TERT-BUTYL 3-(ETHOXYCARBONYL)-2-OXOPROPYLCARBAMATE

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 25-mL round-bottomed flask was added ethyl 4-((tert-butoxycarbonyl)amino)-3-oxobutanoate (601) (0.60 g, 2.44 mmol), K2CO3 (0.56 g, 4.07 mmol), 2-bromo-1-(2-methyl-3-((1-methylcyclopropyl)amino)quinoxalin-5-yl)ethanone (611) (0.54 g, 1.63 mmol), THF (6 mL), and EtOH (6 mL). The reaction mixture was stirred at RT for 16 h and diluted with sat NH4Cl (5 mL) and extracted with EtOAc (10 mL). The organic extract was washed with water (5 mL), dried over Na2SO4 and concentrated. Ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(2-methyl-3-((1-methylcyclopropyl)amino)quinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (357a) was obtained as a light yellow oil and used without further purification. m/z (ESI, +ve) 499.2 (M+H)+. To a 15-mL glass tube was added ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(2-methyl-3-((1-methylcyclopropyl)amino)quinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (357a), crude from previous step, NH4OAc (0.50 g, 6.51 mmol), EtOH (3 mL), and AcOH (1 mL). The tube was sealed and heated at 50° C. for 3 h. The reaction mixture was cooled to RT and was concentrated to half of its volume. The mixture was diluted with EtOAc (10 mL) and water (5 mL). The organic extract was washed with NaOH (1 N, 5 mL), water (5 mL), brine (5 mL), dried over Na2SO4, and concentrated. The crude material was absorbed onto a plug of silica gel and purified by chromatography through a Redi-Sep pre-packed silica gel column (24 g), eluting with a gradient of 10% to 30% EtOAc in hexanes to give ethyl 2-4(tert-butoxycarbonyl)amino)methyl)-5-(2-methyl-3-((1-methylcyclopropyl)amino)quinoxalin-5-yl)-1H-pyrrole-3-carboxylate (357b) (0.25 g, 32% yield) as a yellow solid. 1H NMR (400 MHz, DMSO-d6) δ 12.24 (br. s., 1H), 7.97 (dd, J=1.17, 7.63 Hz, 1H), 7.54-7.63 (m, 3H), 7.34 (t, J=7.82 Hz, 1H), 6.94 (br. s., 1H), 4.51 (d, J=5.28 Hz, 2H), 4.22 (q, J=7.17 Hz, 2H), 2.48 (s, 3H), 1.56 (s, 3H), 1.38 (s, 9H), 1.29 (t, J=7.00 Hz, 3H), 0.91-0.94 (m, 2H), 0.84-0.89 (m, 2H). m/z (ESI, +ve) 480.4 (M+H)+. extracted with EtOAc (10 mL) The organic extract was washed with water (5 mL) dried over Na2SO4 concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 25-mL round-bottomed flask was added ethyl 4-((tert-butoxycarbonyl)amino)-3-oxobutanoate (601) (0.47 g, 1.91 mmol), K2CO3 (0.41 g, 2.97 mmol), 2-bromo-1-(3-(tert-butylamino)-2-methylquinoxalin-5-yl)ethanone (606) (0.40 g, 1.19 mmol), THF (3 mL), and EtOH (3 mL). The reaction mixture was stirred at RT for 16 h. The reaction mixture was diluted with sat NH4Cl (5 mL) and extracted with EtOAc (10 mL). The organic extract was washed with water (5 mL), dried over Na2SO4 and concentrated. Ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(3-(tert-butylamino)-2-methylquinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (334a) was obtained as a light yellow oil and used without further purification. m/z (ESI, +ve) 501.3 (M+H)+. To a 15-mL glass tube was added ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(3-(tert-butylamino)-2-methylquinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (334a), crude from previous step, NH4OAc (0.36 g, 4.71 mmol), EtOH (2 mL), and AcOH (1 mL). The tube was sealed and heated at 50° C. for 3 h. The reaction mixture was cooled to RT and was concentrated to half of its volume. The mixture was diluted with EtOAc (10 mL) and water (5 mL). The organic extract was washed with NaOH (1N, 5 mL), water (5 mL), brine (5 mL), dried over Na2SO4, and concentrated. The crude material was absorbed onto a plug of silica gel and purified by chromatography through a Redi-Sep pre-packed silica gel column (24 g), eluting with a gradient of 0% to 30% EtOAc in hexanes to give ethyl 2-(((tert-butoxycarbonyl)amino)methyl)-5-(3-(tert-butylamino)-2-methylquinoxalin-5-yl)-1H-pyrrole-3-carboxylate (334b) (0.33 g, 59% yield) as a yellow solid. 1H NMR (400 MHz, DMSO-d6) δ 11.64 (br. s., 1H), 7.82 (dd, J=1.17, 7.43 Hz, 1H), 7.58-7.64 (m, 1H), 7.41 (d, J=2.74 Hz, 1H), 7.35 (s, 1H), 6.94 (br. s., 1H), 4.53 (d, J=5.28 Hz, 2H), 4.21 (q, J=7.04 Hz, 2H), 2.56 (s, 3H), 1.58 (s, 9H), 1.39 (s, 9H), 1.30 (t, J=7.10 Hz, 3H). m/z (ESI, +ve) 482.2 (M+H)+. extracted with EtOAc (10 mL) The organic extract was washed with water (5 mL) dried over Na2SO4 concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This compound (380 mg, 0.75 mmol, 55% yield) as a yellow solid was prepared according to the procedure described for 293b, using 2-bromo-1-(2-methyl-3-((2,2,2-trifluoroethyl)amino)quinoxalin-5-yl)ethanone (616) (492 mg, 1.36 mmol), ethyl 4-((tert-butoxycarbonyl)amino)-3-oxobutanoate (601) (400 mg, 1.63 mmol) and K2CO3 (0.21 mL, 3.40 mmol) in DMF (2.75 mL), followed by subsequent treatment of the resulting ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(2-methyl-3-((2,2,2-trifluoroethyl)amino)quinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (301a) (530 mg, m/z (ESI, +ve) 527.2 (M+H)+) with NH4OAc (838 mg, 10.87 mmol) in 2 mL of EtOH and AcOH (1 mL) at 60° C. overnight. 1H NMR (400 MHz, CDCl3) δ ppm 7.92-7.98 (m, 1H), 7.68-7.74 (m, 1H), 7.44 (t, J=7.92 Hz, 1H), 7.11 (d, J=2.74 Hz, 1H), 5.44 (br. s., 1H), 5.18 (t, J=6.26 Hz, 1H), 4.56-4.65 (m, 2H), 4.54 (d, J=6.46 Hz, 2H), 4.33 (q, J=7.17 Hz, 2H), 2.63 (s, 3H), 1.35-1.43 (m, 12H). 19F NMR (376 MHz, CDCl3) δ ppm −70.89 (s, 3F). m/z (ESI, +ve) 508.1 (M+H)+.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This compound (873 mg, 34% yield) as a yellow foam was prepared according to the procedure described for intermediate 293b, using 2-bromo-1-(3-(tert-butylamino)-6-fluoro-2-methylquinoxalin-5-yl)ethanone (605) (1.81 g, 5.11 mmol), ethyl 4-((tert-butoxycarbonyl)amino)-3-oxobutanoate (601) (1.50 g, 6.13 mmol) and K2CO3 (1.77 g, 12.77 mmol) in DMF (17 mL) was stirred at RT for 6 h, followed by the subsequent treatment of the resulting ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(3-(tert-butylamino)-6-fluoro-2-methylquinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (296a) (1.43 g, 2.76 mmol, 54% yield, m/z (ESI, +ve) 519.2 (M+H)+) with NH4Oac (3.15 g, 40.9 mmol) in 12 mL of EtOH and AcOH (6 mL). 1H NMR (400 MHz, CDCl3) δ ppm 7.63 (dd, J=8.80, 5.67 Hz, 1H), 7.34 (dd, J=4.60, 2.45 Hz, 1H), 7.21 (dd, J=11.64, 8.90 Hz, 1H), 4.94 (s, 1H), 4.62 (d, J=5.87 Hz, 2H), 4.34 (q, J=7.24 Hz, 2H), 2.54 (s, 3H), 1.69 (s, 9H), 1.43 (s, 9H), 1.38-1.42 (m, 3H). 19F NMR (376 MHz, CDCl3) δ ppm −107.37 (s, 1F). m/z (ESI, +ve) 500.1 (M+H)+.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A tautomeric mixture of ethyl 3-(1-((tert-butoxycarbonyl)amino)cyclopropyl)-3-oxopropanoate and (Z)-ethyl 3-(1-((tert-butoxycarbonyl)amino)cyclopropyl)-3-hydroxyacrylate (3.15 g, 11.61 mmol, 90% yield) as an off white solid was prepared according the procedures described for Intermediate 601, using 1-(Boc-amino)cyclopropanecarboxylic acid (Chem-Impex International, Inc., cat #04052) (2.59 g, 12.87 mmol) as the reagent. m/z (ESI, +ve) 294.2 (M+23)+. was prepared

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Referenced: J. Med. Chem. 2008, 51 (3), 487-501. At RT, 1,1′-carbonyldiimidazole (13.88 g, 86 mmol) was added to a solution of N-Boc-glycine (Sigma-Aldrich Chemical Company, Inc.) (10.00 g, 57.1 mmol) in THF (200 mL) and the mixture was stirred for 3 h. Magnesium chloride (10.87 g, 114 mmol) and potassium ethyl malonate (Sigma-Aldrich Chemical Company, Inc.) (19.43 g, 114 mmol) were added and the resulting suspension was heated in an oil bath at 50° C. for 18 h. The reaction mixture was concentrated under reduced pressure. The off-white residue was treated with EtOAc (300 mL), then washed sequentially with 5% sodium bisulfate (2×25 mL), saturated NaHCO3 (2×50 mL), and brine (25 mL). The organic layer was dried over anhydrous Na2SO4, filtered and concentrated. The crude material was purified by chromatography through a Thomson Single Step pre-packed silica gel column (160 g, eluted with a gradient of 0-75% EtOAc in hexanes) to provide ethyl 4-((tert-butoxycarbonyl)amino)-3-oxobutanoate (10.33 g, 42.1 mmol, 74% yield) as a colorless viscous oil after drying under vacuum overnight. 1H NMR (400 MHz, CDCl3) δ ppm 5.16 (1H, d, J=5.7 Hz), 4.21 (2H, m), 4.08-4.16 (2H, m), 3.48 (2H, s), 1.45 (9H, s), 1.29 (3H, m). m/z (ESI, +ve) 268.0 (M+Na)+. The reaction mixture was concentrated under reduced pressure The off-white residue was treated with EtOAc (300 mL) washed sequentially with 5% sodium bisulfate (2×25 mL), saturated NaHCO3 (2×50 mL), and brine (25 mL) The organic layer was dried over anhydrous Na2SO4 filtered concentrated The crude material was purified by chromatography through a Thomson Single Step pre-packed silica gel column (160 g eluted with a gradient of 0-75% EtOAc in hexanes)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 25-mL round-bottomed flask was added ethyl 4-((tert-butoxycarbonyl)amino)-3-oxobutanoate (601) (0.60 g, 2.44 mmol), K2CO3 (0.56 g, 4.07 mmol), 2-bromo-1-(2-methyl-3-((1-methylcyclopropyl)amino)quinoxalin-5-yl)ethanone (611) (0.54 g, 1.63 mmol), THF (6 mL), and EtOH (6 mL). The reaction mixture was stirred at RT for 16 h and diluted with sat NH4Cl (5 mL) and extracted with EtOAc (10 mL). The organic extract was washed with water (5 mL), dried over Na2SO4 and concentrated. Ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(2-methyl-3-((1-methylcyclopropyl)amino)quinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (357a) was obtained as a light yellow oil and used without further purification. m/z (ESI, +ve) 499.2 (M+H)+. To a 15-mL glass tube was added ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(2-methyl-3-((1-methylcyclopropyl)amino)quinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (357a), crude from previous step, NH4OAc (0.50 g, 6.51 mmol), EtOH (3 mL), and AcOH (1 mL). The tube was sealed and heated at 50° C. for 3 h. The reaction mixture was cooled to RT and was concentrated to half of its volume. The mixture was diluted with EtOAc (10 mL) and water (5 mL). The organic extract was washed with NaOH (1 N, 5 mL), water (5 mL), brine (5 mL), dried over Na2SO4, and concentrated. The crude material was absorbed onto a plug of silica gel and purified by chromatography through a Redi-Sep pre-packed silica gel column (24 g), eluting with a gradient of 10% to 30% EtOAc in hexanes to give ethyl 2-4(tert-butoxycarbonyl)amino)methyl)-5-(2-methyl-3-((1-methylcyclopropyl)amino)quinoxalin-5-yl)-1H-pyrrole-3-carboxylate (357b) (0.25 g, 32% yield) as a yellow solid. 1H NMR (400 MHz, DMSO-d6) δ 12.24 (br. s., 1H), 7.97 (dd, J=1.17, 7.63 Hz, 1H), 7.54-7.63 (m, 3H), 7.34 (t, J=7.82 Hz, 1H), 6.94 (br. s., 1H), 4.51 (d, J=5.28 Hz, 2H), 4.22 (q, J=7.17 Hz, 2H), 2.48 (s, 3H), 1.56 (s, 3H), 1.38 (s, 9H), 1.29 (t, J=7.00 Hz, 3H), 0.91-0.94 (m, 2H), 0.84-0.89 (m, 2H). m/z (ESI, +ve) 480.4 (M+H)+. extracted with EtOAc (10 mL) The organic extract was washed with water (5 mL) dried over Na2SO4 concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 25-mL round-bottomed flask was added ethyl 4-((tert-butoxycarbonyl)amino)-3-oxobutanoate (601) (0.47 g, 1.91 mmol), K2CO3 (0.41 g, 2.97 mmol), 2-bromo-1-(3-(tert-butylamino)-2-methylquinoxalin-5-yl)ethanone (606) (0.40 g, 1.19 mmol), THF (3 mL), and EtOH (3 mL). The reaction mixture was stirred at RT for 16 h. The reaction mixture was diluted with sat NH4Cl (5 mL) and extracted with EtOAc (10 mL). The organic extract was washed with water (5 mL), dried over Na2SO4 and concentrated. Ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(3-(tert-butylamino)-2-methylquinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (334a) was obtained as a light yellow oil and used without further purification. m/z (ESI, +ve) 501.3 (M+H)+. To a 15-mL glass tube was added ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(3-(tert-butylamino)-2-methylquinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (334a), crude from previous step, NH4OAc (0.36 g, 4.71 mmol), EtOH (2 mL), and AcOH (1 mL). The tube was sealed and heated at 50° C. for 3 h. The reaction mixture was cooled to RT and was concentrated to half of its volume. The mixture was diluted with EtOAc (10 mL) and water (5 mL). The organic extract was washed with NaOH (1N, 5 mL), water (5 mL), brine (5 mL), dried over Na2SO4, and concentrated. The crude material was absorbed onto a plug of silica gel and purified by chromatography through a Redi-Sep pre-packed silica gel column (24 g), eluting with a gradient of 0% to 30% EtOAc in hexanes to give ethyl 2-(((tert-butoxycarbonyl)amino)methyl)-5-(3-(tert-butylamino)-2-methylquinoxalin-5-yl)-1H-pyrrole-3-carboxylate (334b) (0.33 g, 59% yield) as a yellow solid. 1H NMR (400 MHz, DMSO-d6) δ 11.64 (br. s., 1H), 7.82 (dd, J=1.17, 7.43 Hz, 1H), 7.58-7.64 (m, 1H), 7.41 (d, J=2.74 Hz, 1H), 7.35 (s, 1H), 6.94 (br. s., 1H), 4.53 (d, J=5.28 Hz, 2H), 4.21 (q, J=7.04 Hz, 2H), 2.56 (s, 3H), 1.58 (s, 9H), 1.39 (s, 9H), 1.30 (t, J=7.10 Hz, 3H). m/z (ESI, +ve) 482.2 (M+H)+. extracted with EtOAc (10 mL) The organic extract was washed with water (5 mL) dried over Na2SO4 concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This compound (380 mg, 0.75 mmol, 55% yield) as a yellow solid was prepared according to the procedure described for 293b, using 2-bromo-1-(2-methyl-3-((2,2,2-trifluoroethyl)amino)quinoxalin-5-yl)ethanone (616) (492 mg, 1.36 mmol), ethyl 4-((tert-butoxycarbonyl)amino)-3-oxobutanoate (601) (400 mg, 1.63 mmol) and K2CO3 (0.21 mL, 3.40 mmol) in DMF (2.75 mL), followed by subsequent treatment of the resulting ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(2-methyl-3-((2,2,2-trifluoroethyl)amino)quinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (301a) (530 mg, m/z (ESI, +ve) 527.2 (M+H)+) with NH4OAc (838 mg, 10.87 mmol) in 2 mL of EtOH and AcOH (1 mL) at 60° C. overnight. 1H NMR (400 MHz, CDCl3) δ ppm 7.92-7.98 (m, 1H), 7.68-7.74 (m, 1H), 7.44 (t, J=7.92 Hz, 1H), 7.11 (d, J=2.74 Hz, 1H), 5.44 (br. s., 1H), 5.18 (t, J=6.26 Hz, 1H), 4.56-4.65 (m, 2H), 4.54 (d, J=6.46 Hz, 2H), 4.33 (q, J=7.17 Hz, 2H), 2.63 (s, 3H), 1.35-1.43 (m, 12H). 19F NMR (376 MHz, CDCl3) δ ppm −70.89 (s, 3F). m/z (ESI, +ve) 508.1 (M+H)+.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This compound (873 mg, 34% yield) as a yellow foam was prepared according to the procedure described for intermediate 293b, using 2-bromo-1-(3-(tert-butylamino)-6-fluoro-2-methylquinoxalin-5-yl)ethanone (605) (1.81 g, 5.11 mmol), ethyl 4-((tert-butoxycarbonyl)amino)-3-oxobutanoate (601) (1.50 g, 6.13 mmol) and K2CO3 (1.77 g, 12.77 mmol) in DMF (17 mL) was stirred at RT for 6 h, followed by the subsequent treatment of the resulting ethyl 4-((tert-butoxycarbonyl)amino)-2-(2-(3-(tert-butylamino)-6-fluoro-2-methylquinoxalin-5-yl)-2-oxoethyl)-3-oxobutanoate (296a) (1.43 g, 2.76 mmol, 54% yield, m/z (ESI, +ve) 519.2 (M+H)+) with NH4Oac (3.15 g, 40.9 mmol) in 12 mL of EtOH and AcOH (6 mL). 1H NMR (400 MHz, CDCl3) δ ppm 7.63 (dd, J=8.80, 5.67 Hz, 1H), 7.34 (dd, J=4.60, 2.45 Hz, 1H), 7.21 (dd, J=11.64, 8.90 Hz, 1H), 4.94 (s, 1H), 4.62 (d, J=5.87 Hz, 2H), 4.34 (q, J=7.24 Hz, 2H), 2.54 (s, 3H), 1.69 (s, 9H), 1.43 (s, 9H), 1.38-1.42 (m, 3H). 19F NMR (376 MHz, CDCl3) δ ppm −107.37 (s, 1F). m/z (ESI, +ve) 500.1 (M+H)+.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A tautomeric mixture of ethyl 3-(1-((tert-butoxycarbonyl)amino)cyclopropyl)-3-oxopropanoate and (Z)-ethyl 3-(1-((tert-butoxycarbonyl)amino)cyclopropyl)-3-hydroxyacrylate (3.15 g, 11.61 mmol, 90% yield) as an off white solid was prepared according the procedures described for Intermediate 601, using 1-(Boc-amino)cyclopropanecarboxylic acid (Chem-Impex International, Inc., cat #04052) (2.59 g, 12.87 mmol) as the reagent. m/z (ESI, +ve) 294.2 (M+23)+. was prepared

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Referenced: J. Med. Chem. 2008, 51 (3), 487-501. At RT, 1,1′-carbonyldiimidazole (13.88 g, 86 mmol) was added to a solution of N-Boc-glycine (Sigma-Aldrich Chemical Company, Inc.) (10.00 g, 57.1 mmol) in THF (200 mL) and the mixture was stirred for 3 h. Magnesium chloride (10.87 g, 114 mmol) and potassium ethyl malonate (Sigma-Aldrich Chemical Company, Inc.) (19.43 g, 114 mmol) were added and the resulting suspension was heated in an oil bath at 50° C. for 18 h. The reaction mixture was concentrated under reduced pressure. The off-white residue was treated with EtOAc (300 mL), then washed sequentially with 5% sodium bisulfate (2×25 mL), saturated NaHCO3 (2×50 mL), and brine (25 mL). The organic layer was dried over anhydrous Na2SO4, filtered and concentrated. The crude material was purified by chromatography through a Thomson Single Step pre-packed silica gel column (160 g, eluted with a gradient of 0-75% EtOAc in hexanes) to provide ethyl 4-((tert-butoxycarbonyl)amino)-3-oxobutanoate (10.33 g, 42.1 mmol, 74% yield) as a colorless viscous oil after drying under vacuum overnight. 1H NMR (400 MHz, CDCl3) δ ppm 5.16 (1H, d, J=5.7 Hz), 4.21 (2H, m), 4.08-4.16 (2H, m), 3.48 (2H, s), 1.45 (9H, s), 1.29 (3H, m). m/z (ESI, +ve) 268.0 (M+Na)+. The reaction mixture was concentrated under reduced pressure The off-white residue was treated with EtOAc (300 mL) washed sequentially with 5% sodium bisulfate (2×25 mL), saturated NaHCO3 (2×50 mL), and brine (25 mL) The organic layer was dried over anhydrous Na2SO4 filtered concentrated The crude material was purified by chromatography through a Thomson Single Step pre-packed silica gel column (160 g eluted with a gradient of 0-75% EtOAc in hexanes)