Dichloromethane → 7-chloro-2,3-dihydro-2-oxo-5-phenyl-1H-1,4-benzodiazepine-3-carboxylic acid isopropyl ester

Participants

Reaction Conditions

Reaction Steps

500 Ml. of propanol-(2) are treated with 14 g. of sodium methylate; the methanol formed is removed by concentration in vacuo to half the volume and the suspension obtained is diluted with 250 ml. of methylene chloride. Then, 34.2 g. of 7-chloro-2,3-dihydro-2-oxo-5-phenyl-1H-1,4-benzodiazepine-3-carboxylic acid ethyl ester are added and the mixture is subsequently stirred at 25° C. for 40 minutes. The orange solution is made acidic with glacial acetic acid and evaporated to dryness under reduced pressure. The residue is partitioned between water and chloroform; the organic phase is washed with a saturated aqueous solution of sodium chloride, dried over sodium sulfate and concentrated to dryness. The solid crude product is triturated with ether, removed by filtration, washed with ether and recrystallized from methylene chloride/ether, whereby there is obtained 7-chloro-2,3-dihydro-2-oxo-5-phenyl-1H-1,4-benzodiazepine-3-carboxylic acid isopropyl ester having a melting point of 234°-238° C. (decomposition).

Provenance & Evidence