

[0346] ##STR00054##

[0347] The crude was prepared according to general procedure B starting from 4a (0.435 g, 1.09 mmol) and diethyl oxalate (0.636 g, 4.35 mmol). The resulting oil was solidified under high vacuum and isopropanol was added and heated.

[0348] The resulting suspension was filtered, and the paste-like product was dissolved in dichloromethane to obtain a white solid after evaporation. The desired product 5a (0.144 g, 27%). C.sub.19H.sub.14O.sub.5Br.sub.2.

[0349] .sup.1H NMR (400 MHz, DMSO) δ 8.08 (d, J=8.3 Hz, 1H), 7.94 (d, J=1.9 Hz, 1H), 7.80 (t, J=8.4 Hz, 1H), 7.74 (dd, J=8.3, 1.9 Hz, 1H), 7.29 (d, J=8.5 Hz, 1H), 7.15 (d, J=8.3 Hz, 1H), 6.81 (s, 1H), 5.19 (s, 2H), 4.40 (q, J=7.1 Hz, 2H), 1.36 (t, J=7.1 Hz, 3H)

[0350] .sup.13C NMR (101 MHz, DMSO) δ 176.44, 159.99, 157.23, 157.22, 150.30, 135.46, 135.43, 134.04, 130.85, 130.60, 121.82, 121.29, 115.42, 114.59, 110.90, 108.90, 69.29, 62.62, 13.87

[0351] HRMS (ESI/LTQ Orbitrap): [0352] calculated for C.sub.19H.sub.15O.sub.5Br.sub.2 (M+H.sup.+): 480.9281, [0353] found: 480.9271.

EXAMPLE 32

Preparation of ethyl 5-((3,5-dibromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxylate (5b)

[0354] ##STR00055##

[0355] The crude was prepared according to general procedure B starting from 4b (1.103 g, 2.76 mmol) and diethyl oxalate (1.612 g, 14.03 mmol). It was purified by trituration in diethyl ether to afford 5b (0.785 g, 59%). C.sub.19H.sub.14Br.sub.2O.sub.5.

[0356] .sup.1H NMR (400 MHz, DMSO) δ 7.91 (d, J=1.6 Hz, 2H), 7.81-7.74 (m, 2H), 7.26 (d, J=8.1 Hz, 1H), 7.08 (d, J=8.3 Hz, 1H), 6.83 (s, 1H), 5.27 (s, 2H), 4.38 (q, J=7.1 Hz, 2H), 1.34 (t, J=7.1 Hz, 3H).

[0357] .sup.13C NMR (101 MHz, DMSO) δ 176.55, 159.99, 157.32, 157.22, 150.28, 141.68, 135.40, 132.26, 128.38, 122.44, 115.46, 114.62, 110.82, 108.83, 68.21, 62.60, 13.86

[0358] HRMS (ESI/LTQ Orbitrap): [0359] calculated for C.sub.19H.sub.15Br.sub.2O (M+H.sup.+): 480.9281, [0360] found: 480.9274.

EXAMPLE 33

Preparation of 5-((2,4-dibromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxylic acid (6a)

[0361] ##STR00056##

[0362] The crude was prepared according to general procedure C starting from 5a (0.144 g, 0.30 mmol) and purified by trituration in 1:1 diethyl ether/dichloromethane to afford 6a (0.074 g, 55%). C.sub.17H.sub.10Br.sub.2O.sub.5.

[0363] .sup.1H NMR (400 MHz, DMSO) δ 8.07 (d, J=8.3 Hz, 1H), 7.90 (d, J=1.9 Hz, 1H), 7.76 (t, J=8.4 Hz, 1H), 7.70 (dd, J=8.3, 1.9 Hz, 1H), 7.24 (d, J=8.3 Hz, 1H), 7.10 (d, J=8.3 Hz, 1H), 6.75 (s, 1H), 5.15 (s, 2H).

[0364] .sup.13C NMR (101 MHz, DMSO) δ 176.72, 161.42, 157.30, 157.17, 151.21, 135.46, 135.28, 133.97, 130.81, 130.55, 121.71, 121.23, 115.20, 114.54, 110.90, 108.69, 69.23, 64.89

[0365] HRMS (ESI/LTQ Orbitrap): [0366] calculated for C.sub.17H.sub.11Br.sub.2O.sub.5 (M+H.sup.+): 454.8948, [0367] found: 454.8937.

EXAMPLE 34

Preparation of 5-((3,5-dibromobenzyl)oxy)-4-oxo-4H-chromene-2-carboxylic Acid (6b)

[0368] ##STR00057##

[0369] The crude was prepared according to general procedure C starting from 5b (0.785 g, 1.63 mmol) and purified by trituration in 1:1 diethyl ether/dichloromethane to afford 6b (0.493 g, 67%). C.sub.17H.sub.10Br.sub.2O.sub.5.

[0370] .sup.1H NMR (400 MHz, DMSO) δ 7.91 (s, 2H), 7.82-7.72 (m, 2H), 7.24 (d, J=8.4 Hz, 1H), 7.06 (d, J=8.3 Hz, 1H), 6.79 (s, 1H), 5.27 (s, 2H)

[0371] .sup.13C NMR (101 MHz, DMSO) δ 176.82, 161.44, 157.31, 157.29, 151.21, 141.70, 135.23, 132.22, 128.34, 122.42, 115.23, 114.58, 110.83, 108.67, 68.19

[0372] HRMS (ESI/LTQ Orbitrap): [0373] calculated for C.sub.17H.sub.11Br.sub.2O.sub.5 (M+H.sup.+): 454.8948, [0374] found: 454.8941.

EXAMPLE 35

Preparation of 5-((2,4-dibromobenzyl)oxy)-N-(2-(5-methoxy-1H-indol-3-yl)ethyl)-4-oxo-4H-chromene-2-carboxamide (7a)

[0375] ##STR00058##

[0376] 6a (0.074 g, 0.16 mmol) was solubilised in 2 mL of anhydrous DMF. Subsequently, DIEA (0.084 g, 0.65 mmol) and TBTU (0.105 g, 0.33 mmol) were added successively to the solution. After complete dissolution, 5-methoxytryptamine (0.074 g, 0.33 mmol) was added and the resulting solution was stirred at room temperature for 24 hours. The reaction was monitored by TLC (cyclohexane/ethyl acetate 1:4).

[0377] The reaction mixture was poured into acidified water (1M HCl) and extracted (3 times) with dichloromethane. The organic phases were collected and washed (once) with acidified water (1M HCl), basified water (10% NaOH) and brine before being dried over MgSO.sub.4, filtered and evaporated. The resulting oil was precipitated with a few drops of diethyl ether.

[0378] After filtration, the crude product was purified using a 12 g silica column and as eluent cyclohexane/dichloromethane 4:1 to 100% dichloromethane. After elution of a first product, the desired product was obtained with 9:1 dichloromethane/methanol. The desired product 7a (0.006 g, 5.6%) is a solid. C.sub.28H.sub.22Br.sub.2N.sub.2O.sub.5

[0379] .sup.1H NMR (500 MHz, CDCl.sub.3) δ 8.12 (d, J=8.4 Hz, 1H), 8.00 (s, 1H), 7.72 (d, J=1.9 Hz, 1H), 7.60-7.55 (m, 2H), 7.31 (d, J=8.8 Hz, 1H), 7.10 (dd, J=9.8, 2.3 Hz, 2H), 7.05 (s, 1H), 6.95-6.89 (m, 3H), 6.85 (dd, J=8.4, 0.5 Hz, 1H), 5.16 (s, 2H), 3.84-3.78 (m, 5H), 3.11 (t, J=6.6 Hz, 2H)

[0380] .sup.13C NMR (126 MHz, CDCl.sub.3) δ 177.59, 159.14, 158.11, 157.22, 154.32, 152.90, 134.78, 134.48, 134.36, 131.54, 131.28, 130.13, 127.80, 122.96, 121.80, 121.15, 115.29, 113.68, 112.63, 112.36, 112.17, 110.59, 108.41, 100.40, 69.86, 55.84, 40.52, 24.94

[0381] HRMS (ESI/LTQ Orbitrap) [0382] calculated for C.sub.28H.sub.23Br.sub.2N.sub.2O.sub.5 (M+H.sup.+): 626.9948, [0383] found: 626.9929.

EXAMPLE 36

Preparation of ((3,5-dibromobenzyl)oxy)-N-(2-(5-methoxy-1H-indol-3-yl)ethyl)-4-oxo-4H-chromene-2-carboxamide (7b)

[0384] ##STR00059##

[0385] 6b (0.100 g, 0.22 mmol) was solubilised in anhydrous DMF (10 mL) and stirred until completely dissolved. Then (1H-benzotriazol-1-yloxy) (tri-1-pyrrolidinyl)phosphonium hexafluorophosphate (PyBOP) coupling agent (0.195 g, 0.44 mmol) was added to the solution followed by DIEA (0.114 g, 0.88 mmol). The solution was stirred at room temperature for 1 hour. A colour change appeared.

[0386] Then 5-methoxytryptamine (0.100 g, 0.44 mmol) was added and the solution was stirred at room temperature for 2 days. With no change in cyclohexane/ethyl acetate 1:1 TLC, bis(2-oxo-1,3-oxazolidin-3-yl)phosphinic chloride (BOP—Cl) (0.112 g, 0.44 mmol) was added to the solution. After 2 days, a 1:1 cyclohexane/ethyl acetate TLC showed the formation of products.

[0387] The reaction mixture was evaporated and poured into ethyl acetate. The organic phase was washed (3 times) with basified water (saturated K.sub.2CO.sub.3), then acidified water (1M HCl) and brine. The organic layer was dried over MgSO.sub.4 and evaporated to obtain a brown solid.

[0388] The solid was purified by silica column chromatography using a dry sample and an eluent such as 100% dichloromethane followed by 2.4:0.1 dichloromethane/methanol. The 5 mL fractions were kept overnight in a fume hood to precipitate the desired product. After filtration, the desired product 7b, (0.007 g, 6.6%) was obtained. C.sub.28H.sub.22O.sub.5N.sub.2Br.sub.2

[0389] .sup.1H NMR (400 MHz, DMSO) δ 10.71 (s, 1H), 9.23 (t, J=5.8 Hz, 1H), 7.94 (d, J=1.3 Hz, 2H), 7.85-7.79 (m, 2H), 7.30 (d, J=8.4 Hz, 1H), 7.24 (d, J=8.7 Hz, 1H), 7.19 (d, J=2.1 Hz, 1H), 7.12-7.06 (m, 2H), 6.76-6.70 (m, 2H), 5.30 (s, 2H), 3.75 (s, 3H), 3.58 (dd, J=14.2, 6.6 Hz, 2H), 2.97 (t, J=7.4 Hz, 2H)

[0390] .sup.13C NMR (126 MHz, DMSO) δ 177.14, 159.37, 157.83, 157.49, 154.21, 153.51, 142.26, 135.54, 132.78, 131.88, 128.94, 128.03, 123.91, 122.94, 114.95, 112.57, 112.53, 111.72, 111.56, 111.36, 109.32, 100.65, 68.76, 55.81, 25.35

[0391] HRMS (ESI/LTQ Orbitrap): [0392] calculated for C.sub.28H.sub.23O.sub.5N.sub.2Br.sub.2 (M+H.sup.+): 626.9948, [0393] found: 626.9937.

EXAMPLE 37

Biological Evaluation

Materials

[0394] High glucose DMEM (Dulbecco/Vogt modified Eagle's minimal medium) with GlutaMAX™ (Gibco) and fetal calf serum (FBS, GE Healthcare Hyclone) were purchased from Fisher Scientific. Penicillin/streptomycin (10,000 U/10 mg per ml), G418, trypsin and Dulbecco's phosphate buffered saline (DPBS) were purchased from Sigma Aldrich (France), as well as mitoxantrone (MX), rhodamine 123 (R123), calcein-AM (cAM) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). All commercial products were of the highest purity available.

Compounds

[0395] All chromone derivatives were dissolved in dimethyl sulphoxide (DMSO) and then diluted in high glucose DMEM. Stock solutions were stored at −20° C. and warmed to 25° C. just prior to use.

Cell Lines and Cultures

[0396] ABCB1-transfected NIH/3T3, ABCC1-transfected Flp-In 293 and ABCG2-transfected HEK293 cells and their empty plasmid counterparts were generated as previously described (Borst, P.; Elferink, R. O. Mammalian ABC Transporters in Health and Disease. Annu. Rev. Biochem. 2002, 71 (1), 537-592).

[0397] Specifically, the ABCG2-transfected HEK293 monoclonal cell line was selected after fluorescence-activated cell sorting (FACS) using a phycoerythrin-coupled 5D3 antibody (Santa Cruz Biotech) as an endogenous expression reporter.

[0398] Cells were grown and maintained in high glucose DMEM with GlutaMAX™ supplemented with 10% heat-inactivated fetal calf serum (FBS) and 1% penicillin/streptomycin in a humidified atmosphere at 37° C. with 5% CO.sub.2. In addition, 200 μg/mL hygromycin B, 90 ng/mL colchicine or 750 μg/mL G418 were added to the growth medium as selection agents for NIH/3T3, Flp-In 293 or HEK293 transfected cells, respectively.

Cytotoxicity Tests

[0399] The cytotoxicity of compounds was determined using a colorimetric MTT assay as reported in the literature (Linton, K. J. Structure and Function of ABC Transporters. Physiology 2007, 22 (2), 122-130. Sharom, F. J. ABC Multidrug Transporters: Structure, Function and Role in Chemoresistance. Pharmacogenomics 2008, 9 (1), 105-127).

[0400] Briefly, cells were seeded in 96-well plates at a density of 1×10.sup.5 cells/well for a total growth medium volume of 100 μL and incubated overnight. Then, 100 μL of fresh medium containing increasing concentrations of compounds (dissolved in DMSO in a concentration range of 0, 2 and 20 μM) to be tested were added to each well while the DMSO control was fixed at 0.5% (v/v). After incubation for 72 hours, 22 μL of MTT dye in PBS (5 mg/mL) was added to each well and the plates were incubated for a further 4 hours at 37° C. After removal of the medium and drying, the formazan dye crystals were solubilised with 200 μL of DMSO/ethanol (1:1, v/v). The absorbance was measured using spectrophotometry at 570 nm and 690 nm as reference wavelength. The effect of each compound on cell viability in all cell lines was calculated as the difference in absorbance between the test and control media wells.

[0401] The cytotoxicity results of the compounds according to the invention are shown in Table 1.

TABLE-US-00001 Cell viability(%) Compound [Compound] 1 pM [Compound] 10 pM 5a (series 1) / / 5b (series 1) 78 ± 0 87 ± 1 5c (series 1) 82 ± 2 76 ± 1 5d (series 1) 75 ± 1 82 ± 6 5th (series 81 ± 3 88 ± 1 1) 5f (series 1) 82 ± 6 84 ± 3 5g (series 1) 73 ± 4 77 ± 0 5h (series 1) 83 ± 2 102 ± 1 5i (series 1) 78 ± 0 87 ± 1 7a (series 2) 104 ± 16 102 ± 12 7b (series 2) 100 ± 18 104 ± 11 7c (series 2) 106 ± 30 89 ± 22 7d (series 2) 118 ± 12 101 ± 12 DMSO 0.5 % 100 100

[0402] The compounds according to the invention therefore exhibit very low cytotoxicity or no cytotoxicity.

[0403] MDR-Related Drug Efflux Inhibition Tests

[0404] The cells were seeded in 96-well plates at a density of 5×10.sup.4 cells/well in 200 μL of medium and incubated overnight. Then the growth medium was changed to fresh medium containing the compounds and in the presence of 4 μM MX as a fluorescent probe for BCRP-mediated efflux at a final concentration of 0.5% (v/v) DMSO. After 30 min incubation at 37° C., the medium was removed, and the cells were washed with 100 μL of Dulbecco's phosphate-buffered saline (DPBS) followed by dissociation of the cells for 5 min at 37° C. mediated by 25 μL trypsin. Finally, trypsin was neutralised with 175 μL of DPBS ice-cold with 2% bovine serum albumin (BSA) and the cells were carefully resuspended. As a selectivity assay, the same experiment was performed for P-gp and MRP1-mediated efflux with 0.5 μM R123 or 0.2 μM cAM as respective fluorescent substrates instead of MX.

[0405] Intracellular fluorescence was measured with a MacsQUANT VRB Analyzer flow cytometer (Miltenyi Biotec) with at least 5000 events recorded. While MX was excited at 635 nm and the fluorescence emission recorded in a 655-730 nm window, R123 and cAM were excited at 488 nm and recorded in a 525/50 nm filter. The compound inhibition yield was estimated by the following equation:

[00001]$\begin{array}{cc}\%\mathrm{of}\mathrm{inhibition}=100*\frac{\left[\left(G{2}_{\mathrm{FA}}-G{2}_{FBG}\right)-\left(G{2}_S-G{2}_{FBG}\right)\right]}{\left[\left(HE{K}_{FA}-HE{K}_{FBG}\right)-\left(G{2}_S-G{2}_{FBG}\right)\right]}& \left[\mathrm{Math}.1\right]\end{array}$

where G2.sub.FA is the fluorescence emission (a.u.) of accumulated fluorophore in cells expressing the efflux pump incubated with a fluorescent substrate and the test compound. G2.sub.FBG is the resulting background fluorescence emission (a.u.) in cells transfected with ABCG2 (no substrate or test compound). G2.sub.S is the fluorescence emission (a.u.) of accumulated fluorophore in cells expressing the efflux pump incubated with substrate only. HEK.sub.FA is the fluorescence emission (a.u.) of accumulated fluorophore in control cells incubated with the substrate and test compound. HEK.sub.FBG is the resulting background fluorescence emission (a.u.) in control cells (no substrate or test compound). All values are given as the geometric mean fluorescence emission (a.u.) in a 655-730 nm filter (635 nm excitation) measured over 5000 events. The tests were performed in triplicate.

Activity of Chromones as ABCG2 Inhibitors

[0406]

TABLE-US-00002 TABLE 2 Absolute Inhibition (%) IC.sub.50 Input Position of R.sub.1 Br configuration 1 μM 10 μM (μM) SERIES 1 5a 2 —CH(CH.sub.3)CH.sub.2CH.sub.3 S 78 ± 9  143 ± 22  0.10 ± 0.01 5b 4 —CH(CH.sub.3)CH.sub.2CH.sub.3 S —  115 ± 14% 0.59 ± 0.08 5c 2 —CH.sub.2CH(CH.sub.3).sub.2 S 115 ± 17  101.5 ± 21.7  0.14 ± 0.04 5d 2 —CH(CH.sub.3).sub.2 S 87 ± 7  148.2 ± 6.7  0.05 ± 0.03 5e 2 —CH.sub.2Ph S 100 ± 14  84.6 ± 2.0  0.10 ± 0.07 5g 2 —CH.sub.2(3-indolyl) S 93.7 ± 17   39.7 ± 3.7  n.a. 5f 4 —CH.sub.2Ph S 92 ± 15 114 ± 11  0.27 ± 0.11 5h 4 —CH.sub.2(3-indolyl) S 92 ± 15 87.7 ± 12   0.48 ± 0.07 5i 4 —CH.sub.2(3-indolyl) R 85 ± 12 96.3 ± 19   0.29 ± 0.05 6a 2 —CH(CH.sub.3)CH.sub.2CH.sub.3 S 0.0 ± 0.7 1.6 ± 3.1 n.a. 6d 4 —CH.sub.2Ph S 4.0 ± 0.7 6.5 ± 0.0 n.a. 6e 4 —CH.sub.2(3-indolyl) R 6.1 ± 0.6 11.2 ± 2.0  n.a. SERIES 2 7a 2 —CH(CH.sub.3)CH.sub.2CH.sub.3 S 0.07 ± 0.01 7b 2 —CH(CH.sub.3)CH.sub.2CH.sub.3 S 0.07 ± 0.01 7c 4 —CH(CH.sub.3)CH.sub.2CH.sub.3 S 0.25 ± 0.10 7d 4 —CH(CH.sub.3)CH.sub.2CH.sub.3 S 0.11 ± 0.03 SERIES 3 7a 2, 4 H / / 0.05 ± 0.01 7b 3, 5 H / / 0.10 ± 0.01 MBL- 4 0.13 ± 0.09 II-141 0.09 Ko143
The above table shows that the compounds show good IC50 values. In particular, compounds 5d in series 1, 7a and 7b in series 2 and 7a in series III show better results than the MBL-II-141 inhibitor and the reference inhibitor Ko143.
Chromone Selectivity for BCRP Vs. P-Gp and MRP1

TABLE-US-00003 P-gp MRP1 BCRP entry [Inhibitor] μM Inhibition (%) 5a (series 1     / 1) 10 5c (series 1 7.0 ± 1.1 20.2 ± 2.7 114.5 1) 10 4.8 ± 0.7 19.2 ± 2.2 / 5d (series 1 7.9 ± 0.7 12.6 ± 1.3 86.6 1) 10 6.5 ± 1.9 17.8 ± 0.9 / 5th (series 1 4.9 ± 0.8 25.8 ± 0.8 100.2 1) 10 5.7 ± 1.4 29.2 ± 1.5 / 5f (series 1 6.4 ± 1.5 23.0 91.6 1) 10 6.8 ± 1.4 19.0 / 5g (series 1 7.4 ± 0.3 23.0 ± 2.5 93.7 1) 10 5.3 ± 0.5 16.0 ± 2.5 / 5h (series 1 7.4 ± 2.5 10.3 96.4 1) 10 6.6 ± 1.4 17.4 / 5i (series 1 7.2 ± 1.3 11.9 84.8 1) 10 6.1 ± 1.1 12.6 / 6a (series 1 7.8 1.8 17.1 / 1) 10  7.9 ± 2.3 13.1 ± 2.4 / 6b (series 1  7.7 ± 1.9 21.9 ± 4.6 / 1) 10  7.1 ± 0.6 20.6 ± 1.2 / 6c (series 1  7.7 ± 2.0 20.0 ± 3.7 / 1) 10  6.3 ± 1.4 18.1 ± 1.2 / 7a (series 1  0.1 ± 0.0 11.1 ± 0.8 84.8 ± 7.4 2) 10  0.2 ± 0.0 10.8 ± 2.8 / 7b (series 1  1.7 ± 2.4 10.3 ± 0.7 82.5 ± 9.7 2) 10  2.4 ± 0.5 ± 0.6 / 7c (series 1  2.4 ± 2.1 11.5 ± 0.4 72.4 ± 7.1 2) 10 10.6 ± 0.3 15.3 ± 1.5 / 7d (series 1  3.6 ± 0.2 10.9 ± 1.4 52.3 ± 5.1 2) 10  5.9 ± 0.1 14.7 ± 1.0