反应详情

2 ml of 1 N sodium hydroxide was dropwise added under nitrogen atmosphere and under ice-cooling to a solution of 175 mg of 4-(6-carbomethoxyhexyl)-5-(3-keto-1-trans-octenyl)-thiazole (Ia, R1 = H) in 5 ml of ethanol. The solution was subsequently stirred for 1.5 hours at room temperature. Then the reaction mixture was poured onto 30 ml of icewater, acidified with 1 N hydrochloric acid and extracted with 3 × 15 ml of ethyl acetate. The ethyl acetate extract was dried over sodium sulphate and evaporated in vacuo. The evaporation residue was purified by preparative thin layer chromatography, using a silica gel layer as adsorbent and the organic phase of a mixture of 110 ml of ethyl acetate, 50 ml of n-heptane, 100 ml of water and 20 ml of acetic acid as running solvent. In this way 71 mg of 4-(6-carboxyhexyl)-5-(3-keto-1-trans-octenyl)-thiazole (Ib, R1 = H) of chromatographic purity were obtained. The m.p. and spectroscopical data of the product agreed with those specified in Example 5.

1. additionThen the reaction mixture was poured onto 30 ml of icewater
2. extractionextracted with 3 × 15 ml of ethyl acetate
3. extractionThe ethyl acetate extract
4. dry with materialwas dried over sodium sulphate
5. customevaporated in vacuo
6. customThe evaporation residue was purified by preparative thin layer chromatography
7. additionthe organic phase of a mixture of 110 ml of ethyl acetate, 50 ml of n-heptane, 100 ml of water and 20 ml of acetic acid