反应详情

To a solution of ethyl 2-(hydroxymethyl)-thiazole-4-carboxylate 33 (38.4 g) and pyridine (41 mL) in 100 mL of CH2Cl2 is slowly added 2,2,2-trichloroethyl chloroformate (32 mL, 0.23 mol) at 0° C. After the resulting mixture is stirred for 30 minutes, the reaction is quenched by the addition of 10% aq NaHCO3. The organic layer is separated, and the aqueous layer is extracted with CH2Cl2. The combined organic extracts are washed with 2 N HCl, 10% aq NaHCO3, and brine, dried (Na2SO4), and concentrated. The residue is then recrystallized in ethanol (50 mL) to yield a light yellow solid (35 g). The mother liquor is concentrated and chromatographed to afford an additional amount (35 g) of product.

1. customat 0° C
2. customthe reaction is quenched by the addition of 10% aq NaHCO3
3. customThe organic layer is separated
4. extractionthe aqueous layer is extracted with CH2Cl2
5. washThe combined organic extracts are washed with 2 N HCl, 10% aq NaHCO3, and brine
6. dry with materialdried (Na2SO4)
7. concentrationconcentrated
8. customThe residue is then recrystallized in ethanol (50 mL)