4-Toluenesulfonyl chloride → HCID 13388351, compound

Participants

Reaction Conditions

Reaction Steps

Stirring a solution of diethyl 2-methyl-4-(2-chlorophenyl)-6-hydroxymethyl-1,4-dihydropyridine-3,5-dicarboxylate (1.1395 g) in dried pyridine (10 ml) at room temperature, a solution of p-toluenesulfonyl chloride (629.1 mg) in dried pyridine (10 ml) was dropwise added gradually thereto. The resultant mixture was stirred at room temperature for 1.5 hours and then heated at 80° C. for 4.5 hours with stirring. After removal of the pyridine, water was added to the residue and the resultant aqueous mixture was acidified with dil. hydrochloric acid and extracted twice with ethyl acetate. The extract was washed with dil. hydrochloric acid and then water, and dried. The resultant brown viscous oil was purified by column chromatography on silica-gel using an eluent (benzene: diethyl ether=1:1) to give an orange oil, which was crystallized by treating with diethyl ether. The resultant crystals were collected by filtration and recrystallized from a mixture of diethyl ether and n-hexane to give orange-yellowish prisms (0.1926 g) of diethyl 2-methyl-4-(2-chlorophenyl)-6-formyl-1,4-dihydropyridine-3,5-dicarboxylate, m.p. 87° to 88° C., which was identified with an authentic sample.

Provenance & Evidence