Acetic Anhydride → 5,8-Dihydro-2-(4-formyl-1-piperazinyl)-5-oxopyrido[2,3-d]pyrimidine-6-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

Formic acid (140 ml) was added dropwise to acetic anhydride (200 ml) cooled on an ice bath. The solution was heated at 50° C. for 15 minutes and then cooled to 5° C. To the solution, 5,8-dihydro-2-(1-piperazinyl)-5-oxopyrido[2,3-d] pyrimidine-6-carboxylic acid (70 g) was added. The mixture was heated at 80° C. for 3 hours and then cooled. The crystals precipitated were collected by filtration and washed with ethyl ether to give 5,8-dihydro-2-(4-formyl-1-piperazinyl)-5-oxopyrido[2,3-d]pyrimidine-6-carboxylic acid (72.5 g). m.p. above 300° C.

Provenance & Evidence