2-methyl-1,2,3,5-tetrahydro-1,5-benzodiazepin-4-one

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A disposable tube was charged with 4-methyl-4,5-dihydro-1H-benzo[b][1,4]diazepin-2(3H)-one (220 mg, 1.248 mmol) in THF (12 mL). Lawesson's Reagent (278 mg, 0.687 mmol) was added, and the solution was stirred at 80° C. 1 h. The solution was concentrated with celite and purified by silica gel chromatography to yield 4-methyl-4,5-dihydro-1H-benzo[b][1,4]diazepine-2(3H)-thione as a yellow foam (0.163 g, 0.848 mmol, 68%). 1 h The solution was concentrated with celite purified by silica gel chromatography

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

Procedure: An round bottomed flask was charged with ethyl 3-(2-aminophenylamino)butanoate (684 mg, 3.08 mmol) and a stirbar. MeOH (15 mL, 0.1 M) was added, followed by sodium methoxide (249 mg, 4.62 mmol), and the solution was stirred at reflux for 48 h. The mixture was concentrated with celite and purified by silica gel chromatography (eluting with hexanes/ethyl acetate) to yield 4-methyl-4,5-dihydro-1H-benzo[b][1,4]diazepin-2(3H)-one as an off-white amorphous solid (0.22 g, 1.25 mmol, 41%). at reflux for 48 h The mixture was concentrated with celite purified by silica gel chromatography (eluting with hexanes/ethyl acetate)

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

Procedure: A solution of 4-methyl-4,5-dihydro-1H-benzo[b][1,4]diazepin-2(3H)-one (220 mg, 1.25 mmol) and P2S5 (444 mg, 2.0 mmol) in pyridine (10 mL) was heated at 120° C. for 30 min. To the mixture, water (10 mL) was added, and then extracted with ethyl acetate (20 mL), dried with Na2SO4, concentrated and purified by CombiFlash (PE:EA=10:1) to give 4-methyl-4,5-dihydro-1H-benzo[b][1,4]diazepine-2(3H)-thione (200 mg, 83%). LRMS (M+H)+: 192 m/z. extracted with ethyl acetate (20 mL) dried with Na2SO4 concentrated purified by CombiFlash (PE:EA=10:1)