preparation | compound thiazole -4-formic acid (15g,116mmol) is dissolved with tert-butanol (750ml), DPPA(47.95g,174mmol) and triethylamine (37.5ml,232mmol) are added, reflux reaction is added at 110 ℃ overnight, and the solvent is dried after the reaction is finished, stir with ethyl acetate (400ml), wash with 5% citric acid solution (200ml), wash with water (200ml), wash with saturated sodium bicarbonate solution (200ml), wash with saturated salt water (200ml), dry with anhydrous sodium sulfate, spin-dry solvent silica gel column chromatography purification (PE/EA = 30:1 → 15:1) to obtain compound N-BOC-4-aminothiazole, white solid 16.2g, yield 69.8%. |