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温度

0 °C

45.6 g (0.2 mol) of benzylphosphonic acid diethyl ester, dissolved in 50 ml of tetrahydrofuran, were added dropwise to a mixture of 300 ml of tetrahydrofuran and 46.4 g (0.22 mol) of a methanolic sodium methylate solution at 0°-5° C., whilst stirring. The mixture was subsequently stirred at 0° C. for 2 hours and 35.6 g (0.2 mol) of 3-formyl-benzoic acid ethyl ester, dissolved in 50 ml of tetrahydrofuran, were then added dropwise, also at 0° C. and whilst stirring. The reaction mixture was then stirred at 20°-25° C. for 12 hours, 300 ml of toluene were subsequently added and the mixture was then extracted by shaking twice with 600 ml of water each time. The organic phase was separated off and dried over magnesium sulphate and the solvent was distilled off under a waterpump vacuum. The oily residue was distilled at 160°-190° C. and under a pressure of 3 mm Hg. The semi-crystalline product thus obtained was dissolved in a little petroleum ether and the solution was cooled to 0° C. The crystals which had precipitated were filtered off and dried. 19 g (37.7% of theory) of 3-(2-phenyl-vinyl)-benzoic acid ethyl ester were obtained as colourless crystals with the melting point 82° C. (isomer mixture, about 90% transconfiguration). ##STR65##

1. stirringThe mixture was subsequently stirred at 0° C. for 2 hours
2. additionwere then added dropwise, also at 0° C.
3. stirringwhilst stirring
4. stirringThe reaction mixture was then stirred at 20°-25° C. for 12 hours
5. extractionthe mixture was then extracted
6. stirringby shaking twice with 600 ml of water each time
7. customThe organic phase was separated off
8. dry with materialdried over magnesium sulphate
9. distillationthe solvent was distilled off under a waterpump vacuum
10. distillationThe oily residue was distilled at 160°-190° C. and under a pressure of 3 mm Hg
11. customThe semi-crystalline product thus obtained
12. customThe crystals which had precipitated
13. filtrationwere filtered off
14. customdried