Preparation of .alpha.-cyanobenzyl esters
AssigneeShell Oil Company
InventorCharles H. Tieman
Life of this patent
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Abstract
New .alpha.-halobenzyl esters, intermediates for .alpha.-cyanobenzyl pyrethroid esters, are prepared by treating a benzaldehyde derivative with a pyrethroid acid halide. The resulting .alpha.-halobenzyl ester is treated with a water-soluble compound capable of generating cyanide ions (CN.sup.-) to give the corresponding .alpha.-cyanobenzyl esters.
Claims15
A process for the preparation of .alpha.-cyanobenzyl esters of the formula X ##STR12## wherein ##STR13## is the residue of a pyrethroid acid in which R is a group of the formula IX ##STR14## wherein R.sub.1 is a member selected from the group consisting of hydrogen, methoxy, ethoxy, acetoxy, methylsulfinyl, difluoromethoxy, trifluoromethoxy, C.sub.1 -C.sub.4 alkyl, trifluoromethyl, allyl, acetyl, ethoxycarbonyl, methylthio, chlorine, fluorine, iodine, isopropenyl, propargyl, methoxymethyl, ethoxymethyl, chloroallyl, butyryl, butylthio, allyloxycarbonyl, nitro and methoxycarbonyl;
- R.sub.2 is a member selected from the group consisting of hydrogen, methyl, methoxy, chlorine and bromine;
- or R.sup.1 and R.sup.2 together are methylenedioxy, trimethylene or tetramethylene;
- R.sub.3 is hydrogen or methyl;
- Z is a member selected from the group consisting of C.sub.1 -C.sub.4 alkyl, ethoxy, allyl, bromoethyl, cyclohexyl, cyclopropylmethyl, isopropenyl, propargyl, trifluoromethyl and cyano, which comprises treating an .alpha.-halobenzyl ester of the formula I ##STR15## wherein ##STR16## has the above meaning and X is a chlorine, fluorine or bromine atom;
- and X.sup.1 is a hydrogen, chlorine, fluorine or bromine atom with a water-soluble compound capable of generating cyanide ions (CN.sup.-) in the presence of an inert solvent.
Dependencies are inferred from the claim text.