Preparation method of 4-AA key intermediate epoxy butylamide

The invention relates to a preparation method of 4-AA key intermediate epoxy butylamide. The preparation method comprises the steps that (1) synthesis of epoxy butyric acid is conducted: a starting material L-threonine is cyclized under diazotization and strong alkaline conditions to obtain the epoxy butyric acid; (2) synthesis of amino compounds is conducted: aminoanisole and chloroacetyl compounds (including ketone and esters) under the action of organic base are refluxed and react to obtain the amino compounds; and (3) synthesis of the epoxy butylamide is conducted: under the catalytic activation of acyl chloride, an amidation of the epoxy butylamide and the amino compounds is conducted to obtain the target product epoxy butylamide. The preparation method has the technical advantages that dosage of alkali and water is greatly reduced, dosage of organic extractants is correspondingly reduced, and at the same time, use of a phase transfer catalyst is avoided; the cost of raw materialsis lowered, and reaction