A solution of 3.1 g (15.6 mmol) of ethyl 2-isopropylthiazole-4-carboxylate in 50 ml of dichloromethane was cooled under N2 atmosphere to -78° C and treated dropwise with 15.6 ml (23.4 mmol) of a 1.5 M solution of diisobutylaluminum hydride in toluene over 1.5 h. After being stirred for an additional 0.5 h, the solution was quenched with 5 ml of methanol followed by 15 ml of aqueous Rochelle's salt. The resulting mixture was partitioned between chloroform and aqueous Rochelle's salt, dried over Na2SO4, and concentrated to provide 1.37 g (56 %) of the crude 4-Formyl-2-isopropylthiazole.
