1-Methylpiperazine → 3-Cyano-7-fluoro-1-methyl-8-(4-methyl-1-piperazinyl)-4-oxobenzo[b][1,8]naphthyridine

Participants

Reaction Steps

A suspension of 2.1 g of 3-cyano-7,8-difluoro-1-methyl-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine in 100 cm3 of dimethyl sulphoxide is heated to 80° C. in the presence of 2 cm3 of N-methylpiperazine. The reaction mixture is maintained at this temperature for 8 hours. The solution obtained is cooled to room temperature and stirred at this temperature for 15 hours. The precipitate formed is filtered off, washed with 3 times 20 cm3 of water and dried under vacuum (20 kPa) at 50° C. 2.6 g of 3-cyano-7-fluoro-1-methyl-8-(4-methyl-1-piperazinyl)-4-oxobenzo[b][1,8]naphthyridine are obtained in the form of a yellow precipitate, melting point 335° C.

Provenance & Evidence