HCID 20272886, compound → HCID 13242128, compound

Participants

Reaction Steps

3 g of monomethyl 1,4-dihydro-2,6-dimethyl-4-[2-(4-methylbenzyloxy)-phenyl]-pyridine-3,5-dicarboxylate were suspended in 30 ml of diethylene glycol, and the suspension was heated to 170° to 180° C. while stirring, a clear solution being formed with evolution of gas. The mixture was stirred for approx. 5 minutes at 180° C., and was cooled. The viscous solution was dissolved in an ether/water mixture with vigorous shaking, the mixture was separated, the aqueous phase was extracted with ether, and the combined ether phases were washed with 1N sodium hydroxide solution and twice with water. The ether phase was dried, filtered and concentrated. The resulting syrupy residue was crystallized in an ice-bath, using isopropanol or acetonitrile, and the crystals were filtered off under suction. 1.6 g of methyl 1,4-dihydro-2,6-dimethyl-4-[2-(4-methylbenzyloxy)-phenyl]-pyridine-3-carboxylate of melting point 107° C. to 109° C. were obtained.

Provenance & Evidence