Study On The Synthesis Of The4-methanesulfonyl-amino-2-amino Acid Benzoate Key Intermediate

4-methanesulfonyl-amino-2-amino acid benzoate belongs to sulfonylurea herbicides, canbe removed efficiently between farmland weeds. Its unique mechanism of action, spectrum,efficient, environmentally friendly, and has excellent holding effect, and safety to mammals.3-amino-4-Synthetic methoxycarbonyl benzylamine is4-methanesulfonyl amino-2-amino acidmethyl benzene key step preparation process, the product is still under patent protection period,Its technology is mastered Bayer, therefore, the synthesis of the intermediates has far-reachingsignificance.This paper reviews the4-methanesulfonyl-amino-2-amino acid acid methyl ester synthesis intermediates,through theoretical analysis and research, design4-mesylamino-2-amino acid acid methyl ester intermediate3-amino-4-synthesis methoxycarbonyl benzylamine: nitrile in toluene as raw material, mixed acid nitrationto give4-methyl-3-nitrobenzene cyanide, and then to be used as oxidizing agent potassium dichromateoxidation reaction to give4-cyano-2-nitrobenzoic acid, and then methyl iodide as a reagent for methylationreaction to give the corresponding product4-cyano-2-nitro benzoate, and then hydrogenation, to obtain thefinal product3-amino-4-methoxycarbonyl-benzyl amine.The results showed that: Preparation of4-methyl-3-nitrobenzene the reaction of cyanide, the choice of65%concentrated nitric acid nitration reagent material ratio n (HNO3): n (starting material)=1:1, thereaction temperature is-15℃, with vigorous stirring,93.0%yield,98.8%purity; oxidation reaction,selected dichromate-potassium permanganate system, material ratio n (potassium dichromate)/(4-methyl-3-nitrophenyl cyanide)=1.3:1, the amount of catalyst n (KMnO4): n (starting material)=0.06:1,Catalyst greatly shorten the reaction time (24h, literature48h),the temperature is dropping-15℃, the solventis80%concentrated sulfuric acid. Yield:51.5%, purity:98.3%; methylation reaction using DMF as thesolvent, methyl iodide as a reagent, n (CH3I): n (starting material)=2:1, DBU as a catalyst and as both acidbinding agent involved in the reaction, the optimum amount of DBU n (DBU): n (raw)=2:1, the reactiontemperature is25℃, the yield:91%, purity:98.9%, mp89.1-89.3℃. Reduction reaction, the solvent ismethanol, the amount of methanol v (methanol): m (starting material)=20:1, platinum oxide as catalyst, n(catalyst): n (starting material)=2:100, the reaction pressure of2MPa, the reaction temperature is25℃,the yield was88.2%this step, the melting point of188.2~190.0℃.