反应详情

A mixture of 4.85 g of 4-(3-butenyloxy)benzoic acid and 6 ml of thionyl chloride was treated with 3 drops of dimethylformamide and heated to reflux for 3 hrs. The excess acid chloride was thereupon distilled off firstly at normal pressure and then with increasing vacuum, the residue was held under a high vacuum for 2.5 hrs. and subsequently dissolved in 20 ml of methylene chloride. This solution was added dropwise while cooling with ice to obtain a mixture of 5 g of methyl (E)-4-hydroxy-3-methoxycinnamate, 25 ml of methylene chloride and 3.9 ml of triethylamine and subsequently left to react at room temperature for 60 hrs. Then, the reaction solution was filtered, concentrated slightly and chromatographed over 314 g of silica gel with methylene chloride. Crystallization from cold ethanol gave 7.03 g of 2-methoxy-4-[(E)2-methoxycarbonyl-vinyl]phenyl 4-(3-butenyloxy)benzoate.

1. temperatureheated
2. temperatureto reflux for 3 hrs
3. distillationThe excess acid chloride was thereupon distilled off firstly at normal pressure
4. temperaturewith increasing vacuum
5. dissolutionand subsequently dissolved in 20 ml of methylene chloride
6. additionThis solution was added dropwise
7. temperaturewhile cooling with ice
8. customto obtain
9. waitsubsequently left
10. customto react at room temperature for 60 hrs
11. filtrationThen, the reaction solution was filtered
12. concentrationconcentrated slightly
13. customchromatographed over 314 g of silica gel with methylene chloride
14. customCrystallization from cold ethanol