Hydrochloric Acid → HCID 13469471, compound

Participants

Reaction Steps

To a solution of diethyl 2-methyl-4-(2-methoxyphenyl)-6-formyl-1,4-dihydropyridine-3,5-dicarboxylate (1.1320 g) in ethanol (30 ml) was gradually added sodium borohydride (114 mg) under stirring and the resultant mixture was further stirred at room temperature for an hour. The resultant mixture was acidified with dilute hydrochloric acid. After removing ethanol from the mixture, water was added to the residue to solidify. The solid was collected by filtration, dried and washed with diethyl ether. The diethyl ether washings were concentrated to the volume of about 10 ml and stood at room temperature to give pale yellowish granules (372.5 mg) of diethyl 2-methyl-4-(2-methoxyphenyl)-6-hydroxymethyl-1,4-dihydropyridine-3,5-dicarboxylate, m.p. 125° to 126° C. On the other hand, the solid obtained above, which was collected by filtration and washed with diethyl ether, was added to a mixed solution of p-toluenesulfonic acid (catalytic amount) in ethanol (5 ml) and the mixture was refluxed for one hour. After removal of ethanol, the residue was pulverized with diethyl ether and collected by filtration. The powder was recrystallized from a mixture of acetone and ethyl acetate to give colorless granules (114.8 mg) of ethyl 2-methyl-4-(2-methoxyphenyl)-5-oxo-1,4,5,7-tetrahydrofuro[3,4-b]-pyridine-3-carboxylate, m.p. 219° to 220° C.

Provenance & Evidence