Acetic Acid → 5-[4-[2-(4-oxo-3,4-dihydro-2H-1,3-benzoxazin-3-yl)ethoxy]benzylidene]-2,4-thiazolidinedione

Participants

Reaction Steps

5.0 g (17 mM) of 4-[2-(4-oxo-3,4-dihydro-2H-1,3-benzoxazin-3-yl)ethoxy]benzaldehyde (Compound 4A) and 2.1 (18 mM) of 2,4-thiazolidinedione were dissolved in 150 ml of toluene. After the addition of a catalytic amount of acetic acid and piperidine, the mixture was reacted for two hours with heating while refluxing in a Dean Stark apparatus. After confirming completion of the reaction by TLC, the reaction mixture was gradually returned to room temperature. The resulting crystals were collected by filtration and washed with a small amount of toluene and then with hexane, and dried under vacuum at 50° C, to obtain 5.8 g (yield 87%) of the title compound as pale yellow crystals.

Provenance & Evidence