[Na].C(OP([CH:10]([Cl:19])[C:11]1[CH:16]=[CH:15][C:14]([O:17][CH3:18])=[CH:13][CH:12]=1)(=O)OCC)C.[CH3:20][C:21]([CH3:25])=[CH:22][CH:23]=O.O>C(O)C.O1CCCC1>[CH3:18][O:17][C:14]1[CH:13]=[CH:12][C:11]([C:10]([Cl:19])=[CH:23][CH:22]=[C:21]([CH3:25])[CH3:20])=[CH:16][CH:15]=14.6 g (0.2 mol) of sodium were dissolved incrementally in 100 ml of dry ethanol. When all the sodium had dissolved, 100 ml of anhydrous tetrahydrofuran were added and 58.4 g (0.2 mol) of 4-methoxy-α-chloro-benzyl-phosphonic acid diethyl ester, dissolved in 50 ml of anhydrous tetrahydrofuran, were added dropwise at 0° C., while stirring. After stirring had been continued at 0°-10° C. for a further 1 hour, 16.8 g (0.2 mol) of β,β-dimethylacrolein, dissolved in 30 ml of anhydrous tetrahydrofuran, were added dropwise, while stirring. Stirring was then continued at room temperature for a further 12 hours. 600 ml of water were then added to the reaction mixture and the mixture was extracted twice with 300 ml of methylene chloride each time. The organic phase was separated off and dried over magnesium sulphate, the solvent was distilled off under a waterpump vacuum and the residue was distilled in vacuo. 25 g of 1-(4'-methoxyphenyl)-1-chloro-4,4-dimethyl-1,3-butadiene (isomer mixture) were obtained as a yellow oil which had a boiling point of 130°-145° C./2 mm Hg and partially crystallized after some time.
Loading…
