Preparation method of trans-D-chrysanthemic acid

Abstract

A preparation method of trans-D-chrysanthemic acid relates to an improvement of the preparation method of trans-D-chrysanthemic acid. The invention provides a preparation method with easy operation of trans-D-chrysanthemic acid. The method of the invention comprises the following steps: (1) dissolving D-(-)phenylglycine ester.HCl in water, dissolving mixed trans-chrysanthemic acid in organic solvent; or after dissolving mixed trans-chrysanthemic acid in organic solvent, once adding D-(-)phenylglycine ester.HCl; mixing the two solutions, adjusting the pH value to 5-9 with weak base, wherein the molar ratio of mixed trans-chrysanthemic acid to D-(-)phenylglycine ester.HCl is 1.5-2.5:1; (2) precipitating D-(-)phenylglycine ester.trans-D-chrysanthemic acid double salt at 0-40 DEG C; (3) separating the double salt generated in the step (2), placing in an acidic aqueous solution with the pH value of 1-4, standing for standby; and separating to obtain the trans-D-chrysanthemic acid product, neutralizing the acidic aqueous solution of D-(-)phenylglycine ethyl ester with weak base to recycle D-(-)phenylglycine ester.HCl.

Description

Technical field:

[0001] The present invention relates to the improvement of the preparation method of trans-D-chrysanthemic acid. Background technique:

[0002] At present, the active ingredients widely used in household sanitation insecticides are pyrethroids represented by allethrin, which are highly efficient and low in toxicity, and are harmless to humans and animals. The key intermediate for the synthesis of such insecticides is chrysanthemic acid , it has a variety of isomers, among which the permethrin ester formed by trans chrysanthemic acid has the highest insecticidal effect, and the common method to obtain trans chrysanthemic acid is to separate and obtain it . Such as: (R)-(+)-1-amino-1,4a-dimethyl-7-isopropyl-1,2,3,4,4a,9,10,10a-octahydrophenanthrene (South China Journal of Polytechnic University, 27 (3), 100-105, 1999), L-lysine (German patent 2043137, 1971), ephedrine (European patent 68736, 1981), (-)-cis-benzyl-( 2-Hydroxymethylcyclohexyl)amine (Japanese ...