Uses
Ethyl 2-(2-Formamidothiazol-4-yl)-2-oxoacetate is an intermediate formed in the synthesis of Cefixime Ethyl Ester Sodium Salt (C242830), an ester impurity of the third generation cephalosporin antibiotic, Cefixime (C242800).
Synthesis
A mixture of ethylene acetate tetrahydrate (120 g), acetic acid (1000 ml) and acetic anhydride (100 ml) was stirred in an oil bath heated to 130C to 135C for 20 minutes and potassium permanganate (20 g) was added to the mixture over a period of 5 minutes with stirring at 105C to 110C. The mixture was then stirred further at 130C to 135C for 30 minutes. The mixture was cooled to room temperature and ethyl 2-(2-formylaminothiazol-4-yl)acetate (53.5 g) was added to the mixture. The mixture was then stirred by introducing air at a rate of 6000 ml at 38C to 40C for 15 hrs. per minute. After the reaction, the precipitate was collected by filtration. The precipitate was washed sequentially with acetic acid and water and then dried to give ethyl 2-(2-formylaminothiazol-4-yl)glyoxylate (ethylamino thiazole, 41.5 g) with a melting point of 232-233C (decomposition).
