Sulfuric Acid → HCID 21873921, compound

Participants

Reaction Steps

A cooled solution of 80.4 g of 7-acetyl-2,3-dimethyl-8-pivaloylaminoimidazo[1,2-a]pyridine in 720 ml of methanol is treated with 496 ml of concentated sulfuric acid and heated at reflux for 2.5 hours. It is then poured onto 1 l of ice water, 400 ml of methylene chloride are added and the mixture is adjusted to pH 7 with 10 N sodium hydroxide solution with cooling. After phase separation, the aqueous phase is again extracted twice with 300 ml of methylene chloride each time, the organic phases are collectively washed with 1 l of water, dried over sodium sulfate and the solvent is stripped off in vacuo. The solid residue is purified on silica gel (eluent: ethyl acetate). 22.5 g of the title compound of m.p. 195–97° C. (diethyl ether) are obtained.

Provenance & Evidence