反应详情

To a solution of sodium trifluoroethoxide, prepared from trifluoroethanol (2 ml) and sodium hydride (37 mg, 0.84 mmol) at 0-5° C., was added dropwise a solution of ethyl 5-bromo-2-(methylsulfonyl)pyrimidine-4-carboxylic acid ethyl ester (200 mg, 0.65 mmol; example 126, step 1) dissolved in trifluoroethanol (2 ml) at the same temperature. The ice bath was removed after 15 min and the mixture was stirred at r.t. for 4 h. The reaction mixture was poured into ethyl acetate (20 ml) and extracted with potassium hydrogen sulfate (10%, 10 ml). The organic phase was washed with water and brine and the aqueous layers were back-extracted with ethyl acetate. The combined organic layers were dried and evaporated and the product was obtained after purification by silica gel chromatography using a heptane/ethyl acetate gradient as colorless oil (186 mg, 87%).

1. customThe ice bath was removed after 15 min
2. additionThe reaction mixture was poured into ethyl acetate (20 ml)
3. extractionextracted with potassium hydrogen sulfate (10%, 10 ml)
4. washThe organic phase was washed with water and brine
5. extractionthe aqueous layers were back-extracted with ethyl acetate
6. customThe combined organic layers were dried
7. customevaporated
8. customthe product was obtained
9. customafter purification by silica gel chromatography