Patent ID: 9598429
Date: 2017-03-21
CPC Classifications: C07D

Claim:
1. A method for synthesizing Milbemycin oxime, wherein the method comprises the following steps: (1) oxidizing reaction: oxidizing Milbemycin using hypochlorite or chlorite as oxidizers and piperidine nitrogen oxygen free radicals as a catalyst, wherein the catalyst is selected from the group consisting of 2,2,6,6-tetramethylpiperidide-N-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidide-N-oxyl, 4-methoxy-2,2,6,6-tetramethylpiperidide-N-oxyl, 4-acetyl 2,2,6,6-tetramethylpiperidide-N-oxyl, and 4-azyl-2,2,6,6-tetramethylpiperidide-N-oxyl, and halide as a catalyst promoter, wherein the oxidation reaction is conducted in a dichloromethane solvent for 0.5-4 hours at −5-15*C, to produce an intermediate product Milbemycin ketone (2) oximation reaction: reacting the Milbemycin ketone with a hydroxylamine hydrochloride oximation agent in a methyl alcohol and 1,4-dioxane reaction solvent for 10-16 hours at 25-35° C. to obtain Milbemycin oxime wherein R is methyl or ethyl.