Dimethyl Sulfoxide → 6,7-Dichloro-2-methyl-10-(4-methyl-piperazin-1-yl)-2,4-dihydro-1,2,3,4,9-pentaaza-benzo[f]azulene

Participants

Reaction Conditions

Reaction Steps

10-Amino-6,7-dichloro-2-methyl-2,4-dihydro-1,2,3-triazolo[4,5-b][1,5]benzodiazepine hydrochloride (0.84 g) was added to a mixture of dry dimethylsulphoxide (5 ml), toluene (5 m) and N-methylpiperazine (1 ml), which had been purged with nitrogen for 20 minutes. The stirred solution was then heated at 125° C. (oil bath) under nitrogen for 16 hours, cooled to room temperature, and distilled water (10 ml) added, keeping the temperature below 25° C. After stirring at 5° C. for half an hour, the suspension obtained was filtered off and dried at 70° C. under reduced pressure to leave a yellow-brown solid which was recrystallised from ethyl acetate/n-hexane to give a yellow crystalline solid, melting point 217.5°-218.5° C.

Provenance & Evidence