Thiazolidinedione → HCID 20703757, compound

Participants

Reaction Steps

2,4-Thiazolidinedione (46g) and 4-(2-hydroxyethoxy)-benzaldehyde (65g) were mixed in toluene (400ml) containing acetic acid (1.0 ml) and piperidine (1.0 ml) in an apparatus incorporating a water-trap. The mixture was boiled under reflux with vigorous stirring for 30 minutes, during which time the theoretical quantity of water was obtained and 5-[4-(2-hydroxyethoxy)benzylidene]-2,4-thiazolidinedione started to crystallise. The solution was cooled and the benzylidene compound (mp 194° C.-196° C.) collected by filtration. This product was suspended in methanol (2 l.) and treated portionwise with magnesium turnings (2 g). When the vigorous reaction started a cooling bath was applied and the rest of the magnesium (78 g) was added portionwise with stirring. The mixture was stirred overnight at ambient temperature and the solvent was then evaporated. 5% Hydrochloric acid solution (1000 ml), water (500 ml) and methanol (500 ml) were added. When gas evolution ceased the mixture was extracted with dichloromethane, the organic phase dried (MgSO4), filtered and evaporated under reduced pressure. The title compound was obtained pure by crystallisation from aqueous methanol (m.p. 137°-9° C.).

Provenance & Evidence