Water → HCID 14853344, compound

Participants

Reaction Conditions

Reaction Steps

A suspension of 0.93 g of 7,8-difluoro-1-methoxy-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine- 3-carboxylic acid in 0.6 g of 1-methylpiperazine and 20 cm3 of dimethyl sulphoxide is heated at a temperature close to 80° C. for 5 minutes. After cooling to about 20° C., the reaction mixture is poured into 30 cm3 of water, 1.5 cm3 of 2N methanesulphonic acid are added and the product is drained and washed with 3 times 5 cm3 of water. After recrystallizing from 30 cm3 of dimethylformamide containing 30% of ethanol, 0.55 g of 7-fluoro-1-methoxy-8-(4-methyl-1-piperazinyl)-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine-3-carboxylic acid is obtained in the form of a brown solid melting at 270° C.

Provenance & Evidence