Zeneca Limited

Syngenta Crop Protection, Inc.

Louie A Nady

Gilbert Rodriguez

Stephen Martin Brown

Brian David Gott

Thomas Gray

Alan Henry Benke

Seyed Mehdi Tavana

Kambiz Javdani

Peter Karl Wehrenberg

Ping H Sih

Timothy J Doyle

The invention provides a process for synthesizing chlorinated pyrimidines. The process includes reacting imidoyl chloride compounds with phosgene (COCl). The imidoyl chloride compounds can be supplied as starting materials or can be produced by reacting organic amides with phosgene or reacting organic nitrites with hydrogen chloride. Phosgene may be replaced by equivalent reagents. The chlorinated pyrimidines, such as 4,6-dichloropyrimidine, can be used to synthesize other compounds useful in a variety of compositions, such as fungicides, pesticides, and pharmaceuticals.

Synthesis of chlorinated pyrimidines

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

Aromatic azomethines are produced by continuous reaction of an aniline with a formaldehyde source, with continuous evaporation to remove residual water of reaction. The azomethine product may be further reacted, either continuously or in batch process, with a haloacetylating agent, and, additionally, with an aliphatic alcohol.

Process for the production of azomethines and alpha-haloacetanilides

Growing community of inventors

Daphne, AL, United States of America

Louie A Nady