反应详情

5N HCl (10 ml) is added to a solution of 4-chloro-5-([1,3]dioxolan-2-yl)-2-methoxy-thiazole (1.80 g, 8.13 mmol) in tetrahydrofuran (50 ml). After 1 h, the reaction is poured into 2N NaOH (100 ml) and extracted with ethyl acetate (3×100 ml). The ethyl acetate is washed with aqueous saturated brine solution, dried with anhydrous Na2SO4, filtered, and concentrated. The crude product is purified by flash chromatography on silica gel eluting with 20% ethyl acetate/hexanes to yield (1.30 g, 90%) of 4-chloro-2-methoxy-thiazole-5-carboxaldehyde: mass spectrum (ion spray): m/z=178.0 (M+1); 1H NMR (CDCl3): δ=9.95 (1H, s), 4.22 (3H, s).

1. extractionextracted with ethyl acetate (3×100 ml)
2. washThe ethyl acetate is washed with aqueous saturated brine solution
3. dry with materialdried with anhydrous Na2SO4
4. filtrationfiltered
5. concentrationconcentrated
6. customThe crude product is purified by flash chromatography on silica gel eluting with 20% ethyl acetate/hexanes