Flumazenil → HCID 20434818, compound

Participants

Reaction Steps

A mixture of 5 g (16.5 mmol) of ethyl 8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate, 1.8 g (8 mmol) of tetraethyl orthotitanate and 16.5 g (230 mmol) of hydroxymethyl-cyclopropane is stirred at 110° overnight, evaporated to dryness, the residue is taken up in methylene chloride and the solution obtained is stirred for 0.5 hour with 50 ml of a saturated potassium fluoride solution. The emulsion obtained is filtered through siliceous earth, the separated organic phase is washed with water, dried over magnesium sulphate and evaporated. By crystallization from ethyl acetate there is obtained cyclopropylmethyl 8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate of melting point 156-157°.

Provenance & Evidence