Diphenyl Ether → 3-cyclopropyl-5-hydroxy-8-methyl-1-(3-nitrophenyl)-1H,8H-pyrido[2,3-d]pyrimidine-2,4,7-trione

Participants

Reaction Conditions

Reaction Steps

To 3-cyclopropyl-6-methylamino-1-(3-nitrophenyl)-1H-pyrimidine-2,4-dione 8 (16 g) obtained in Step 4 were added diphenyl ether (160 ml) and diethyl malonate 9 (40 ml), and the mixture was stirred under heating at 230° C. for 11 hrs while evaporating the resulting ethanol. The reaction mixture was purified by column chromatography (chloroform→chloroform:acetone=9:1) to give 3-cyclopropyl-5-hydroxy-8-methyl-1-(3-nitrophenyl)-1H,8H-pyrido[2,3-d]pyrimidine-2,4,7-trione 10 (10 g, 51%) as a brown foamy oil.

Provenance & Evidence