反应详情

温度

85 °C

A mixture of 2-methyl-4-o-tolyl-thiazole-5-carboxylic acid (300 mg, 1.29 mmol, 1.0 equiv), diphenyl phosphorylazide (DPPA) (354 mg, 1.29 mmol, 1.0 equiv), and triethylamine (130 mg, 1.29 mmol, 1.0 equiv) in tert-butanol (10 mL) was heated to 85° C. for 4 hours. After cooling, the mixture was diluted with water and extracted with ethyl acetate (3×). The combined organic extracts were dried over magnesium sulphate, filtered, and concentrated under vacuum. The residue was purified by flash column chromatography on silica gel (gradient: 2 to 25% ethyl acetate in pentane) to give 352 mg (90%) of (2-methyl-4-o-tolyl-thiazol-5-yl)-carbamic acid tert-butyl ester as an oil. LCMS (ESI) m+H=305.1; 1H NMR (400 MHz, CDCl3) δ: 7.33-7.24 (m, 4H), 6.58 (s, 1H), 2.64 (s, 3H), 2.24 (s, 3H), 1.48 (s, 9H).

1. temperatureAfter cooling
2. extractionextracted with ethyl acetate (3×)
3. dry with materialThe combined organic extracts were dried over magnesium sulphate
4. filtrationfiltered
5. concentrationconcentrated under vacuum
6. customThe residue was purified by flash column chromatography on silica gel (gradient: 2 to 25% ethyl acetate in pentane)