Shell Oil Comapny

Shell Internationale Research Maatschappij, B.v.

Derek A Wood

Ronald F Mason

Roger A Sheldon

Herbert P Rosinger

Royston H Davis

Martin Harris

Peter Been

Paul H Briner

Stuart P Briggs

Diphenyl ether derivatives of formula II ##STR1## wherein R.sub.1 represents a hydrogen or halogen atom or an alkyl or haloalkyl group, R.sub.2 and R.sub.3, which may be the same or different, each independently represents a hydrogen or halogen atom, or an alkyl, haloalkyl, nitro or cyano group, R.sub.4 represents an alkyl group and X represents an oxygen or sulphur atom, useful as intermediates in the preparation of diphenyl ether herbicides, are prepared by treating a compound of formula III ##STR2## where R.sub.1, R.sub.2, R.sub.3 and X are as defined above and R.sub.6 is a hydrogen atom or an alkyl group, with an alkali under hydrolyzing conditions.

Process for preparing diphenyl ethers

A process for the preparation of 1-substituted azetidin-3-ol derivatives of the formula: ##STR1## in which R.sup.1 represents a hydrogen atom or an alkyl, aryl or aralkyl group in which the alkyl moiety contains up to eight carbon atoms, by cyclizing a solution in triethylamine of an aminoalcohol of the formula: ##STR2## in which Hal represents a halogen atom and the use of such derivatives as intermediates for the preparation of azetidine-3-carboxylic acid derivatives.

Preparation of 1-benzylazetidine-3-ol derivatives

Substituted azetidine derivatives of formula ##STR1## in which R represents chlorine, bromine, hydroxy or alkanoyloxy of up to 6 carbon atoms, processes for their preparation and their use as intermediates for the preparation of azetidine-3-carboxylic acid.

N-benzyl,3-hydroxymethyl and 3-alkanoyloxymethyl azetidine derivatives

Insecticidal 2-(nitromethylene)-tetrahydro-2H-1,3-thiazines substituted on the nitrogen atom of the ring by a sulfonyl moiety.

Insecticidal N-substituted-2-(nitromethylene)-tetrahydro-2H-1,3-thiazines

This invention relates to the preparation of cyclopropane carboxylic acid ester derivatives, which are useful as pesticides. There is provided a process for preparing a 1:1 mixture of 1R cis S- and 1S cis R- isomers substantially free of 1S cis S- and 1R cis R- isomers of a compound of formula: ##STR1## wherein R.sup.1 and R.sup.2 are each independently selected from chlorine, bromine and methyl, which process comprises dissolving a mixture of 1S cis S- and 1R cis R- isomers of the compound of formula I, alone or in the presence of 1R cis S- and 1S cis R-isomers, in organic amine base containing from 5 to 7 carbon atoms and being a secondary amine containing two branched alkyl groups or a tertiary amine, and crystallizing out from the resulting solution of cis - isomers of formula I in the organic amine base a 1:1 mixture of the 1R cis S- and 1S cis R- isomers substantially free of 1S cis S- and 1R cis R- isomers. The process of the invention yields a product which contains substantially twice as much of the most active isomer of the compound of formula I as a racemic mixture of all four cis - isomers, and is a readily effected process which does not involve any asymmetric synthesis or optical resolution steps.

Process for preparing cyclopropane carboxylic acid ester derivatives

A method for preparing a pyrethroid insecticide of general formula: ##STR1## wherein the two hydrogen atoms on the cyclopropane ring are in the cis- configuration, in which an acid of formula: ##STR2## is neutralized with a water-soluble base and then reacted in the presence of a phase-transfer catalyst with a solution in a substantially water-immiscible organic solvent of an alpha-cyanobenzyl aryl sulphonate of formula: ##STR3## the substituents in the formulae having the following meanings; A represents an optionally substituted aryl group; R.sub.1 and R.sub.2 represent hydrogen or halogen; and R.sub.3 and R.sub.4 represent chlorine, bromine, or methyl.

Preparation of cyanobenzyl cyclopropane carboxylates

Mixtures of the geometric isomeric forms of 3-azabicyclo-(3.1.0)hexane-2-carbonitrile are resolved by selective extraction of a mixture of their benzenesulfonic acid salts or their toluenesulfonic acid salts.

Separation of isomers

Phenoxybenzyl esters are prepared by neutralizing an aqueous solution of a carboxylic acid and contacting the neutralized solution with a solution of phenoxybenzyl halide in a water-immiscible base in the presence of a phase transfer catalyst.

Preparation of phenoxybenzyl esters

Certain carboxylic acid esters also containing a cyano group are prepared by reacting an acid halide, an aldehyde and a water-soluble cyanide in the presence of a water immiscible aprotic solvent and preferably a phase-transfer catalyst.

Preparation of esters

Meta-aryloxybenzaldehydes are prepared by treating a mixture of meta-aryloxybenzyl- and benzal halides with hexamethylenetetramine (or equivalent amounts of ammonia and formaldehyde) and hydrolyzing the resulting product under acid conditions.

Preparation of meta-aryloxy-benzaldehydes

Alkyl esters of 3-cyano-3-(3-phenoxyphenyl)-2-ketopropionic acid, useful as precursors for the preparation of insecticidal esters of 3-phenoxy-.alpha.-cyanobenzyl alcohol.

Precursors for insecticides

3-PHENOXYBENZYL BROMIDE IS PREPARED BY TREATING 3-PHENOXYTOLUENE WITH BROMINE IN THE PRESENCE OF ULTRA-VIOLET RADIATION, AT A TEMPERATURE IN THE RANGE OF FROM 180.degree. C to 250.degree. C.

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Sittingbourne, United Kingdom

Derek A Wood