Water → HCID 18523425, compound

Participants

Reaction Conditions

Reaction Steps

A stirred suspension of 3 g of ethyl 7,8-difluoro-4-methyl-1-oxo-1,4-dihydrobenzo[f][1,7]naphthyridine-2-carboxylate and 3.9 g of 1-(3-fluoro-4-methylphenyl)piperazine in 30 cm3 of dimethyl sulphoxide was heated at a temperature in the region of 100° C. for about 100 hours. The reaction mixture was treated with 150 cm3 of water in the region of 10° C. and the precipitate was taken up in 100 cm3 of dichloromethane, dried with 10 g of magnesium sulphate and concentrated to dryness under reduced pressure (20 kPa). The yellow powder obtained was chromatographed on a Merck silica gel column (particle size 0.04-0.06 mm, diameter 3 cm, height 80 cm), eluted at an argon pressure of 1 bar with a mixture of dichloromethane and methanol (98/2 mixture by volume), and 200 cm3 fractions were collected. Fractions 16 to 23 were combined and then concentrated to dryness under reduced pressure (2.7 kPa). The yellow solid obtained was washed with 10 cm3 of diethyl ether, filtered and dried. 1.1 g of ethyl 7-fluoro-8-[4-(3-fluoro-4-methylphenyl)piperazin-1-yl]-4-methyl-1-oxo-1,4-dihydrobenzo[f][1,7]naphthyridine-2-carboxylate was obtained in the form of a yellow solid, which melted at a temperature in the region of 290° C.

Provenance & Evidence