反应详情

Into a solution of 200 g (0.58 mol) of methoxymethyltriphenylphosphonium chloride in 1.5 liter of tetrahydrofuran, was added dropwise 220 ml of a tetrahydrofuran solution (2.01 mol concentration) containing 0.44 mol of lithium diisopropylamide under stirring and cooling with ice. After one-hour stirring at room temperature, 400 ml of a tetrahydrofuran solution of 57.6 g (0.38 mol) of methyl 4-formylpyrrole-2-carboxylate was added to the mixture at 5° to 8° C. under cooling with ice. The reaction was carried out for one hour at room temperature, and the reaction mixture was added with water and extracted with ethyl acetate. The organic layer was collected, washed with a saturated solution of sodium chloride, dried over anhydrous magnesium sulfate and evaporated to obtain a residue. The residue was purified by a silica-gel column chromatography (eluent:ethyl acetate/hexane=1/4) to obtain 34.4 g of methyl 4-methoxyvinylpyrrole-2-carboxylate as a mixture of E-isomer and Z-isomer. The yield was 50%.

1. temperaturecooling with ice
2. stirringAfter one-hour stirring at room temperature
3. temperatureunder cooling with ice
4. extractionextracted with ethyl acetate
5. customThe organic layer was collected
6. washwashed with a saturated solution of sodium chloride
7. dry with materialdried over anhydrous magnesium sulfate
8. customevaporated
9. customto obtain a residue
10. customThe residue was purified by a silica-gel column chromatography (eluent:ethyl acetate/hexane=1/4)