Methanol → 6-Butyl-4-methoxycarbonyl-2-oxo-1,2-dihydropyridine

Participants

Reaction Steps

12.5 ml (0.17 mol) of thionyl chloride are added dropwise to a suspension of 29.25 g (0.15 mol) of 6-butyl-2-oxo-1,2-dihydro-isonicotinic acid in 200 ml of methanol, while cooling with ice, and the mixture is stirred overnight at room temperature. It is concentrated to dryness and the residue is chromatographed over 450 g of silica gel (230-400 mesh) using methylene chloride→methylene chloride/methanol 10:1. Colourless crystals of melting point 106° C. crystallise from methylene chloride, ether and petroleum ether.

Provenance & Evidence