학술논문
Process for the preparation of pyrethroid type ester compounds
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Patent
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Abstract
The present invention relates to a novel process for the preparation of insecticidally active esters of the general formula (I) ##STR1## wherein R.sub.1 and R.sub.2 are the same or diferent from each other and represent a hydrogen or a halogen atom; R.sub.3 represents ##STR2## (wherein R.sub.4 and R.sub.5 represent a chlorine or bromine atom or a methyl group when R.sub.4 is identical to R.sub.5, but R.sub.4 represents a chlorine or bromine atom or a methyl group and R.sub.5 represents a trifluoromethyl group when R.sub.4 is different from R.sub.5, and R.sub.6 represents a halogen atom or a difluoromethoxy group); and R.sub.8 represents a hydrogen or a cyano group.
The characteristic of the present invention is a one-step procedure comprising directly condensing an organic acid, an aldehyde (and a water-soluble cyanide) in the presence of a phase transfer catalyst and a water-soluble inorganic base by the use of a sulphonyl compound as a condensing reagent.
The characteristic of the present invention is a one-step procedure comprising directly condensing an organic acid, an aldehyde (and a water-soluble cyanide) in the presence of a phase transfer catalyst and a water-soluble inorganic base by the use of a sulphonyl compound as a condensing reagent.