Phosphoric Acid → Vesnarinone

Participants

Reaction Steps

A mixture of 2.7 g of 6-amino-3,4-dihydrocarbostyril, 5.9 g of N,N-bis(2-hydroxyethyl)-3,4-dimethoxybenzamide and 8.6 g of 85% phosphoric acid was reacted at 165° to 175° C. for 4.5 hours while stirring. After allowing to cool, to the reaction mixture was added dropwise about 50 ml of water to dissolve. The solution was neutralized with an aqueous 48% sodium hydroxide solution and extracted with chloroform. After drying the extract over potassium carbonate, chloroform was distilled off. Recrystallization of the residue from ethanol-chloroform gave 4.7 g of 6-[4-(3,4-dimethoxybenzoyl)-1-piperazinyl]-3,4-dihydrocarbostyril, m.p. 238°-239.5° C., colorless granules.

Provenance & Evidence