(+)2-Ethylthiomethyl-3-carboethoxy-5-carbomethoxy-4-(3-chlorophenyl)-6-methyl-1,4-dihydropyridine → (+)-2,6-Dimethyl-4-(3-chlorophenyl)-3-carboethoxy-5-carbomethoxy-1,4-dihydropyridine

Participants

Reaction Steps

Under nitrogen atmosphere and stirring, a MeOH solution (15 ml) of g 0.85 of (+)2-ethylthiomethyl-3-carboethoxy-5-carbomethoxy-4-(3-chlorophenyl)-6-methyl-1,4-dihydropyridine, cooled at 30° C. is treated with NaH2PO4 (g 1.45) and with Na/Hg amalgam (2.64 g) (10% in Na). After 15 minutes the solution is filtered and evaporated to a small volume under vacuum. The residue is partitioned between water (ml 20) and AcOEt (3×30 ml), the organic phases are collected to give after the usual work-up 0.56 g of (+)-2,6-dimethyl-4-(3-chlorophenyl)-3-carboethoxy-5-carbomethoxy-1,4-dihydropyridine [α]D =+5.5°; c=4.1 CH2Cl2.

Provenance & Evidence