1,3-Dichloroacetone → 3-(4-chloromethyl-thiazol-2-yl)-8-fluoro-5-methyl-5,6-dihydro-4H-imidazo[1,5-a][1,4]benzodiazepin-6-one

Participants

Reaction Steps

A suspension of 4.51 g (0.0155 mol) of 8-fluoro-5-methyl-6-oxo-5,6-dihydro-4H-imidazo[1,5-a][1,4]benzodiazepine-3-thiocarboxamide in 100 ml of dioxan was treated with 2.16 g (0.0171 mol) of 1,3-dichloro-2-propanone. The suspension was boiled at reflux for 41 hrs., cooled and completely freed from the solvents. The residue was chromatographed over silica gel with dichloromethane/ethyl acetate 1:1 as the eluent and recrystallized from hot ethyl acetate. There were obtained 3.23 g (57%) of 3-(4-chloromethyl-thiazol-2-yl)-8-fluoro-5-methyl-5,6-dihydro-4H-imidazo[1,5-a][1,4]benzodiazepin-6-one as white crystals; m.p. 239-241°.

Provenance & Evidence