Ethyl Acetate → 2-Methyl-5-(2-nitro-phenylamino)-thiazole-4-carboxylic acid ethyl ester

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Reaction Steps

Add a solution of ethyl 5-amino-2-methylthiazole-4-carboxylate (120 g; 645 mmol) and 2-fluoronitrobenzene (68 mL; 645 mmol) in dimethylsulphoxide (1L) to a 2L 3-necked RB flask equipped with reflux condenser, thermometer, mechanical stirrer. Add lithium hydroxide monohydrate (54 g; 1290 mmol) to the solution and heat at 50° C. for 3 hours under nitrogen. Cool the purple solution and pour onto ice/water, allow to stir for one hour, filter and wash with water, dry at 50° C. under reduced pressure to give 190 g (96%) as an orange solid: mass spectrum (m/e): 308(M+1); 1HNMR(300 MHz, DMSO-d6, ppm): δ 1.25(tr, 3H), 2.56(s, 3H), 4.25(q, 2H), 7.20(m, 1H), 7.78(m, 2H), 8.20(d, 1H), 11.42(s, 1H, NH). 13CNMR(75 MHz, DMSO, ppm): δ 24.4, 29.2, 71.2, 127.8, 132.5, 132.8, 137.8, 146.5, 147.0, 147.5, 160.2, 161.5, 173.7. Formula: C13H13N3O4S.

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