3,4-dihydro-1H-quinoxalin-2-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The procedure described in Example 4, Steps E through G, was utilized to prepare ethyl-2-oxo-2,3,9,10-tetrahydro-1H-pyrido[3′,4′:4,5]-pyrrolo[1,2,3-de]quinoxaline-8(7H)-carboxylate from the corresponding amine, 1,3,4-trihydroquinoxalin-2-one, and ethyl 4-oxopiperidinecarboxylate. This indole (5.74 g, 19.2 mmol) was dissolved in TFA (100 mL). The reaction was cooled to 0° C. NaCNBH3 (3.96 g, 63.0 mmol) was added in small portions over 30 min, keeping the temperature less than 5° C. The reaction was stirred at r.t. for 4 hr. Ice was added to the reaction flask, and the reaction was basified with 50% NaOH until pH=12. Water (80 mL) was added to dissolve the precipitate. The reaction was extracted with CHCl3 (3×200 mL). The combined organic layers were washed with brine, dried, and concentrated to afford ethyl (6bR,10aS)-2-oxo-2,3,6b,9,10,10a-hexahydro-1H-pyrido[3′,4′:4,5]pyrrolo[1,2,3-de]quinoxaline-8(7H)-carboxylate (4.41 g, 77%). 1H NMR (CDCl3, 300 MHz) δ 8.45 (bs, 1H), 6.86 (d, J=7.4 Hz, 1H), 6.74 (dd, J=7.7 Hz, 7.7 Hz, 1H), 6.63 (d, J=7.3 Hz, 1H), 4.15 (q, J=7.0 Hz, 2H), 3.89–3.993 (m, 2H), 3.41–3.47 (m, 2H), 3.33–3.41 (m, 2H), 3.12–3.31 (m, 1H), 2.69–2.75 (m, 2H), 1.90–1.92 (m, 2H), 1.28 (t, J=7.3 Hz, 3H) ppm. MS-APcI: 302 [MH]+ the temperature less than 5° C Ice was added to the reaction flask to dissolve the precipitate The reaction was extracted with CHCl3 (3×200 mL) The combined organic layers were washed with brine dried concentrated

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: WSC.HCl (640 mg, 3.4 mmol) and 4-(dimethylamino)pyridine (330 mg, 2.7 mmol) were added to a solution of tert-butyl N-(3-carboxybenzyl)-N-methylcarbamate (700 mg, 2.6 mmol) and 1,2,3,4-tetrahydroquinoxalin-2-one (440 mg, 2.9 mmol) in dichloromethane (20 ml). The mixture was stirred for 18 h, reduced in vacuo and taken up in ethyl acetate. This solution was washed with 0.3N potassium hydrogen sulphate and saturated sodium hydrogen carbonate solutions, dried and reduced. Chromatography (50% EtOAc/50% 60-80 pet.ether) afforded tert-butyl N-(3-(1,2,3,4-tetrahydroquinoxalin-3-on-1-carbonyl) benzyl)-N-methylcarbamate (280 mg, 27%) as an orange oil. This solution was washed with 0.3N potassium hydrogen sulphate and saturated sodium hydrogen carbonate solutions dried

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

Procedure: A solution of N-(2-nitrophenyl)glycine methyl ester (740 mg, 3.6 mmol) in ethyl acetate (50 ml) and methanol (25 ml) was hydrogenated at atmospheric pressure over a catalytic amount of 10% palladium on carbon. After 1 h the mixture was filtered and reduced to afford 1,2,3,4-tetrahydroquinoxalin-2-one as a yellow solid (530 mg, 99%). After 1 h the mixture was filtered

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

Procedure: A solution of N-(2-nitrophenyl)glycine methyl ester (740 mg, 3.6 mmol) in ethyl acetate (50 ml) and methanol (25 ml) was hydrogenated at atmospheric pressure over a catalytic amount of 10% palladium on carbon. After 1 h the mixture was filtered and reduced to afford 1,2,3,4-tetrahydroquinoxalin-2-one as a yellow solid (530 mg, 99%). After 1 h the mixture was filtered

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3,4-Dihydro-1H-quinoxalin-2-one (500 mg, 3.378 mmol) was dissolved in 3N HCl (10 mL) and stirred for 5 min. at 0° C. A solution of sodium nitrite (256 mg, 3.716 mmol) in water (2 mL) was added at 0° C., and the reaction mixture was stirred for 2 h at RT. After completion of reaction, water was added and the mixture extracted twice with DCM (100 mL). The combined organic layers were washed with water, dried over sodium sulfate and concentrated under reduced pressure to obtain 400 mg of 3,4-dihydro-4-nitrosoquinoxalin-2(1H)-one. the reaction mixture was stirred for 2 h at RT was added the mixture extracted twice with DCM (100 mL) The combined organic layers were washed with water dried over sodium sulfate concentrated under reduced pressure