Hydrochloric Acid → HCID 54703303, compound

Participants

Reaction Steps

Sodium hydride (132 g, 5.52 mol) was added gradually into isopropyl alcohol (2-3 l) with cooling. To the resulting solution was then added a mixture of isopropyl pyruvate (360 g, 2.76 mol) and di-isopropyl 2,2'-thiodiglycolate (648 g, 2.76 mol) over 20-30 minutes with ice-cooling so that the solution was kept at 60°-80° C. The solution was stirred further for 2 hours at a temperature of 60°-40° C. The solution was poured into an ice-cooled dilute hydrochloric acid solution to form a white crystalline mass, which was recovered by filtration and then washed with water. It was recrystallized from methanol (3 l) to give pure di-isopropyl 3-methyl-4-hydroxy-2,5-thiophene-dicarboxylate (270 g, 34%), m.p. 87°-89° C.

Provenance & Evidence