Dimethyl Sulfoxide → 3-Cyano-1-cyclopropyl-6,8-difluoro-1,4-dihydro-7-(4-hydroxypiperazin-1-yl)-4-oxoquinoline

Participants

Reaction Conditions

Reaction Steps

1-Hydroxypiperazine dihydrochloride (2.45 g) (which is prepared in Preparation 1), dimethylsulfoxide (20 ml) and triethylamine (5.05 g) are added to 1-cyclopropyl-3-cyano-1,4-dihydro-4-oxo-6,7,8-trifluoroquinoline (2.64 g), which is prepared in Preparation 3, and the mixture is stirred with heating at 100° C. for 4 hours. After cooling to room temperature, water (300 ml) is added to the reaction mixture, and the resulting precipitate is filtered and washed with water to afford 3-cyano-1-cyclopropyl-6,8-difluoro-1,4-dihydro-7-(4-hydroxypiperazin-1-yl)-4-oxoquinoline (2.84 g) as pale yellow powder. The powder is recrystallized from dimethylsulfoxide to yield light brown needles, m.p. about 214° C. (decomposition).

Provenance & Evidence