Syngenta Corporation

Zeneca Limited

James Peter Muxworthy

Stephen Martin Brown

Brian David Gott

David Anthony Jackson

John Heathcote Atherton

Mark Robert Sykes

Martin Lennon

Gareth Andrew DeBoos

Gilbert Rodriguez

Kambiz Javdani

Beverley Ann Wilde

Graham McDougald

Ian Jeffrey Priestley

The present invention relates to improvements in processes towards the production 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid, which is a useful intermediate in fungicide production. In particular, the invention relates to a process for treating a compound of formula III, wherein Ris C-Calkyl and Ris CF, CFH or CFH, comprising the steps of a) contacting a compound of formula III with base, and b) separating the compound of formula III and the base. 

Process for purification of 1-methylpyrazole-4-carboxylic acid esters

A method for removing impurities from 2-nitro-4-methylsulfonylbenzoic acid which comprises at least two of the following steps, in any order, (a) dissolving 2-nitro-4-methylsulfonylbenzoic acid in water at a pH of about 2 to 10, followed by filtration; (b) contacting an aqueous solution of 2-nitro-4-methylsulfonylbenizoic acid with activated carbon at a pH of about 2 to 10; (c) treating an aqueous solution of 2-nitro-4-methylsulfonylbenzoic acid with sufficient base to hydrolyze undesired nitro and dinitro substituted impurities; followed by maintaining the resulting aqueous solution comprising 2-nitro-4-methylsulfonylbenzoic acid at a temperature of up to about 95&#xb0; C., and adjusting the pH of said solution to about a pH which is sufficient to effect crystallization of 2-nitro-4-methylsulfonylbenzoic acid upon cooling.

Purification of 2-nitro-4-methylsulphonylbenzoic acid

The present invention relates to a compound of the general formula: wherein Ris a 4-pyrimidinyl ring substituted at the 6-position by halo, hydroxy, 2-cyanophenoxy, 2,6-difluorophenoxy, 2-nitrophenoxy or 2-thiocarboxamidophenoxy and wherein Ris any group which can be transesterified to form a methyl ester. The present invention is also directed to a process of preparing said compound.

Process for the preparation of azoxystrobin and analogues thereof

A process for the preparation of a compound of the general formula (I): wherein Ris a 4-pyrimidinyl ring substituted at the 6-position by halo, hydroxy, 2-cyanophenoxy, 2,6-difluorophenoxy, 2-nitrophenoxy or 2-thiocarboxamidophenoxy and Ris any group which can be transesterified to form a methyl ester, which comprises treating a compound of general formula (II): wherein Rand Rhave the meanings given above, with a formylating agent and subsequently treating the formylated product with a methylating agent 

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

Process for the production of sulphonamides

A process for the preparation 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 OH; or COOR.sup.4, COR.sup.6, CONR.sup.4 R.sup.5 or CONHSO.sub.2 R.sup.4 ;

Process for the nitration of diphenylethers

A process for the nitration of an aromatic or heteroaromatic compound with a nitrating agent comprising nitric acid or a mixture of nitric and sulphuric acids, characterised in that nitration is performed in a solvent comprising at least 50% v/v of a C.sub.1 -C.sub.6 alkyl ester of a C.sub.1 -C.sub.4 carboxylic acid. The process is of particular use for the nitration of diphenyl ethers to give compounds which are useful as herbicides or as intermediates in the synthesis of herbicides.

Nitration process

A process for the preparation of an N-(alkylsulphonyl)amide, the process comprising reacting a primary amide with a sulphonyl halide in the presence of a base which is sufficiently strong to cause at least partial deprotonation of the amide.

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Huddersfield, United Kingdom

James Peter Muxworthy