Synthesis method for organic synthesis of intermediate N-acetyl-L-leucine

Abstract

The invention relates to a synthesis method for organic synthesis of an intermediate N-acetyl-L-leucine. The method mainly includes the steps of: adding 2mol leucine, 3-3.5mol p-chloroacetanilide and3-4mol phenylacetyl into a reaction container, raising the solution temperature to 60-65DEG C, performing reflux for 80-110min, conducting standing for 2-3h, lowering the solution temperature to 10-15DEG C, conducting cooling crystallization, filtering the crystal, conducting washing with a potassium bromide solution, a triethylamine solution and a nitromethane solution respectively, and performing dehydration with a dehydrating agent, thus obtaining the finished product N-acetyl-L-leucine.

Description

technical field

[0001] The invention relates to a method for synthesizing an organic synthesis intermediate N-acetyl-L-leucine. Background technique

[0002] N-acetyl-L-leucine is an important fine organic chemical intermediate, widely used in medicine, pesticide, chemical industry and other fields. But existing synthetic method adopts acetic acid to do reactant mostly, and process is more complicated, and final yield is not very high, therefore, be necessary to propose a kind of new synthetic method, this is for further improving the quality of product and yield, reduces The by-product content is of great economic importance. Contents of the invention

[0003] The object of the present invention is to provide a kind of synthetic method of organic synthesis intermediate N-acetyl-L-leucine, comprising the steps:

[0004] (i) Add 2 mol of leucine, 3-3.5 mol of p-chloroacetanilide, and 3-4 mol of phenylacetyl into the reaction vessel, raise the temperature of the solution t...

Examples

example 1

[0011] Add 2 mol of leucine, 3 mol of p-chloroacetanilide, and 3 mol of phenylacetyl into the reaction vessel, raise the temperature of the solution to 60°C, reflux for 80 minutes, let it stand for 2 hours, lower the temperature of the solution to 10°C, cool and crystallize, and filter the crystals , mass fraction is 10% potassium bromide solution washing, mass fraction is 75% triethylamine solution washing, mass fraction is 85% nitromethane solution washing, calcium oxide dehydrating agent is dehydrated, and finished product N-acetyl-L-leucine is obtained Acid 307.94g, yield 89%.

example 2

[0013] Add 2mol of leucine, 3.2mol of p-chloroacetanilide, and 3.5mol of phenylacetyl into the reaction vessel, raise the temperature of the solution to 62°C, reflux for 90min, let stand for 2.5h, lower the temperature of the solution to 12°C, cool and crystallize , filter the crystals, wash with a mass fraction of 12% potassium bromide solution, wash with a mass fraction of 77% triethylamine solution, wash with a mass fraction of 87% nitromethane solution, and dehydrate with anhydrous potassium carbonate dehydrating agent to obtain the finished product N-acetyl -L-leucine 314.86g, yield 91%.

example 3

[0015] Add 2mol of leucine, 3.5mol of p-chloroacetanilide, and 4mol of phenylacetyl into the reaction vessel, raise the temperature of the solution to 65°C, reflux for 110min, let stand for 3h, lower the temperature of the solution to 15°C, cool and crystallize, and filter The crystals were washed with 15% potassium bromide solution, 80% triethylamine solution, 90% nitromethane solution, and dehydrated by calcium oxide dehydrating agent to obtain the finished product N-acetyl-L-bright Amino acid 325.24g, yield 94%.

technical field

[0001] The invention relates to a method for synthesizing an organic synthesis intermediate N-acetyl-L-leucine. Background technique

[0002] N-acetyl-L-leucine is an important fine organic chemical intermediate, widely used in medicine, pesticide, chemical industry and other fields. But existing synthetic method adopts acetic acid to do reactant mostly, and process is more complicated, and final yield is not very high, therefore, be necessary to propose a kind of new synthetic method, this is for further improving the quality of product and yield, reduces The by-product content is of great economic importance. Contents of the invention

[0003] The object of the present invention is to provide a kind of synthetic method of organic synthesis intermediate N-acetyl-L-leucine, comprising the steps:

[0004] (i) Add 2 mol of leucine, 3-3.5 mol of p-chloroacetanilide, and 3-4 mol of phenylacetyl into the reaction vessel, raise the temperature of the solution t...

Examples

example 1

[0011] Add 2 mol of leucine, 3 mol of p-chloroacetanilide, and 3 mol of phenylacetyl into the reaction vessel, raise the temperature of the solution to 60°C, reflux for 80 minutes, let it stand for 2 hours, lower the temperature of the solution to 10°C, cool and crystallize, and filter the crystals , mass fraction is 10% potassium bromide solution washing, mass fraction is 75% triethylamine solution washing, mass fraction is 85% nitromethane solution washing, calcium oxide dehydrating agent is dehydrated, and finished product N-acetyl-L-leucine is obtained Acid 307.94g, yield 89%.

example 2

[0013] Add 2mol of leucine, 3.2mol of p-chloroacetanilide, and 3.5mol of phenylacetyl into the reaction vessel, raise the temperature of the solution to 62°C, reflux for 90min, let stand for 2.5h, lower the temperature of the solution to 12°C, cool and crystallize , filter the crystals, wash with a mass fraction of 12% potassium bromide solution, wash with a mass fraction of 77% triethylamine solution, wash with a mass fraction of 87% nitromethane solution, and dehydrate with anhydrous potassium carbonate dehydrating agent to obtain the finished product N-acetyl -L-leucine 314.86g, yield 91%.

example 3

[0015] Add 2mol of leucine, 3.5mol of p-chloroacetanilide, and 4mol of phenylacetyl into the reaction vessel, raise the temperature of the solution to 65°C, reflux for 110min, let stand for 3h, lower the temperature of the solution to 15°C, cool and crystallize, and filter The crystals were washed with 15% potassium bromide solution, 80% triethylamine solution, 90% nitromethane solution, and dehydrated by calcium oxide dehydrating agent to obtain the finished product N-acetyl-L-bright Amino acid 325.24g, yield 94%.

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