Method for preparing 2-amino-2-methyl-1-propionic ester

A technology of propionate and methyl, applied in the field of preparation of 2-amino-2-methyl-1-propionate, can solve the problems of low conversion rate, recrystallization, long reaction holding time, etc., and achieves a wide range of sources. , the route cost is low, and the reaction steps are simple to operate.

Active Publication Date: 2015-02-11
WANHUA CHEM GRP CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the preparation method reported in this patent has problems such as too low conversion rate (only 55%), too long reaction holding time (12-48h), and the separation of the final product requires solvent washing and recrystallization, etc.
But there is no bibliographical report for the method for directly preparing 2-amino-2-methyl-1-propionate

Method used

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  • Method for preparing 2-amino-2-methyl-1-propionic ester
  • Method for preparing 2-amino-2-methyl-1-propionic ester
  • Method for preparing 2-amino-2-methyl-1-propionic ester

Examples

Experimental program
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Effect test

Embodiment 1

[0049] (1). Dimerization of dimethyl ketene: Weigh 70.04g (1.00mol) dimethyl ketene and dissolve it in 200g ethyl acetate, put the ethyl acetate solution dissolved in dimethyl ketene in 500ml In a three-necked flask, raise the temperature to 70° C., and keep it warm for 2 hours to obtain a dimerization reaction solution. Ethyl acetate was distilled off from the reaction solution at 0.02 MPa and 50° C. to obtain 69.88 g of solid.

[0050] (2). Preparation of 2,2,4,4-tetramethyl-1,3-cyclobutanedione oxime: 69.88g of the solid obtained in step (1) (based on the complete reaction of dimethyl ketene, 0.50mol ) and 70.19g (1.01mol) of hydroxylamine hydrochloride were placed in a 500ml three-necked flask containing 160g (5.00mol) of methanol, after the temperature was raised to 20°C, ammonia was slowly introduced into the reaction system under stirring, and the reaction temperature was maintained at 20°C. The pH of the system was 8-12. After continuing to pass through for 4 hours, s...

Embodiment 2

[0061] (1).Dimerization of dimethylketene: Weigh 210.12g (1.50mol) dimerization product 2,2,4,4-tetramethyl-1,3-cyclobutanedione of dimethylketene Add it into a 500ml three-necked flask, raise the temperature to 120°C, add 70.04g (1.00mol) of dimethyl ketene dropwise under normal pressure, after the addition is complete, continue to raise the temperature to 140°C, and keep it warm for 1.5h to obtain dimethicone Polymerization solution. After cooling to room temperature, 277.32 g of solid were obtained.

[0062] (2). Preparation of 2,2,4,4-tetramethyl-1,3-cyclobutanedione oxime: 69.33 g of the solid obtained in step (1) (based on the complete reaction of dimethyl ketene, 0.50 mol ) and 82.89g (1.01mol) of hydroxylamine sulfate were placed in a 1000ml three-necked flask containing 480g (15.00mol) of methanol, after the temperature was raised to 40°C, solid sodium carbonate was slowly added to the reaction system under stirring, and the reaction temperature was kept at 40°C. Th...

Embodiment 3

[0066] (1). Dimerization of dimethyl ketene: Weigh 70.04g (1.00mol) dimethyl ketene and dissolve it in 140g ethyl acetate, and place the ethyl acetate solution dissolved in dimethyl ketene in 500ml In a three-necked flask, raise the temperature to 110° C., and keep it warm for 3 hours to obtain a dimerization reaction solution. The reaction solution was evaporated to dry ethyl acetate at 0.02 MPa and 50° C. to obtain 69.45 g of solid.

[0067] (2). Preparation of 2,2,4,4-tetramethyl-1,3-cyclobutanedione oxime: 69.45 g of the solid obtained in step (1) (based on the complete reaction of dimethyl ketene, 0.50 mol ) and 68.98g (1.05mol) of hydroxylamine phosphate were placed in a 500ml three-neck flask containing 160g (5.00mol) of methanol, and after the temperature was raised to 40°C, ammonia gas was slowly introduced into the reaction system under stirring, and the reaction temperature was kept at 40°C. The pH of the system is 8-12. After continuous feeding for 2 hours, the fe...

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Abstract

The invention relates to a method for preparing 2-amino-2-methyl-1-propionic ester. The method comprises the following steps: 1) performing dimerization reaction on dimethyl ethenone to generate 2,2,4,4-tetramethyl-1,3-cycbutanedione; 2) generating 2,2,4,4-tetramethyl-1,3-cycdimethylglyoxime from 2,2,4,4-tetramethyl-1,3-cycbutanedione obtained in the step 1) and hydroxylamine in the presence of an alkali catalyst; 3) reacting 2,2,4,4-tetramethyl-1,3-cycdimethylglyoxime obtained in the step 2) with alcohol in the presence of an acid catalyst so as to generate a reaction liquid containing amino-acid ester and / or amino-acid ester salt; 4) neutralizing and converting the amino-acid ester salt in the step 3) into amino-acid ester, and purifying to obtain a product. The method is low in raw material cost, wide in resource of raw materials, simple in reaction step, gentle in reaction condition, high in yield and easy for purification of the product.

Description

technical field [0001] The invention relates to a preparation method of 2-amino-2-methyl-1-propionate, which belongs to the field of organic synthesis. Background technique [0002] Since a large number of amino acids were put into mass production in the 1970s, the application of many downstream derivatives of amino acids has been widely developed, and the synthesis and application of amino acid esters have attracted more attention. [0003] 2-Amino-2-methyl-1-propionate is widely used in the fields of synthesis of peptide chains, pharmaceutical and pesticide intermediates, food additives and coating additives, especially copper-based catalysts can be used to catalyze hydrogenation or hydroboration Preparation of 2-amino-2-methyl-1-propanol by sodium reduction method. [0004] There have been a lot of reports on the synthesis of amino acid esters at home and abroad. The main methods include direct esterification, transesterification and biological methods, among which the d...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C229/08C07C227/40C07C227/22C07C251/44C07C249/04C07C49/39C07C45/76
Inventor 叶天刘运海信勇谢增勇朱发明丛鑫董岩峰王爱发牟通袁帅王漭黎源华卫琦
Owner WANHUA CHEM GRP CO LTD
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