Dimethyl Sulfoxide → 2,4-Bis(4-methyl-1-piperazinyl)-3H-1,5-benzodiazepine

Participants

Reaction Conditions

Reaction Steps

3H-[1,5]Benzodiazepine-2,4-diamine (32.50 g, 160 mmol, 86%) was added to a solution of dimethyl sulfoxide (220 ml), toluene (220 ml) and 1-methylpiperazine (165 ml). The mixture was heated for 16 h at 120° C. After cooling the product precipitated. It was filtered off and washed with isopropyl ether (80 ml) to give 40.1 g (74%) of the title compound as off-white needles. The second crop was obtained by adding isopropyl ether (410 ml) to the filtrate. The mixture was allowed to stand overnight at 4° C., the crystallised product was filtered off to give additional 4.25 g (8%) of the title compound. For analytical purposes the product was recrystallised from ethyl acetate.

Provenance & Evidence