Method for preparing 4, 6 dichloropyridine

Abstract

The present invention relates to a method capable of using diphosgene or triphyosgene to chlorinate 4,6-dihydroxypyrimidine to obtain 4,6-dichloropyrimidine in the presence of proper alkali and a certain solvent or mixed solvent.

Description

field of invention

[0001] The present invention relates to the conversion of 4,6-dihydroxypyrimidine to 4,6-dichloropyrimidine using diphosgene or triphosgene in the presence of a suitable base. 4,6-dichloropyrimidine can be used as a chemical intermediate in the pesticide and pharmaceutical industries, such as the preparation of the fungicide azoxystrobin, nucleoside analogs and compounds active in the central nervous system (CNS). Background technique

[0002] Because of the widespread use and economic importance of 4,6-dichloropyrimidines, many methods have been developed for the synthesis of chlorinated pyrimidines, especially 4,6-dichloropyrimidines.

[0003] WO 02 / 04428 (Chinese patent 01812416.X) discloses a reaction of organic amide (such as formamide, acetamide) and phosgene, or by the reaction of organic nitrile (such as butyronitrile) and hydrogen chloride to generate imidoyl chloride compound, imide A method for producing 4,6-dichloro...