3-Phenoxybenzyl alcohol → (3-Phenoxy)benzyl 2-vinyl-1-cyanocyclopropane-1-carboxylate

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Utilizing the product prepared in Example I, a transalcoholysis was carried out with 3-phenoxybenzyl alcohol to obtain (3-phenoxy)benzyl 2-vinyl-1-cyanocyclopropane-1-carboxylate. A three-fold molar excess of the ethyl 2-vinyl-1-cyanocyclopropane-1-carboxylate was employed for the reaction. About 0.7 wt. percent calcium acetate, based on the total reactant charge, was used as the catalyst and a small amount of hydroquinone added as an oxidation and polymerization inhibitor. The reaction mixture was heated with agitation to 150° C. and about 4 wt. percent dibutyltin oxide charged. After 5 hours additional heating the reaction was terminated and the resulting product, containing about 35% of the desired (3-phenoxy)benzyl 2-vinyl-1-cyanocyclopropane-1-carboxylate, dissolved in ethyl ether, filtered to remove insoluble catalyst residue, washed with 5% aqueous sodium hydroxide and saturated sodium chloride solutions. After evaporation of the ethyl ether, the product was dissolved in toluene and separated from the unreacted starting materials using a Waters Preparatory Liquid Chromatograph 500A equipped with a gel permeation column and operated at a flow rate of 0.1 l/min. After two passes, 92+% pure (3-phenoxy)benzyl 2-vinyl-1-cyanocyclopropane-1-carboxylate was obtained and the structure of the product confirmed by mass spectroscopy and nuclear magnetic resonance spectroscopy.

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