摘要 |
<p>Compounds of the general formula <IMAGE> in which R<1> and R<2> in each case stand for an alkyl group having 1 to 4 carbon atoms or together form an alkylene group having up to 5 carbon atoms, X<1> and X<2> in each case stand for a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or for a halogen atom or, with one another, form an alkylene group having up to 5 carbon atoms or X<1> denotes a hydrogen atom and X<2> is a monohalovinyl, dihalovinyl or dimethylvinyl group and R stands for a methyl or ethyl group, are prepared. A procedure is used in which a cyclopropanenitrile of the general formula <IMAGE> is reacted with methanol or ethanol under substantially anhydrous conditions at a temperature from 80 to 200 DEG C and in the presence of a mineral acid as a reaction catalyst and of a scavenging agent for the ammonia formed during the reaction. The compounds of the formula I are intermediates for the preparation of synthetic pyrethroids.</p> |