反应详情

温度

140 °C

A mixture of 2-hydroxy-4-(4-pyridyl)thiazole (17.8 g, 0.10 mol) in phosphorous oxychloride (175 mL) was heated at 140° C. for 48 hours then quenched by carefully pouring onto ice (4000 mL). The resulting mixture was basified with 50% sodium hydroxide to pH 9 and extracted with methylene chloride (5×400 mL). The combined extracts were dried over sodium sulfate, concentrated, and chromatographed over silica gel (ethyl acetate as eluant). Recrystallization from ethyl acetate/hexane afforded 2-chloro-4-(4-pyridyl)thiazole (5.70 g, 29%). mp. 124°-125° C.

1. customthen quenched
2. additionby carefully pouring onto ice (4000 mL)
3. extractionextracted with methylene chloride (5×400 mL)
4. dry with materialThe combined extracts were dried over sodium sulfate
5. concentrationconcentrated
6. customchromatographed over silica gel (ethyl acetate as eluant)
7. customRecrystallization from ethyl acetate/hexane