反应详情

To a cold (-5° C.) solution of 4.0 g (0.0166 mole) of ethyl 2-amino-4trifluoromethyl-5-thiazolecarboxylate, prepared according to U.S. Pat. No. 2,726,237, in 30 ml. of 85% phosphoric acid and 30 ml. of 70% nitric acid was added a solution of 1.26 g (0.0166 mole) of sodium nitrite in 10 ml. of water in 10 minutes. The reaction mixture was stirred for 10 minutes and poured into a solution of 10 g of potassium iodide in 100 ml. of water. The reaction mixture was stirred overnight and extracted with ether. The ether solution was dried and concentrated and the residue was chromatographed on silica gel to give 1.5 g of the desired product, m.p. 75°-76° C.

1. stirringThe reaction mixture was stirred overnight
2. extractionextracted with ether
3. dry with materialThe ether solution was dried
4. concentrationconcentrated
5. customthe residue was chromatographed on silica gel