Zeneca Limited

Syngenta Corporation

Syngenta Crop Protection, Inc.

David John Ritchie

Raymond Vincent Jones

Alan John Whitton

Michael Charles Standen

Raymond Vincent Heavon Jones

Jennifer Ann White

Colin John Bennie

Robin Fieldhouse

Paul A Worthington

Ewan Campbell Boyd

Gordon Richard Munns

Hannah Sallie Robertson McCann

Julie Forrester

Logan Thomson Nisbet

Kirstin Maccormick

Pascal Bugnon

Paul Richard Evans

Graham A Rae

Kirstin MacCormick

Barry Stuart Crombie

Hannah Sallie McCann

3-Isochromanone is prepared by partially chlorinating o-tolylacetic acid with sulphuryl chloride or chlorine gas in an inert organic solvent in the presence of a free radical initiator. The 2-chloromethylphenylacetic acid first obtained is converted to 3-isochromanone by treatment with a base and separated from unreacted o-tolylacetic acid, which is in the form of a salt, by a phase separation technique. The separated o-tolylacetic acid salt is converted to o-tolylacetic acid by controlled acidification and the o-tolylacetic acid is extracted for re-use. The invention reduces the formation of unwanted, over-chlorinated by-products and leads to a more efficient process.

Chemical process

A process for the preparation of 3-isochromanone which comprises contacting an o-xylene-&#x3b1;,&#x3b1;'-dihalide with carbon monoxide, in the presence of a catalyst and a hindered amine base in a liquid medium comprising water and a tertiary alcohol.

Process for preparing 3-isochromanone

3-Isochromanone is prepared by contacting an o-xylene-&agr;,&agr;&prime;-dihalide with carbon monoxide in a two-phase liquid medium, in which one phase is aqueous and the other phase is water-immiscible, in the presence of a catalyst and a hindered amine base.

A process for preparing 4,6-dihydroxypyrimidine comprising the steps:

One-step process for preparing methyl 2-(halomethyl)phenylacetate from

Process for preparing 4,6-dichloro-pyrimidine

Process for the preparation of 2-(6-substituted pyrid-2-yloxymethyl)

Process for the manufacture of N-phosphonomethyliminodiacetic acid

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Falkirk, United Kingdom

David John Ritchie