Method for preparing p-nitrobenzyl 2-diazoacetoacetate

A technology of ethyl diazo acetoacetate and diazo acetoacetic acid, applied in the field of fine chemical synthesis, can solve the problems of complex process operation, expensive catalyst, high nitrogen price, etc., achieve high purity, solve safety and occupational health problems, Simple to use effects

Active Publication Date: 2018-01-09
台州科金中高技术转移有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0010] In the first method, the product yield is only 69.2%, and the diazotization reagent p-toluenesulfonyl azides is an explosive product and the price of nitrogen is expensive
[0011] The sodium azide used in the second method is a controlled explosive, and methanesulfonyl chloride is a highly toxic substance, both of which are expensive and difficult to obtain.
[0012] The 2-diazoacetoacetic acid used in the third method has no industrial products at present, and the catalyst used is expensive and the process operation is complicated

Method used

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  • Method for preparing p-nitrobenzyl 2-diazoacetoacetate
  • Method for preparing p-nitrobenzyl 2-diazoacetoacetate
  • Method for preparing p-nitrobenzyl 2-diazoacetoacetate

Examples

Experimental program
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Effect test

Embodiment 1

[0030] Add 275.7g (1.8mol) p-nitrobenzyl alcohol, 337.3g (2.16mol) ethyl 2-diazoacetoacetate, 2.8g sodium ethylate and 1380g toluene in the 3000ml reaction bottle with fractionation device, be warming up to reflux, Slowly collect ethanol fractions, react for 5.5 hours, drop to 0-10°C, keep stirring for 1 hour, filter, and dry to obtain 460g of 2-diazoacetoacetic acid p-nitrobenzyl ester product, yield 97.1%, HPLC: 99.8% .

Embodiment 2

[0032] Add 30.6g (0.2mol) p-nitrobenzyl alcohol, 46.8g (0.3mol) ethyl 2-diazoacetoacetate, 0.3g concentrated sulfuric acid and 245g xylene in a 500ml reaction flask with a fractionation device, and heat up to reflux , slowly collect the ethanol fraction, after reacting for 4 hours, lower the temperature to 20-30°C, keep stirring for 30 minutes, filter, and dry to obtain 50.8g of p-nitrobenzyl 2-diazoacetoacetate product, the yield is 96.5%, HPLC: 99.8 %.

Embodiment 3

[0034] Add 38.3g (0.25mol) p-nitrobenzyl alcohol, 46.8g (0.3mol) ethyl 2-diazoacetoacetate, 0.8g p-toluenesulfonic acid and 230g toluene in the 500ml reaction bottle that has fractionation device, be warming up to Reflux, slowly collect the ethanol fraction, react for 6 hours, drop to 10-20°C, keep stirring for 1 hour, filter, and dry to obtain 62.8g of p-nitrobenzyl 2-diazoacetoacetate, yield 95.5%, HPLC: 99.2 %.

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Abstract

The invention relates to a method for preparing p-nitrobenzyl 2-diazoacetoacetate. The method takes p-nitrobenzyl alcohol and 2-diazoacetoacetate as raw materials, and ester exchange one-step reactionis carried out under the catalysis of acid or alkali to prepare the p-nitrobenzyl 2-diazoacetoacetate. The preparation method provided by the invention has the advantages of less investment, simplicity in operation, no highly toxic or explosive raw materials, greenness and cleanness and the like and is suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of synthesis of fine chemicals, and in particular relates to a method for preparing p-nitrobenzyl 2-diazoacetoacetate. Background technique [0002] 2-p-nitrobenzyl diazoacetoacetate is an important pharmaceutical intermediate. For example, imipenem and panipenem both need 2-p-nitrobenzyl diazoacetoacetate as the starting material. However, there are various disadvantages in the preparation techniques related to p-nitrobenzyl 2-diazoacetoacetate at present. [0003] At present, there are mainly three methods for preparing p-nitrobenzyl 2-diazoacetoacetate: [0004] 1) The first method (published in GB:2173801) uses p-nitrobenzyl alcohol and methyl acetoacetate as starting materials, p-toluenesulfonyl azide as a diazotization reagent, and undergoes a two-step reaction of transesterification and diazotization Preparation of p-nitrobenzyl 2-diazoacetoacetate. [0005] [0006] 2) The second method (publis...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C245/18
Inventor 熊轶钟智奎
Owner 台州科金中高技术转移有限公司
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