METHOD FOR THE PREPARATION OF CYCLOPROPANE ESTERS

摘要

The method for the preparation of lower alkyl ester of3-(2-chloro-3,3,3-trifluoroprop-1-ene-1-yl)-2,2-dimethylcyclopropane acid includes reaction of a compound having the formulaCF3-CXCl-CH(OH)-CH=C(CH3)2, where X is chloro or bromo, withthree-lower alkyl orthoacetate containing up to 4 carbon atoms ineach alkyl group in the presence of catalytic quantity of acidiccatalyst and at elevated temperaturres until a compound with thefollowing formula is producedCF3-CXCl-CH=CH-C(CH3)2-CH2CO2R IIIwhere R is alkyl group containing up to 4 carbon atoms. Thecompound with formula (III) is treated by at least 1 moleequivalent base until alkyl ester of3-(2-chloro-3,3,3-trifluoroprop-1-ene-1-yl)-2,2-dimethylcyclopropane acid is produced. The products are useful as intermediateproducts in the manufacture of insecticides.11 claims