PHENYL AND TERTBUTYLACETIC ACID SUBSTITUTED PYRIDINONES HAVING ANTI-HIV EFFECTS

Abstract

Compounds of Formula I are disclosed and methods of treating viral infections with compositions comprising such compounds.

##STR00001##

Claims

1. A compound of Formula I: ##STR00057## wherein: R.sup.1 is phenyl optionally substituted by one to four substituents selected from C.sub.1-3alkyl, halogen, or —CH.sub.2CH.sub.2CH.sub.2O— wherein this group is bonded to adjacent carbon atoms on the phenyl to form a ring; L is a bond, C.sub.1-3alkylene, —SO.sub.2—, —SO.sub.2CH.sub.2—, —NHSO.sub.2—, —NHSO.sub.2CH.sub.2—, —C(O)—, —C(O)NH—, —C(O)NHCH.sub.2—, —C(O)OCH.sub.2—, —C(O)C(O)—, —CH.sub.2C(O)—, C.sub.3-7heteroaryl, or —C.sub.3-7heteroarylNH—, wherein each heteroaryl comprises one to three heteroatoms selected from S, N, and O; R.sup.2 is H, cyclohexyl, or phenyl wherein said cyclohexyl and phenyl are optionally substituted by one to three substituents selected from C.sub.1-3alkyl and halogen R.sup.3 is H or —NHSO.sub.2R.sup.4 wherein R.sup.4 is C.sub.1-8alkyl and wherein said alkyl can include cycloalkyl portions.

2. A compound according to claim 1 wherein R.sup.1 is phenyl optionally substituted by a methyl group.

3. A compound according to claim 1 wherein L is a bond, —oxadiazolyl-NH—, —C(O)NH—, or —C(O)NHCH2—.

4. A compound according to claim 1 wherein R.sup.2 is H, cyclohexyl, or phenyl wherein said cyclohexyl and phenyl are optionally substituted by 1 or 2 methyl groups.

5. A compound according to claim 1 wherein R.sup.3 is H, —NHSO.sub.2CH3, or —NHSO.sub.2CH.sub.2cyclohexyl.

6. A compound according to claim 1 wherein the stereochemistry on the carbon to which the t-butyl group is bound is as depicted below. ##STR00058##

7. A pharmaceutically acceptable salt of a compound according to claim 1.

8. A pharmaceutical composition comprising a compound according to claim 1 or a pharmaceutically acceptable salt thereof.

9. A method for treating a viral infection in a patient mediated at least in part by a virus in the retrovirus family of viruses, comprising administering to said patient a composition according to claim 8.

10. The method of claim 9 wherein said viral infection is mediated by the HIV virus.

11-13. (canceled)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0017] Preferably R.sup.1 is phenyl optionally substituted by a methyl group.

[0018] Preferably L is a bond, -oxadiazolyl-NH—, —C(O)NH—, or —C(O)NHCH.sub.2—.

[0019] Preferably R.sup.2 is H, cyclohexyl, or phenyl wherein said cyclohexyl and phenyl are optionally substituted by 1 or 2 methyl groups.

[0020] Preferably R.sup.3 is H, —NHSO.sub.2CH.sub.3, or —NHSO.sub.2CH.sub.2cyclohexyl.

[0021] Preferably the stereochemistry on the carbon to which the t-butyl group is bound is as depicted below.

##STR00003##

[0022] “Pharmaceutically acceptable salt” refers to pharmaceutically acceptable salts derived from a variety of organic and inorganic counter ions well known in the art and include, by way of example only, sodium, potassium, calcium, magnesium, ammonium, and tetraalkylammonium, and when the molecule contains a basic functionality, salts of organic or inorganic acids, such as hydrochloride, hydrobromide, tartrate, mesylate, acetate, maleate, and oxalate. Suitable salts include those described in P. Heinrich Stahl, Camille G. Wermuth (Eds.), Handbook of Pharmaceutical Salts Properties, Selection, and Use; 2002.

EXAMPLES

[0023] The compounds of this invention may be made by a variety of methods, including well-known standard synthetic methods. Illustrative general synthetic methods are set out below and then specific compounds of the invention are prepared in the working examples.

##STR00004## ##STR00005##

Example 1

4,4-Dimethyl-2-(5-methyl-4-(((1r,4r)-4-methylcyclohexyl)carbamoyl)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoic acid

[0024] ##STR00006##

Step 1: (E)-Ethyl 2-(4-hydroxybut-2-enamido)-4,4-dimethylpentanoate

[0025] ##STR00007##

[0026] To a solution of (E)-4-hydroxybut-2-enoic acid (418 mg, 4.09 mmol) in DMF (5 mL) were added DIPEA (3.5 mL, 20.5 mmol), HBTU (3.2 g, 8.2 mmol) and ethyl 2-amino-4,4-dimethylpentanoate (1.05 g, 6.1 mmol). After 30 min, the reaction mixture was partitioned between DCM and water. The layers were separated and the aqueous layer was extracted with DCM (20 mL×2). The combined organic layers was washed with NaHCO.sub.3 (aq.) and brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=1:1) to afford the title compound as a yellow solid (1.05 g, 64% yield). LC-MS (ESI): m/z (M+1)=258.23.

Step 2: (E)-ethyl 2-(4-(tert-butyldimethylsilyloxy)but-2-enamido)-4,4-dimethylpentanoate

[0027] ##STR00008##

[0028] To a solution of (E)-ethyl 2-(4-hydroxybut-2-enamido)-4,4-dimethylpentanoate (1.05 g, 4.1 mmol) in DCM (10 mL) were added DMAP (498 mg, 4.1 mmol), imidazole (833 mg, 12.3 mmol) and TBSCI (922 mg, 6.2 mmol). After 2 h, the reaction mixture was quenched with H.sub.2O and extracted with DCM (20 ml×3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=5:1) to afford the title compound as a yellow oil (800 mg, 53% yield). LC-MS (ESI): m/z (M+1)=372.24.

Step 3: Ethyl 2-(4-((tert-butyldimethylsilyloxy)methyl)-5-methyl-2-oxo-6-p-tolylpyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0029] ##STR00009##

[0030] 1-Methyl-4-(prop-1-yn-1-yl)benzene was prepared from the known procedure as described in Angew. Chem. Int. Edit., 2012 51, 1287-1294.

[0031] A mixture of (E)-ethyl 2-(4-(tert-butyl dimethylsilyloxy)but-2-enamido)-4,4-adimethyl pentanoate (300 mg, 0.81 mmol), 1-methyl-4-(prop-1-ynyl)benzene (132 mg, 1.0 mmol), RhCp*(MeCN).sub.3(SbF.sub.6).sub.2 (33.7 mg, 0.04 mmol) and Cu(OAc).sub.2.H.sub.2O (340 mg, 1.7 mmol) in DCE (10 mL) was stirred at 80°. After 18 h, the mixture was cooled down to ambient temperature and quenched with 10% NH.sub.3.H.sub.2O in saturated NH.sub.4Cl (aq.) and extracted with DCM (20 mL×3). The combined organic layers was washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, 2% MeOH in DCM) to afford the title compound as a yellow solid (114 mg, 28% yield). LC-MS (ESI): m/z (M+1)=500.31

Step 4: Ethyl 2-(4-(hydroxymethyl)-5-methyl-2-oxo-6-p-tolylpyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0032] ##STR00010##

[0033] To a solution of ethyl 2-(4-((tert-butyldimethylsilyloxy)methyl)-5-methyl-2-oxo-6-p-tolyl pyridin-1(2H)-yl)-4,4-dimethylpentanoate (114 mg, 0.23 mmol) in THF (3 mL) was added TBAF (120 mg, 0.46 mmol). After 1 h, the reaction mixture was partitioned between EtOAc and water. The layers were separated and the organic layer was washed with H2O and brine, dried over Na2SO4, filtered and concentrated under reduced pressure to give the title compound as a yellow oil (108 mg, quant. yield) which was used in next step without further purification. LC-MS (ESI): m/z (M+1) 386.18.

Step 5: Ethyl 2-(4-formyl-5-methyl-2-oxo-6-p-tolylpyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0034] ##STR00011##

[0035] A solution of ethyl 2-(4-(hydroxymethyl)-5-methyl-2-oxo-6-p-tolylpyridin-1(2H)-yl)-4,4-dimethylpentanoate (108 mg, 0.28 mmol) in DCM (5 mL) was added DMP (214 mg, 0.50 mmol). After 1 h, the reaction mixture was quenched with NaHCO.sub.3 (aq.) and extracted with DCM (20 ml×3). The combined organic layers was washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=2:1) to afford the title compound as a yellow solid (63 mg, 58% yield). LC-MS (ESI): m/z (M+1)=384.3.

Step 6: 1-(1-Ethoxy-4,4-dimethyl-1-oxopentan-2-yl)-5-methyl-2-oxo-6-p-tolyl-1,2-dihydropyridine-4-carboxylic acid

[0036] ##STR00012##

[0037] To a solution of ethyl 2-(4-formyl-5-methyl-2-oxo-6-p-tolylpyridin-1(2H)-yl)-4,4-dimethylpentanoate (63 mg, 0.16 mmol) in THF (2.2 mL), t-BuOH (2.2 mL) and isobutylene (4.5 ml) in a sealed tube was added a solution of NaH.sub.2PO.sub.4 and NaClO.sub.2in H.sub.2O (5 mL). After 18 h, the reaction mixture was acidified with 1N HCl (0.5 mL) and extracted with ethyl acetate (20 ml×3). The combined organic layers was washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the title compound as a yellow solid (51 mg, 80% yield) which was used in next step without further purification. LC-MS (ESI): m/z (M+1)=400.1

Step 7: Ethyl 4,4-dimethyl-2-(5-methyl-4-((1r,4r)-4-methylcyclohexylcarbamoyl)-2-oxo-6-p-tolylpyridin-1(2H)-yl)pentanoate

[0038] ##STR00013##

[0039] A solution of 1-(1-ethoxy-4,4-dimethyl-1-oxopentan-2-yl)-5-methyl-2-oxo-6-p-tolyl-1,2-dihydropyridine-4-carboxylic acid (28 mg, 0.07 mmol) in DMF (2 mL) was treated with DIPEA (0.06 ml, 0.35 mmol), HBTU (54.2 mg, 0.14 mmol) and trans-4-methyl cyclohexyl amine (0.02 ml, 0.14 mmol). After 18 h, the reaction mixture was diluted with water and extracted with DCM (20 ml×3). The combined organic layers was washed with NaHCO.sub.3 (aq.) and brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by prep. TLC (PE:EA=1:1) to afford the title compound as a yellow solid (30 mg, 86%). LC-MS (ESI): m/z (M+1)=495.37.

Step 8: 4,4-Dimethyl-2-(5-methyl-4-((1r,4r)-4-methylcyclohexylcarbamoyl)-2-oxo-6-p-tolylpyridin-1(2H)-yl)pentanoic acid

[0040] ##STR00014##

[0041] To a solution of ethyl 4,4-dimethyl-2-(5-methyl-4-((1r,4r)-4-methylcyclohexylcarbamoyl)-2-oxo-6-p-tolylpyridin-1(2H)-yl)pentanoate (30 mg, 0.06 mmol) in MeOH (2 mL) was added 1 N NaOH (0.6 mL) and heated to reflux. After 18 h, the reaction mixture was cooled to ambient temperature, acidified with 1 N HCl (0.6 mL) (pH=6˜7) and concentrated under reduced pressure to give the crude product which was purified by reverse phase HPLC (C.sub.18 70˜100% CH.sub.3CN in H.sub.2O with 0.1% formic acid) to afford the title compound as a white powder (12 mg, 40% yield). .sup.1H NMR (400 MHz, DMSO) δ 8.43 (d, J=8.0 Hz, 1H), 7.46-7.31 (m, 3H), 7.28 (d, J=8.1 Hz, 1H), 6.24 (s, 1H), 4.19 (s, 1H), 3.63-3.58 (m, 1H), 2.39 (s, 3H), 2.31-2.23 (m, 1H), 1.92-1.77 (m, 3H), 1.76-1.60 (m, 5H), 1.32-1.23 (m, 3H), 1.05-0.95 (m, 2H), 0.87 (d, J=6.5 Hz, 3H), 0.58 (s, 9H). LC-MS (ESI): m/z (M+1)=467.33.

##STR00015##

Example 2

2-(4-(3,4-Dimethylphenyl)-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoic acid

[0042] ##STR00016##

Step 1: (E)-Ethyl 2-(3-(3,4-dimethylphenyl)acrylamido)-4,4-dimethylpentanoate

[0043] ##STR00017##

[0044] A mixture of (E)-3-(3,4-dimethylphenyl)acrylic acid (200 mg, 1.14 mmol), ethyl 2-amino-4,4-dimethylpentanoate (240 mg, 1.4 mmol), HBTU (880 mg, 2.3 mmol) and DIPEA (733 mg, 5.7 mmol) in DCM (10 mL) was stirred at r.t. for 40 min. The reaction mixture was diluted with sat. NaHCO.sub.3 (aq.) and extracted with DCM (20 ml×3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=3:1) to afford the title compound as a yellow oil (288 mg, 77% yield). LC-MS (ESI): m/z (M+1)=332.3.

Step 2: Ethyl 2(-4-(3,4-dimethylphenyl)-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0045] ##STR00018##

[0046] A mixture of (E)-Ethyl 2-(3-(3,4-dimethylphenyl)acrylamido)-4,4-dimethylpentanoate (60 mg, 0.18 mmol), 1-methyl-4-(prop-1-ynyl)benzene (24 mg, 0.18 mmol), RhCp*(MeCN).sub.3(SbF.sub.6).sub.2 (7.5 mg, 0.01 mmol) and Cu(OAc).sub.2.H.sub.2O (152 mg, 0.76 mmol) in DCE (2 mL) was stirred at 100° C. After 24 h, the mixture was cooled down to ambient temperature and quenched with 10% NH.sub.3.H.sub.2O in saturated NH.sub.4Cl (aq.) and extracted with DCM (10 mL×3). The combined organic layers was washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=3:1) to afford the title compound as a yellow oil (50 mg, 60% yield). LC-MS (ESI): m/z (M+1)=460.5.

Step 3: 2-(4-(3,4-dimethylphenyl)-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoic acid

[0047] ##STR00019##

[0048] To a solution of Ethyl 2-(4-(3,4-dimethylphenyl)-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate (50 mg, 0.11 mmol) in MeOH (2 mL) was added 1 N NaOH (1.0 mL) and heated to reflux. After 12 h, the reaction mixture was cooled to ambient temperature, acidified with 1 N HCl (1.0 mL) (pH=6˜7) and concentrated under reduced pressure to give the crude product which was purified by reverse phase HPLC (C.sub.18 50˜100% CH.sub.3CN in H.sub.2O with 0.1% formic acid) to afford the title compound as a white powder (37 mg, 77% yield). .sup.1H NMR (400 MHz, DMSO) δ 12.86 (br, 1H), 7.57-6.99 (m, 7H), 6.24 (s, 1H), 4.27 (s, 1H), 2.39 (s, 3H), 2.36-2.15 (m, 7H), 1.96-1.79 (m, 1H), 1.58 (s, 3H), 0.61 (s, 9H). LC-MS (ESI): m/z (M+1)=432.4.

##STR00020##

Example 3

2-(4-(3,4-dimethylphenyl)-5-methyl-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoic acid

[0049] ##STR00021##

Step 1: Ethyl 2-(4-(3,4-dimethylphenyl)-5-methyl-3-nitro-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0050] ##STR00022##

[0051] To a mixture of Ethyl 2-(4-(3,4-dimethylphenyl)-5-methyl-2-oxo-6-p-tolylpyridin-1(2H)-yl)-4,4-dimethylpentanoate (153 mg, 0.33 mmol) and NaNO.sub.2 (28 mg, 0.37 mmol) in DCM (5 mL) was added TFA (0.5 mL) under O.sub.2 atmosphere. After 12 h, the reaction mixture was quenched with sat. NaHCO.sub.3 (aq.) and extracted with DCM (20 ml×3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=3:1) to afford the title compound as a yellow oil (140 mg, 83% yield). LC-MS (ESI): m/z (M+1)=505.3.

Step 2: Ethyl 2-(3-amino-4-(3,4-dimethylphenyl)-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0052] ##STR00023##

[0053] A mixture of Ethyl 2-(4-(3,4-dimethylphenyl)-5-methyl-3-nitro-2-oxo-6-p-tolylpyridin-1(2H)-yl)-4,4-dimethylpentanoate (140 mg, 0.28 mmol) and Pd/C (130 mg) in EtOAc (5 mL) was purged with H.sub.2 three times. After 2 h, the reaction mixture was filtered through Celite pad and the filtrate was concentrated under reduced pressure to afford the title compound as a yellow solid (133 mg, 99% yield). LC-MS (ESI): m/z (M+1)=475.4.

Step 3: Ethyl 2-(4-(3, 4-dimethylphenyl)-5-methyl-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0054] ##STR00024##

[0055] To a solution of Ethyl 2-(4-(3,4-dimethylphenyl)-5-methyl-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate (36 mg, 0.076 mmol) and DMAP (5 mg, 0.003 mmol) in pyridine (1 mL) was added MsCl (44 mg, 0.38 mmol). After 12 h, the reaction mixture was diluted with sat. NH.sub.4Cl (aq.) and extracted with EtOAc (10 ml×3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=2:1) to afford the title compound as a yellow oil (24 mg, 57% yield). LC-MS (ESI): m/z (M+1)=553.4.

Step 4: 2-(4-(3,4-Dimethylphenyl)-5-methyl-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoic acid

[0056] ##STR00025##

[0057] To a solution of Ethyl 2-(4-(3,4-dimethylphenyl)-5-methyl-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate (30 mg, 0.054 mmol) in MeOH (2 mL) was added 1 N NaOH (0.6 mL) and heated to reflux. After 12 h, the reaction mixture was cooled to ambient temperature, acidified with 1 N HCl (0.6 mL) (pH=6˜7) and concentrated under reduced pressure to give the crude product which was purified by reverse phase HPLC (C.sub.18 60˜100% CH.sub.3CN in H.sub.2O with 0.1% formic acid) to afford the title compound as a white powder (14 mg, 49% yield). .sup.1H NMR (400 MHz, DMSO) δ 12.93 (br, 1H), 8.30 (s, 1H), 7.51-7.27 (m, 4H), 7.28-7.16 (m, H), 7.08-6.92 (m, 2H), 4.31 (s, 1H), 2.91 (d, J=4.6 Hz, 3H), 2.41-2.31 (m, 4H), 2.31-2.18 (m, 6H), 1.94-1.86 (m, 1H), 1.41 (s, 3H), 0.61 (s, 9H). LC-MS (ESI): m/z (M+1)=525.8.

##STR00026##

Example 4

4,4-Dimethyl-2-(5-methyl-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoic acid

[0058] ##STR00027##

Step 1: Ethyl 2-acrylamido-4, 4-dimethylpentanoate

[0059] ##STR00028##

[0060] To a solution of Ethyl 2-amino-4,4-dimethylpentanoate (150 mg, 0.86 mmol) in DCM (4 mL) was added acryloyl chloride (156 mg, 1.72 mmol). After 1 h, the reaction mixture was diluted with sat. NaHCO.sub.3 (aq.) and extracted with DCM (20 ml×2). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, DCM:MeOH=20:1) to afford the title compound as a yellow solid (190 mg, 96% yield). LC-MS (ESI): m/z (M+1)=228.3.

Step 2: Ethyl 4,4-dimethyl-2-(5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoate

[0061] ##STR00029##

[0062] A mixture of Ethyl 2-acrylamido-4,4-dimethylpentanoate (200 mg, 0.18 mmol), 1-methyl-4-(prop-1-ynyl)benzene (250 mg, 0.35 mmol), RhCp*(MeCN).sub.3(SbF.sub.6).sub.2 (30 mg, 0.01 mmol) and Cu(OAc).sub.2.H.sub.2O (365 mg, 0.37 mmol) in DCE (4 mL) was stirred at 100° C. After 24 h, the mixture was cooled down to ambient temperature and quenched with 10% NH.sub.3.H.sub.2O in saturated NH.sub.4Cl (aq.) and extracted with DCM (10 mL×3). The combined organic layers was washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=2:1) to afford the title compound as a yellow oil (50 mg, 16% yield). LC-MS (ESI): m/z (M+1)=356.2.

Step 3: Ethyl 2-(3-bromo-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0063] ##STR00030##

[0064] To a solution of Ethyl 4,4-dimethyl-2-(5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoate (105 mg, 0.3 mmol) in CHCl.sub.3 (4 mL) was added NBS (61 mg, 0.33 mmol) and heated to 40° C. After 12 h, the reaction mixture was diluted with water and extracted with DCM (20 ml×2). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=5:1) to afford the title compound as a yellow oil (115 mg, 90% yield). LC-MS (ESI): m/z (M/M+2)=434.2/436.2.

Step 4: Ethyl 2-(3-((diphenylmethylene)amino)-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0065] ##STR00031##

[0066] A mixture of Ethyl 2-(3-bromo-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate (130 mg, 0.30 mmol), diphenylmethanimine (165 mg, 0.90 mmol), Pd.sub.2(dba).sub.3 (30 mg, 0.03 mmol), Xantphos (17 mg, 0.03 mmol) and Cs.sub.2CO.sub.3 (292 mg, 0.90 mmol) in dioxane (3 mL) was stirred at 90° C. under N.sub.2 atmosphere. After 20 h, the mixture was cooled down to ambient temperature, diluted with water and extracted with EtOAc (20 mL×3). The combined organic layers was washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=3:1) to afford the title compound as a yellow oil (100 mg, 63% yield). LC-MS (ESI): m/z (M+1)=535.3.

Step 5: Ethyl 2-(3-amino-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0067] ##STR00032##

[0068] To a solution of Ethyl 2-(3-((diphenylmethylene)amino)-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate (100 mg, 0.19 mmol) in MeOH (5 mL) was added 1 N HCl (1 mL). After 1 h, the reaction mixture was neutralized with sat. NaHCO.sub.3 (aq.) and extracted with DCM (20 ml×2). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=2:1) to afford the title compound as a yellow oil (53 mg, 77% yield). .sup.1H NMR (400 MHz, DMSO) δ 7.31 (t, J=6.9 Hz, 2H), 7.23 (dd, J=8.7, 7.1 Hz, 2H), 6.40 (s, 1H), 5.13 (s, 2H), 4.32 (s, 1H), 4.22-4.11 (m, 1H), 4.10-3.95 (m, 2H), 2.36 (s, 3H), 2.28-2.19 (m, 1H), 1.89-1.79 (m, 1H), 1.74 (s, 3H), 1.17 (q, J=7.1 Hz, 3H), 0.56 (s, 9H). LC-MS (ESI): m/z (M+1)=371.2.

Step 6: Ethyl 4,4-dimethyl-2-(5-methyl-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoate

[0069] ##STR00033##

[0070] To a solution of Ethyl 2-(3-amino-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpenta noate (13 mg, 0.035 mmol) and DMAP (1 mg, 0.008 mmol) in pyridine (2 mL) was added MsCl (12 mg, 0.105 mmol). After 1 h, the reaction mixture was quenched with sat. NH.sub.4Cl (aq.) and extracted with DCM (20 ml×2). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to afford the title compound as a yellow oil (53 mg, 77% yield) which was used in next step without further purification. LC-MS (ESI): m/z (M+1)=449.3.

Step 7: 4,4-Dimethyl-2-(5-methyl-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoic acid

[0071] ##STR00034##

[0072] To a solution of Ethyl 4,4-dimethyl-2-(5-methyl-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoate (15 mg, 0.033 mmol) in MeOH (3 mL) was added 1 N NaOH (0.3 mL) and heated to reflux. After 6 h, the reaction mixture was cooled to ambient temperature, acidified with 1 N HCl (0.3 mL) (pH=6˜7) and concentrated under reduced pressure to give the crude product which was purified by reverse phase HPLC (C.sub.18 60˜100% CH.sub.3CN in H.sub.2O with 0.1% formic acid) to afford the title compound as a white powder (7 mg, 50% yield). .sup.1H NMR (400 MHz, DMSO) δ 12.93 (br, 1H), 8.88 (s, 1H), 7.45-7.22 (m, 5H), 4.34 (s, 1H), 3.09 (s, 3H), 2.39 (s, 3H), 2.23 (dd, J=15.1, 3.7 Hz,1H), 1.98-1.91 (m, 1H), 1.81 (s, 3H), 0.57 (s, 9H). LC-MS (ESI): m/z (M+1)=421.2.

##STR00035## ##STR00036##

Example 5: 4,4-dimethyl-2-(5-methyl-4-(((1s,4s)-4-methylcyclohexyl)carbamoyl)-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoic acid

[0073] ##STR00037##

Step 1: Ethyl 2-(4-(((tert-butyldimethylsilyl)oxy)methyl)-5-methyl-3-nitro-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0074] ##STR00038##

[0075] To a mixture of Ethyl 2-(4-((tert-butyldimethylsilyloxy)methyl)-5-methyl-2-oxo-6-p-tolylpyridin-1(2H)-yl)-4,4-dimethylpentanoate (50 mg, 0.10 mmol), NaNO.sub.2 (7.5 mg, 0.11 mmol) in DCM (5 mL) was added TFA (0.05 mL) under O.sub.2 atmosphere. After 12 h, the reaction mixture was quenched with sat. NaHCO.sub.3 (aq.) and extracted with DCM (20 ml×3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=5:1) to afford the title compound as a yellow oil (54 mg, 92% yield). LC-MS (ESI): m/z (M+1)=545.6.

Step 2: Ethyl 2-(4-(hydroxymethyl)-5-methyl-3-nitro-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0076] ##STR00039##

[0077] To a solution of Ethyl 2-(4-(((tert-butyldimethylsilyl)oxy)methyl)-5-methyl-3-nitro-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate (138 mg, 0.25 mmol) in THF (10 mL) was added TBAF (133 mg, 0.51 mmol). After 30 min, the reaction mixture was partitioned between EtOAc and water. The layers were separated and the organic layer was washed with H.sub.2O and brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=2:1) to afford the title compound as a yellow oil (104 mg, 95% yield). LC-MS (ESI): m/z (M+1) 431.4.

Step 3: Ethyl 2-(4-formyl-5-methyl-3-nitro-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0078] ##STR00040##

[0079] To a solution of Ethyl 2-(4-(hydroxymethyl)-5-methyl-3-nitro-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate (33 mg, 0.08 mmol) in DCM (5 mL) was added DMP (49 mg, 0.12 mmol). After 1 h, the reaction mixture was quenched with NaHCO.sub.3(aq.) and extracted with DCM (20 ml×3). The combined organic layers was washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, DCM) to afford the title compound as a yellow solid (27 mg, 82% yield). LC-MS (ESI): m/z (M+1)=429.5.

Step 4: 1-(1-Ethoxy-4,4-dimethyl-1-oxopentan-2-yl)-5-methyl-3-nitro-2-oxo-6-(p-tolyl)-1,2-dihydropyridine-4-carboxylic acid

[0080] ##STR00041##

[0081] To a solution of Ethyl 2-(4-formyl-5-methyl-3-nitro-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethyl pentanoate (27 mg, 0.06 mmol) in THF (1 mL), t-BuOH (1 mL) and isobutylene (1 ml) in a sealed tube was added a solution of NaH.sub.2PO.sub.4 (59 mg, 0.38 mmol) and NaClO.sub.2 (46 mg, 0.50 mmol) in H.sub.2O (1 mL). After 12 h, the reaction mixture was acidified with 1 N HCl and extracted with EtOAc (20 ml×3). The combined organic layers was washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the title compound as a yellow solid (30 mg, 99% yield) which was used in next step without further purification. LC-MS (ESI): m/z (M+1)=445.5

Step 6: Ethyl 4,4-dimethyl-2-(5-methyl-4-(((1s,4s)-4-methylcyclohexyl)carbamoyl)-3-nitro-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoate

[0082] ##STR00042##

[0083] A solution of 1-(1-ethoxy-4,4-dimethyl-1-oxopentan-2-yl)-5-methyl-3-nitro-2-oxo-6-(p-toly)-1,2-dihydropyridine-4-carboxylic acid (30 mg, 0.067 mmol) in DMF (3 mL) was treated with DIPEA (35 mg, 0.27 mmol), HBTU (52 mg, 0.13 mmol) and trans-4-methyl cyclohexyl amine (15 mg, 0.14 mmol). After 30min, the reaction mixture was diluted with water and extracted with EtOAc (20 ml×3). The combined organic layers was washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=2:1) to afford the title compound as a yellow oil (18 mg, 50%). LC-MS (ESI): m/z (M+1)=540.8.

Step 7: Ethyl 2-(3-amino-5-methyl-4-(((1s,4s)-4-methylcyclohexyl)carbamoyl)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl-4,4-dimethylpentanoate

[0084] ##STR00043##

[0085] A mixture of Ethyl 4,4-dimethyl-2-(5-methyl-4-(((1s,4s)-4-methylcyclohexyl)carbamoyl)-3-nitro-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoate (18 mg, 0.03 mmol) and Pd/C (10 mg) in EtOAc (5 mL) was purged with H.sub.2 three times. After 12 h, the reaction mixture was filtered through Celite pad and the filtrate was concentrated under reduced pressure to afford the title compound as a yellow solid (10 mg, 65% yield). LC-MS (ESI): m/z (M+1)=510.6.

Step 8: Ethyl 4,4-dimethyl-2-(5-methyl-4-(((1s,4s)-4-methylcyclohexyl)carbamoyl)-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoate

[0086] ##STR00044##

[0087] To a solution of Ethyl 2-(3-amino-5-methyl-4-(((1s,4s)-4-methylcyclohexyl)carbamoyl)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate (19 mg, 0.037 mmol) and DMAP (1 mg, 0.008 mmol) in pyridine (2 mL) was added MsCl (0.03 mL, 0.37 mmol). After 2 h, the reaction mixture was diluted with water and extracted with EtOAc (20 ml×2). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=2:1) to afford the title compound as a yellow oil (5 mg, 23% yield). LC-MS (ESI): m/z (M+1)=588.7.

Step 9: 4,4-Dimethyl-2-(5-methyl-4-(((1s,4s)-4-methylcyclohexyl)carbamoyl)-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoic acid

[0088] ##STR00045##

[0089] To a solution of Ethyl 4,4-dimethyl-2-(5-methyl-4-(((1s,4s)-4-methylcyclohexyl)carbamoyl)-3-(methylsulfonamido)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoate (5 mg, 0.008 mmol) in MeOH (2 mL) was added 1 N NaOH (0.2 mL) and heated to reflux. After 12 h, the reaction mixture was cooled to ambient temperature, acidified with 1 N HCl (0.2 mL) (pH=6˜7) and concentrated under reduced pressure to give the crude product which was purified by reverse phase HPLC (C.sub.18 10˜100% CH.sub.3CN in H.sub.2O with 0.1% formic acid) to afford the title compound as a white powder (3 mg, 67% yield). .sup.1H NMR (400 MHz, DMSO) δ 8.33 (s, 1H), 7.87 (d, J=7.2 Hz, 1H), 7.48-7.34 (m, 3H), 7.26 (d, J=7.6 Hz, 1H), 4.19 (s, 1H), 3.65-3.61 (m, 1H), 3.14 (s, 3H), 2.39 (s, 3H), 2.31-2.26 (m, 1H), 1.93-1.80 (m, 3H), 1.75-1.56 (m, 5H), 1.32-1.20 (m, 3H), 1.03-0.94 (m, 2H), 0.87 (d, J=6.4 Hz, 3H), 0.57 (s, 9H). LC-MS (ESI): m/z (M+1)=560.6.

##STR00046##

Example 6: 4,4-Dimethyl-2-(5-methyl-4-(5-(((1 r,4r)-4-methylcyclohexyl)amino)-1,3,4-oxadiazol-2-yl)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoic acid

[0090] ##STR00047##

Step 1: Ethyl 2-(4-(hydrazinecarbonyl)-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate

[0091] ##STR00048##

[0092] To a solution of 1-(1-ethoxy-4,4-dimethyl-1-oxopentan-2-yl)-5-methyl-2-oxo-6-p-tolyl-1,2-dihydropyridine-4-carboxylic acid (66 mg, 0.165 mmol) in THF (3 mL) was added CDl (107 mg, 0.66 mmol). After 30min, hydrazine (0.1 mL, 1.65 mmol) was added and stirred for 1h. The reaction mixture was concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, DCM:MeOH=10:1) to afford the title compound as a colorless oil (44 mg, 64% yield). LC-MS (ESI): m/z (M+1)=414.4.

Step 2: Ethyl 4,4-dimethyl-2-(5-methyl-2-oxo-4-(5-oxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)-6-(p-tolyl)pyridin-1(2H)-yl)pentanoate

[0093] ##STR00049##

[0094] To a solution of Ethyl 2-(4-(hydrazinecarbonyl)-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoate (44 mg, 0.11 mmol) and DIPEA (0.04 mL, 0.22 mmol) in DCM (2 mL) was added triphosgene (13 mg, 0.04 mmol). After 30 min, the reaction mixture was quenched with water and extracted with DCM (20 ml×2). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=1:1) to afford the title compound as a yellow oil (46 mg, 100% yield). LC-MS (ESI): m/z (M+1)=440.4.

Step 3: Ethyl 4,4-dimethyl-2-(5-methyl-4-(5-(((1r,4r)-4-methylcyclohexyl)amino)-1,3,4-oxadiazol-2-yl)-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)pentanoate

[0095] ##STR00050##

[0096] A mixture of Ethyl 4,4-dimethyl-2-(5-methyl-2-oxo-4-(5-oxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)-6-(p-tolyl)pyridin-1(2H)-yl)pentanoate (25 mg, 0.06 mmol), (1r,4r)-4-methylcyclohexanamine (0.015 mL, 0.11 mmol), BOP (28 mg, 0.063 mmol) and DIPEA (0.02 mL, 0.11 mmol) in DMF (2 mL) was stirred at ambient temperature for 12 h. The reaction mixture was diluted with water and extracted with EtOAc (20 ml×2). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography (silica gel, PE:EA=1:1) to afford the title compound as a yellow oil (20 mg, 66% yield). LC-MS (ESI): m/z (M+1)=535.6.

Step 4: 4,4-Dimethyl-2-(5-methyl-4-(5-(((1r,4r)-4-methylcyclohexyl)amino)-1,3,4-oxadiazol-2-yl)-2-oxo-6-(p-tolyl)pyridin-1 (2H)-yl)pentanoic acid

[0097] ##STR00051##

[0098] To a solution of Ethyl 4,4-dimethyl-2-(5-methyl-4-(5-(((1r4r)-4-methylcyclohexyl)amino)-1,3,4-oxadiazol-2-yl)-2-oxo-6-(p-toly)pyridin-1(2H)-yl)pentanoate (20 mg, 0.037 mmol) in MeOH (2 mL) was added 1 N NaOH (0.4 mL) and heated to reflux. After 12 h, the reaction mixture was cooled to ambient temperature, acidified with 1 N HCl (0.4 mL) (pH=6˜) and concentrated under reduced pressure to give the crude product which was purified by reverse phase HPLC (C.sub.18 60˜100% CH.sub.3CN in H.sub.2O with 0.1% formic acid) to afford the title compound as a white powder (8 mg, 42% yield). .sup.1H NMR (400 MHz, DMSO) δ 12.86 (s, 1H), 7.96 (d, J=7.5 Hz, 1H), 7.45-7.30 (m, 4H), 6.75 (s, 1H), 4.28 (s, 1H), 3.39-3.36 (m, 1H), 2.41 (s, 3H), 2.26-2.22 (m, 1H), 2.06-1.93 (m, 5H), 1.92-1.87 (m, 1H), 1.75-1.68 (m, 2H), 1.37-1.27 (m, 3H), 1.08-1.01 (m, 2H), 0.89 (d, J=6.5 Hz, 3H), 0.59 (s, 9H). LC-MS (ESI): m/z (M+1)=507.6.

[0099] The following compounds were prepared in a manner simialar to the procedures described above for examples 1-6.

Example 7

2-(4-(cyclohexylcarbamoyl)-5-methyl-2-oxo-6-p-tolylpyridin-1(2H)-yl)-4,4-dimethylpentanoic acid

[0100] ##STR00052##

[0101] .sup.1H NMR (400 MHz, DMSO) δ=12.78 (br, 1H), 8.47 (d, J=8.0 Hz, 1H), 7.36 (m, 4H), 6.27 (s, 1H), 4.22 (s, 1H), 3.71-3.63 (m, 1H), 2.39 (s, 3H), 2.32-2.26 (m, 1H), 1.84-1.64 (m, 7H), 1.60-1.54 (m, 1H), 1.34-1.06 (m, 6H), 0.58 (s, 9H). LC-MS (ESI): m/z (M+1)=453.6

Example 8

2-(4-(cyclohexylmethylcarbamoyl)-5-methyl-2-oxo-6-p-tolylpyridin-1(2H)-yl)-4,4-dimethylpentanoic acid

[0102] ##STR00053##

[0103] .sup.1H NMR (400 MHz, DMSO) δ=12.92 (br, 1H), 8.57 (t, J=5.9 Hz, 1H), 7.42-7.28 (m, 4H), 6.29 (s, 1H), 4.23 (s, 1H), 3.08-3.01 (m, 2H), 2.39 (s,3H), 2.32-2.24 (m, 1H), 1.90-1.80 (m, 1H), 1.74-1.58 (m, 8H), 1.52-1.44 (m, 1H), 1.24-1.13 (m, 3H), 0.96-0.86 (m, 2H), 0.59 (s, 9H). LC-MS (ESI): m/z (M+1)=467.6

Example 9

2-(4-(benzylcarbamoyl)-5-methyl-2-oxo-6-p-tolylpyridin-1(2H)-yl)-4,4-dimethylpentanoic acid

[0104] ##STR00054##

[0105] .sup.1H NMR (400 MHz, DMSO) δ 12.86 (br, 1H), 9.15 (t, J=5.8 Hz, 1H), 7.67-6.96 (m, 9H), 6.38 (s, 1H), 4.41 (d, J=4.7 Hz, 2H), 4.25 (s, 1H), 2.39 (s, 3H), 2.32-2.22 (m, 1H), 1.92-1.78 (m, 1H), 1.67 (s, 3H), 0.59 (s, 9H). LC-MS (ESI): m/z (M+1)=461.3

Example 10

2-(3-(cyclohexylmethylsulfonamido)-5-methyl-2-oxo-6-(p-tolyl)pyridin-1(2H)-yl)-4,4-dimethylpentanoic acid

[0106] ##STR00055##

[0107] 1H NMR (400 MHz, DMSO) δ 12.93 (br, 1H), 8.82 (s, 1H), 7.46-7.25 (m, 5H), 4.31 (s, 1H), 3.05 (d, J=6.1 Hz, 2H), 2.39 (s, 3H), 2.25-2.19 (m, 1H), 2.04-1.97 (m, 1H), 1.92-1.78 (m, 5H), 1.68-1.56 (m, 3H), 1.24-0.99 (m, 5H), 0.56 (s, 9H). LC-MS (ESI): m/z (M+1)=503.3

Example 11

2-(6-(8-fluoro-5-methylchroman-6-yl)-5-methyl-4-(((1s,4s)-4-methylcyclohexyl)carbamoyl)-2-oxopyridin-1(2H)-yl)-4,4-dimethylpentanoic acid

[0108] ##STR00056##

[0109] 1H NMR (400 MHz, DMSO) δ 8.45 (d, J=8.1 Hz, 1H), 7.03-6.84 (m, 1H), 6.23 (s, 1H), 4.23-4.15 (m, 3H), 3.61-3.55 (m, 1H), 2.72-2.56 (m, 2H), 2.42-2.32 (m, 1H), 2.05-1.88 (m, 5H), 1.85-1.75 (m, 2H), 1.71-1.62 (m,2H), 1.55 (d, J=24.2 Hz, 3H), 1.33-1.16 (m, 4H), 1.03-0.91 (m, 2H), 0.85 (d, J=6.5 Hz, 3H), 0.61 (d, J=33.7 Hz, 9H). LC-MS (ESI): m/z (M+1)=541.9

Biological Examples

Anti-HIV Activity

MT4 Assay

[0110] Antiviral HIV activity and cytotoxicity values for compounds of the invention from Table 1 were measured in parallel in the HTLV-1 transformed cell line MT-4 based on the method previously described (Hazen et al., 2007, In vitro antiviral activity of the novel, tyrosyl-based human immunodeficiency virus (HIV) type 1 protease inhibitor brecanavir (GW640385) in combination with other antiretrovirals and against a panel of protease inhibitor-resistant HIV (Hazen et al., “In vitro antiviral activity of the novel, tyrosyl-based human immunodeficiency virus (HIV) type 1 protease inhibitor brecanavir (GW640385) in combination with other antiretrovirals and against a panel of protease inhibitor-resistant HIV”, Antimicrob. Agents Chemother. 2007, 51: 3147-3154; and Pauwels et al., “Sensitive and rapid assay on MT-4 cells for the detection of antiviral compounds against the AIDS virus”, J. of Virological Methods 1987, 16: 171-185).

[0111] Luciferase activity was measured 96 hours later by adding a cell titer glo (Promega, Madison, Wis.). Percent inhibition of cell protection data was plotted relative to no compound control. Under the same condition, cytotoxicity of the compounds was determined using cell titer Glo™ (Promega, Madison, Wis). IC.sub.50s were determined from a 10 point dose response curve using 3-4-fold serial dilution for each compound, which spans a concentration range >1000 fold.

[0112] These values are plotted against the molar compound concentrations using the standard four parameter logistic equation:

y=((Vmax*x{circumflex over (n)}n)/(K{circumflex over (n)}+x{circumflex over (n)}))+Y2

[0113] where:

[0114] Y2=minimum y n=slope factor

[0115] Vmax=maximum y x=compound concentration [M]

[0116] K=EC.sub.50

[0117] When tested in the MT4 assay compounds were found to have IC.sub.50 values listed in Table 2.

TABLE-US-00001 TABLE 2 HIV MT4 Assay IC.sub.50 Example (uM) 1 0.35 2 1.09 3 0.31 4 33 5 6 5.6 7 0.43 8 0.84 9 3.29 10 1.56 11