1,3-Dichloroacetone → 7-chloro-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 yellow suspension of 2.45 g (0.00754 mol) of 7-chloro-8-fluoro-5-methyl-6-oxo-5,6-dihydro-4H-imidazo[1,5-a][1,4]benzodiazepine-3-thiocarboxamide in 130 ml of dioxan was treated with 1.05 g (0.00829 mol) of 1,3-dichloro-2-propanone. The suspension was boiled at reflux for 20 hrs. and cooled. A further 1.05 g (0.00829 mol) of 1,3-dichloro-2-propanone and 60 ml of dioxan were added and the solution was boiled at reflux for a further 16 hrs. The solution was cooled and completely freed from the solvents. The residue was chromatographed over silica gel with cyclohexane/ethyl acetate 1:2 as the eluent and recrystallized from hot acetonitrile. There were obtained 1.05 g (35%) of 7-chloro-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. 234-235°.

Provenance & Evidence