反应详情

To a solution of {[2-(acetylamino)-1,3-thiazol-4-yl]methyl}(triphenyl)phosphonium chloride (3.771 g, 8.325 mmol) in anhydrous N,N-dimethylformamide (35 ml) was added potassium tert-butoxide (2.515 g, 22.41 mmol) at 0° C., and the mixture was stirred for 15 min. 5-Formylthiophene-2-carboxylic acid (1.000 g, 6.404 mmol) was added by small portions, and the mixture was stirred at 0° C. for 30 min. The mixture was warmed to room temperature, stirred for 2 hr, and poured into iced water (300 ml). After stirring for 30 min, the mixture was washed twice with ethyl acetate. The aqueous layer was cooled to 0° C., and adjusted to pH 3 by dropwise addition of 6M hydrochloric acid. After stirring at 0-5° C. for 2 hr, the precipitated crystals were collected by filtration, washed 3 times with water, and twice with diisopropyl ether and dried under reduced pressure to give 5-{2-[2-(acetylamino)-1,3-thiazol-4-yl]vinyl}thiophene-2-carboxylic acid (1.104 g, 3.751 mmol, yield 58.6%) as a yellow ocher solid.

1. stirringthe mixture was stirred at 0° C. for 30 min
2. stirringstirred for 2 hr
3. stirringAfter stirring for 30 min
4. washthe mixture was washed twice with ethyl acetate
5. temperatureThe aqueous layer was cooled to 0° C.
6. additionadjusted to pH 3 by dropwise addition of 6M hydrochloric acid
7. stirringAfter stirring at 0-5° C. for 2 hr
8. filtrationthe precipitated crystals were collected by filtration
9. washwashed 3 times with water
10. dry with materialtwice with diisopropyl ether and dried under reduced pressure