Zeneca Limited

Syngenta Corporation

Other

Npil Pharmaceuticals (uk) Limited

Stephen Martin Brown

Martin Charles Bowden

Brian David Gott

James Peter Muxworthy

Thomas Gray

Seyed Mehdi Tavana

Andrew John Blacker

Alfred Glyn Williams

Trevor R Perrior

John Heathcote Atherton

Martin Lennon

Howard Rawlinson

Allan Michael Jordan

Raymond Vincent Jones

Christopher John Urch

Dick De Vos

John David Jones

Raymond Vincent Heavon Jones

Brian Geoffrey Cox

Derek Raymond Boyd

Gareth Andrew DeBoos

Louie A Nady

Douglas John Smith

Keith Moorhouse

Ian Jeffrey Priestley

Thomas William Bentley

Masao Tuskazaki

Robert Oliver Jones

Paul Richard Giles

Ian Andrew Lilley

Alan Th McGown

Istvan Ettienne Marko

Jonathan Michael Jeremy Williams

Gary N Sheldrake

Christian Bubert

Nicholas J Lawrence

Jonathan William Wiffen

A process for the preparation of gamma-cyhalothrin comprising steps of a) chlorinating 1R cis-Z 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopropanecarboxylic acid to give 1R cis-Z 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopropanecarboxylic acid chloride and b) esterifying 1R cis-Z 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopropanecarboxylic acid chloride with the (S)-cyanohydrin of 3-phenoxy benzaldehyde (III).

Process for preparing gamma-cyhalothrin

A process for the preparation of gamma-cyahlothrin comprising a) chlorinating 1R cis-Z 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopropanecarboxylic acid to give 1R cis-Z 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopropanecarboxylic acid chloride; b) esterifying 1R cis-Z 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopropanecarboxylic acid chloride with 3-phenoxy benzaldehyde in the presence of a source of cyanide to form a diastereoisomeric mixture of cyhalothrin isomers and c) epimerising the diastereoisomeric mixture under conditions in which the least soluble diastereoisomer crystallises from solution.

Production process of gamma-cyhalothrin

A catalytic transfer hydrogenation process is provided. The catalyst employed in the process is a metal hydrocarbyl complex which is coordinated to defined bidentate ligands substituted with at least one group selected from an optionally substituted sulphonated hydrocarbyl group, a sulphonated perhalogenated hydrocarbyl group, or an optionally substituted sulphonated heterocyclyl group. Preferred metals include rhodium, ruthenium and iridium. Preferred bidentate ligands are diamines and aminoalcohols, particularly those comprising chiral centres. The hydrogen donor is advantageously a secondary alcohol or a mixture of triethylamine and formic acid. The process can be employed to transfer hydrogenate ketones and imines, which are preferably prochiral. Catalysts for use in such a process are also provided.

Transfer hydrogenation process and catalyst

A process for the preparation of 4-methyl-2,3,5,6-tetrafluorobenzyl alcohol comprising hydrogenating 4-methyl-2,3,5,6-tetrafluorobenzonitrile to 4-methyl-2,3,5,6-tetrafluorobenzylamine and converting 4-methyl-2,3,5,6-tetrafluorobenzylamine to 4-methyl-2,3,5,6-tetrafluorobenzyl alcohol. The process optionally also comprises the further step of reacting 4-Methyl-2,3,5,6-tetrafluobenzyl alcohol with cis-Z-3-(2-chloro-1,1,1-trifluoro-2-propenyl)-2,2-dimethylcyclopropanecarbonyl chloride to the form tefluthrin. 4-Methyl-2,3,5,6-tetrafluorobenzylamine and salts thereof are also claimed.

Preparation of 4-methyl-2,3,5,6-tetrafluorobenzyl alcohol

A process for producing compounds of formula (VIIa) and (VIIb) wherein X is a leaving group; Y and Yare idependently Cl or Br; and Z is Cl, Br or a haloalkyl group which process comprises a) reacting a compound of formula (VII) wherein X, Y, Yand Z are as defined for compounds (VIIa) and (VIIb) with a substantially optically pure chiral amine in a solvent to form a diastereoisomeric salt; b) separating the diastereomeric salt of each enantiomer; c) converting the diastereomeric salt of each anantiomer separately to compounds of formulae (VIIa) and (VIIb) respectively by acid or base hydrolysis, the use of the compounds in making pyrethroid insecticides and novel intermediates.

Process for the preparation of enantiomerically pure pyrethroid insecticides

A process for producing fomesafen from acifluorfen comprises the steps of (a) converting acifluorfen to its acid chloride, (b) coupling the acid chloride so formed with methanesulphonamide to form crude fomesafen and (c) purifying the crude fomesafen, characterized in that each of the steps is carried out in a single common solvent, which is preferably a chloroalkane. Preferably the steps are telescoped together so that there is no isolation of the product for any step until fomesafen is obtained.

Process for the preparation of diphenyl ether compounds

A process for the preparation of 3,5-dichloropyridine comprising reacting a trichloropyridine, a tetrachloropyridine or pentachloropyridine with zinc metal, in the presence of an acidic compound and at a temperature in the range 50-120&deg; C.

Chemical process

A process for preparing a compound of formula (IV), wherein R,is C,alkyl, CH,(C,haloalkyl), benzyl, CH,(C,akenyl or CH,(C,alkynyl), which comprises reducing a compound of formula (III). Compounds of formula (IV) are agrochemical intermediates.

Process for the preparation of 8-azabicyclo(3.2.1)octane derivatives

A process for preparing a compound of formula (IV) wherein R,is C,alkyl, C,haloalkyl, benzyl, C,alkenyl or C,alkyny, (provided that the &agr;-carbon atom of R,is neither unsaturated nor substituted with halogen), which comprises reacting a compound of formula (III) with a source of hydroxylamine in the presence of an acid. Compounds of formula (IV) are agrochemical intermediates.

Process for the preparation of substituted 8-azabicyclo&lsqb;3,2,1&rsqb;octanes

The object of the present invention is the development of new chiral auxiliaries for improved &bgr;-lactam formation that control both the diastereoselectivity of &bgr;-lactam formation and which can be removed without destruction of the sensitive azetidinone ring, providing valuable intermediates for coupling to the C-13 hydroxyl group of anti-tumor taxanes, such as paclitaxel. Further, the object of the present invention is enantiomerically pure (S)-(&minus;)-1-(p-methoxy-phenyl)propyl-1-amine.

Synthesis of new &bgr;-lactams

Process for the preparation of acylated cyclic 1,3-dicarbonyl compounds

5-Chloro-2-(4,4-difluorobutylthio)thiazole is prepared from 2-mercaptotriazole by a multistep process involving S-alkylation, chlorination and dehydrochlorination and is converted by oxidation to the corresponding sulfone which is useful as an agricultural nematicide.

Process

The present invention provides the novel chlorofluorohydrocarbon 1,1-difluoro-1,4-dichlorobutane, and a process for its preparation comprising reacting 1,1,1,4-tetrachlorobutane or 1,1,4-trichlorobut-1-ene with hydrogen fluoride in the liquid or vapor phase. The product has useful solvent properties and is also useful in synthetic chemistry for the introduction of fluorocarbon functionality.

Chlorofluorohydrocarbon and process thereto

A process for the purification of a compound of general formula I: ##STR1## wherein R.sup.1 is hydrogen or C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl or C.sub.2 -C.sub.6 alkynyl, any of which may optionally be substituted with one or more substituents selected from halogen and hydroxy; or COOR.sup.4, COR.sup.6, CONR.sup.4 R.sup.5 or CONHSO.sub.2 R.sup.4 ; R.sup.4 and R.sup.5 independently represent hydrogen or C.sub.1 -C.sub.4 alkyl optionally substituted with one or more halogen atoms; R.sup.6 is a halogen atom or a group R.sup.4 ; R.sup.2 is hydrogen or halo; and R.sup.3 is C.sub.1 -C.sub.4 alkyl, C.sub.2 -C.sub.4 alkenyl or C.sub.2 -C.sub.4 alkynyl, any of which may optionally be substituted with one or more halogen atoms; or halo; or, where appropriate, a salt thereof; from a mixture containing the compound of general formula I together with one or more isomers or di-nitrated analogues thereof; the process comprising dissolving the mixture in a suitable crystallisation solvent and recrystallising the product from the resulting crystallisation solution wherein the crystallisation solution contains not more than 25% loading of the compound of general formula I, loading being defined as: ##EQU1## and wherein the temperature to which the solution is cooled for crystallisation is not greater than about 30.degree. C.; wherein, after the addition of the crystallising solvent but before recrystallisation, the crystallisation solution is subjected to at least one wash with an aqueous solution having an acid pH followed by back extraction with fresh crystallising solvent. The process is particularly useful for purifying acifluorfen produced via a route starting with m-cresol.

Purification process

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Huddersfield, United Kingdom

Stephen Martin Brown