反应详情

A stirred suspension containing [[4-(ethoxycarbonyl)phenyl]methyl]triphenylphosphonium bromide (11.8 g, 0.0234 mol) in dry tetrahydrofuran (25 ml) at 0° C. under a nitrogen atmosphere was treated with potassium t-butoxide (2.58 g, 0.023 mol). The mixture was allowed to warm up to room temperature and stirred for an additional 90 minutes. The resulting orange mixture was treated with a solution of 1-(1H-imidazol-1-yl)-3-[(4-methoxyphenyl)methoxy]-2-propanone (7.1 g, 0.0273 mol) in dry tetrahydrofuran (25 ml) and stirred for 2 hours. The solvent was evaporated off under reduced pressure and the residue was dissolved in ethyl acetate (300 ml) washed with water (3×150 ml) and extracted into hydrochloric acid (3×200 ml of 5M). The acid solution was basified (K2CO3) and extracted with ethyl acetate (3×250 ml). The extracts were combined, dried over sodium sulfate and the solvent was evaporated off under reduced pressure to yield a crude product. The crude product was purified by column chromatography (silica gel 10% hexane in chloroform). The less polar isomer, ethyl 4-[3-(1H-imidazol-1-yl)-2-[[(4-methoxyphenyl)methoxy]methyl]-1E-propenyl]benzoate was obtained as a colourless oil having the following structural characteristics:

1. stirringstirred for 2 hours
2. customThe solvent was evaporated off under reduced pressure
3. dissolutionthe residue was dissolved in ethyl acetate (300 ml)
4. washwashed with water (3×150 ml)
5. extractionextracted into hydrochloric acid (3×200 ml of 5M)
6. extractionextracted with ethyl acetate (3×250 ml)
7. dry with materialdried over sodium sulfate
8. customthe solvent was evaporated off under reduced pressure
9. customto yield a crude product
10. customThe crude product was purified by column chromatography (silica gel 10% hexane in chloroform)