Nordiazepam → 7-chloro-2,3-dihydro-2-oxo-5-phenyl-1H-1,4-benzodiazepin-1-acetic acid methyl ester

Participants

Reaction Steps

Sodium methoxide (5.95 g., 0.11 mole) is added to a solution of 7-chloro-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one (27 g., 0.1 mole) in 200 ml. of dimethylformamide and the mixture is stirred and heated on a steambath for about 20 minutes. To this mixture is added a solution of methyl bromoacetate (16.7 g., 0.11 mole) in 165 ml. of toluene during 1 hour while stirring and heating are continued. The mixture is heated for an additional 2 hours, allowed to stand overnight at room temperature (about 25° C.) and evaporated to dryness in vacuo. The residue is stirred with 500 ml. of water until a suspension results. The suspension is filtered and the solid thus obtained is crystallized first from ether and then from ethanol to give 14.5 g. (42% yield) of 7-chloro-2,3-dihydro-2-oxo-5-phenyl-1H-1,4-benzodiazepine-1-acetic acid methyl ester of melting point 137°-138° C.

Provenance & Evidence