8-chloro-6-(o-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid synthesis

Yield:-

Reaction Conditions:

with potassium hydroxide in methanol;water;

Steps:

82 8-Chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine 3-carboxylic acid

EXAMPLE 82 8-Chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine 3-carboxylic acid A mixture of 7.7 g. (0.02 m) of methyl 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine 3-carboxylate, 2.24 g. (0.04 m) of potassium hydroxide, 200 ml. of methanol and 6 ml. of water was heated to reflux for 31/2 hours. The solvent was partially evaporated and the residue was acidified with glacial acetic acid and diluted with water while hot. The precipitated crystals were collected after cooling in ice/water and were dried to yield the final productproduct. For analysis it was recrystallized from methylene chloride/methanol/ethyl acetate, m.p. 271°-274° dec.

References:

US4280957,1981,A