Pyridine → HCID 13785764, compound

Participants

Reaction Steps

A solution of 2,5-dihydro-4-methyl-2-(3-nitrophenyl)-1H-1,5-benzodiazepine-3-carboxylic acid, methyl ester (800 mg., 2.36 mmole) in dichloromethane (8 ml.) is treated with pyridine (280 mg., 3.53 mmole), acetic anhydride (479 mg., 4.72 mmole) and 4-dimethylaminopyridine (5 mg.). The reaction is stirred at room temperature for 16 hours. A light yellow solid precipitates out of the reaction. The reaction is diluted with dichloromethane/methanol (100 ml. of 95:5 mixture) and the resulting solution is washed with 10% citric acid, 5% sodium bicarbonate, and brine. After drying over anhydrous magnesium sulfate, the solvent is evaporated to give a yellow foam. This foam is triturated with ether to give 705 mg. of yellow crystals. Recrystallization from dichloromethane-methanol-isopropanol gives an analytically pure sample of 1-acetyl-2,5-dihydro-4-methyl-2-(3-nitrophenyl)-1H-1,5-benzodiazepine-3-carboxylic acid, methyl ester as yellow crystals; m.p. 231°-232.5°. TLC(silica gel; acetone:hexane, 40:60) Rf = 0.28.

Provenance & Evidence