Citric Acid → N-(1-methyl-1-phenylethyl)thiazole-2-carboxamide

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Reaction Steps

7.13 ml (50.0 mmol) of cumylamine and 156 ml of toluene are placed in a 1-liter three-necked flask with stirring and under an inert atmosphere. 24.8 ml (49.6 mmol) of trimethylaluminium are then added dropwise, and white fumes are evolved. After waiting until the medium has clarified, a solution of 3.9 g (24.8 mmol) of ethyl 2-thiazolecarboxylate (2) in 195 ml of toluene is added. The mixture is stirred for 15 minutes and then refluxed. After heating for 15 hours, the reaction medium is poured into 300 ml of 1M citric acid solution diluted with 200 ml of water and the whole is filtered through Celite®. The Celite® is washed with 100 ml of ethyl acetate and the aqueous phase is extracted with twice 100 ml of ethyl acetate. The organic extracts are combined and dried over magnesium sulfate, and after evaporating under reduced pressure, the residue is purified by flash chromatography (msilica=200 g; eluent: dichloromethane). 4.1 g of N-(1-methyl-1-phenylethyl)thiazole-2-carboxamide are obtained in the form of a brick-red solid. Rf(dichloromethane)=0.4.

Provenance & Evidence