Acetic Anhydride → HCID 13469470, compound

Participants

Reaction Steps

A mixture of diethyl 2-methyl-4-(2-furyl)-6-formyl-1,4-dihydropyridine-3,5-dicarboxylate (1.6 g), hydroxylamine hydrochloride (383.6 mg) and sodium acetate (787.6 mg) in acetic acid (14 ml) was stirred for 30 minutes at room temperature. To the mixture, acetic anhydride (1 ml) was added and stirred for 1.5 hours at room temperature and further stirred for an hour under reflux. After removal of the acetic acid from the reaction mixture, water was added to the residue and the mixture was extracted with ethyl acetate. The extract was washed with saturated sodium bicarbonate solution and water and dried, and then the solvent was distilled off under reduced pressure. The resultant brown oil (1.8 g) was purified by column chromatography on silica gel by an eluent (a mixture of 15 parts of chloroform and one part of ethyl acetate by volume). The concentrate (920 mg) of the fraction of the eluate which showed one spot on thin-layer chromatography and the concentrate of one (450 mg) which showed plural spots respectively gave crystals (totally 875 mg) and these were recrystallized from a mixture of diethyl ether and n-hexane to give pure crystals (818 mg) of diethyl 2-methyl-4-(2-furyl)-6-cyano-1,4-dihydropyridine-3,5-dicarboxylate, m.p. 139° to 141° C.

Provenance & Evidence