反应详情

温度

0 °C

2-(5-Methyl-2-phenyl-4-oxazolyl) acetic acid (0.40 g, 1.8 mmol) dissolved in 5 mL of CH2Cl2 was cooled to 0°-5° C. Triethylamine (0.46 mL) and then ethyl chloroformate (0.30 mL) were each added dropwise. After stirring at 15 minutes at 0° C. to assure complete conversion of the acid to the intermediate mixed anhydride, a solution of 5-(4-aminobenzyl) thiazolidine-2,4-dione (0.71 g, 3.2 mmol; Chem. Pharm. Bull. Japan, v. 30, p. 3580, 1982) and 0.24 mL triethylamine in 15 mL were added dropwise as the temperature was maintained at 0°-5° C. The resulting solution was then stirred for 18 hours at room temperature, stripped of solvent and the residue distributedbetween 25 mL 2N HCl and 25 mL ethyl acetate. The aqueous layer was extracted with 25 mL additional ethyl acetate, and the organic layers combined, washed sequentially 1×30 mL water, 1×30 mL saturatedNaHCO3 and 1×30 mL saturated NaCl, dried (Na2SO4) andstripped to yield 0.84 g of solids. The latter was flash chromatographed onsilica gel using 1:2 ethyl acetate:hexane as eluant to yield 0.23 g of impure title product suitable for rechromatography and 0.20 g of purified title product.

1. temperaturewas cooled to 0°-5° C
2. additioneach added dropwise
3. temperaturewas maintained at 0°-5° C
4. stirringThe resulting solution was then stirred for 18 hours at room temperature
5. extractionThe aqueous layer was extracted with 25 mL additional ethyl acetate
6. washwashed sequentially 1×30 mL water, 1×30 mL saturatedNaHCO3
7. dry with material1×30 mL saturated NaCl, dried (Na2SO4)