Carbon Tetrachloride → Ethyl 3-[2-chloro-2-(4-chlorophenyl)ethenyl]-2,2-dimethylcyclopropanecarboxylate

Participants

Reaction Conditions

Reaction Steps

26.3 g (0.1 mol) of 4-chlorobenzyl-phosphonic acid diethyl ester were dissolved in 400 ml of absolute tetrahydrofuran and the solution was cooled to -70° C. 0.11 mol of n-butyl-lithium (15% strength solution in hexane) were added dropwise, in counter-current with nitrogen and while stirring thoroughly, and the reaction mixture was then subsequently stirred at -70° C. for a further 15 minutes. 15.4 g (0.1 mol) of carbon tetrachloride were then added dropwise at -70° C., also under nitrogen, and the reaction mixture thereby became red-brown in color. After stirring for a further 15 minutes, 18.6 g (0.1 mol) of 2,2-dimethyl-3-formyl-cyclopropanecarboxylic acid ethyl ester were added at -65° C. The reaction mixture was then allowed to come to room temperature and was subsequently stirred at 25° C. for a further 3 hours. The reaction mixture was then poured into 2 liters of water and extracted with 600 ml of ether. The ether phase was dried over sodium sulphate, the solvent was stripped off in vacuo and the oily residue was distilled at 150°-155° C./2 mm Hg. 2,2-Dimethyl-3-(2-chloro-2-p-chlorophenyl-vinyl)-cyclopropanecarboxylic acid ethyl ester was obtained in 54.3% yield.

Provenance & Evidence