Preparation method of 4-trifluoroethoxyl pyridine-N-oxide derivative

Abstract

The invention provides a preparation method of a 4-trifluoroethoxyl pyridine-N-oxide derivative. In the method, 4-(2,2,2-trifluoroethoxyl)pyridine oxide, 2,3-dimethyl-2-(2,2,2-trifluoroethoxyl)pyridine oxide and 2-methyl-3-chlorin-4-(2,2,2-trifluoroethoxyl)pyridine oxide are prepared by taking a readily-available 4-nitro-N-pyridine oxide derivative and 2,2,2-trifluoroethanol as raw materials under the action of a strong alkali. The reaction conditions are mild, and operation is simple.

Description

technical field

[0001] The invention relates to the field of fluorine chemical industry, in particular to a synthesis method of 4-trifluoroethoxypyridine-N-oxide derivatives. Background technique

[0002] The synthetic method of 4-trifluoroethoxypyridine-N-oxide derivative mainly contains following several kinds: with 4-nitro-N-oxide pyridine derivative and various trifluoroethoxy esters (such as: trifluoro Ethoxysulfonate, trifluoroethoxybenzenesulfonate, etc.) as raw materials, hexamethylphosphoric triamide as solvent and sodium hydride reaction synthesis; with phenols and trifluoroiodoethane as starting materials, DMSO is a solvent, reacted under the action of catalyst potassium fluoride; reacts with halogenated benzene and sodium hydride, trifluoroethanol, with DMF as solvent; with nitropyridine and trifluoroethanol, potassium carbonate as raw material, acetonitrile as solvent, in The reaction is carried out under the catalysis of tetrabutylammonium bromide. In the abo...