反应详情

Sodium methoxide (0.63 g, 11.66 mmol) is added to a solution of 2,4-dichloro-5-([1,3]dioxolan-2-yl)-thiazole (2.00 g, 8.85 mmol) in methanol (20 ml). The reaction is heated at reflux for 3.5 h, cooled, and concentrated. The residue is partitioned between aqueous saturated brine solution and ethyl acetate, separated, and the aqueous layer extracted with ethyl acetate. The ethyl acetate is dried over Na2SO4, filtered, and concentrated. The crude product is purified by flash chromatography on silica gel eluting with 12.5% ethyl acetate/hexanes to yield (1.12 g, 93%) of 4-chloro-5-([1,3]dioxolan-2-yl)-2-methoxy-thiazole: mass spectrum (ion spray): m/z=221.9 (M+1); 1H NMR (CDCl3): δ=6.05 (1H, s), 4.15-3.97 (7H, m).

1. temperatureThe reaction is heated
2. temperatureat reflux for 3.5 h
3. temperaturecooled
4. concentrationconcentrated
5. customThe residue is partitioned between aqueous saturated brine solution and ethyl acetate
6. customseparated
7. extractionthe aqueous layer extracted with ethyl acetate
8. dry with materialThe ethyl acetate is dried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated
11. customThe crude product is purified by flash chromatography on silica gel eluting with 12.5% ethyl acetate/hexanes