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The synthetic method of 2-chloro-4-thiamphenicol benzoic acid

A kind of technology of thiamphenicol benzoic acid and synthesis method, which is applied in the field of catalyzed oxygen transfer synthesis of 2-chloro-4-thiamphenicol benzoic acid, can solve the problems of large amount of oxygen, low recovery rate of nitric acid, large amount of nitric acid, etc., to achieve High product yield, stable reaction process, simple and feasible operation

Inactive Publication Date: 2017-03-22
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] In the existing methods, oxygen is also used to reduce the amount of nitric acid, but they are all open systems, so there are defects such as large amount of oxygen, low recovery rate of nitric acid, and large amount of nitric acid.

Method used

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  • The synthetic method of 2-chloro-4-thiamphenicol benzoic acid
  • The synthetic method of 2-chloro-4-thiamphenicol benzoic acid
  • The synthetic method of 2-chloro-4-thiamphenicol benzoic acid

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] Embodiment 1, a kind of synthetic method of 2-chloro-4-thiamphenicol benzoic acid, carries out following steps successively:

[0039] 1), 5.15g (0.025mol) 2-chloro-4-thiamphenicol toluene, 25wt% nitric acid 12.60g (0.050mol), catalyst CuI (0.00125mol) 0.24g, Co 2 o 3 (0.00125mol) 0.21g was successively added into a 25mL autoclave. After the addition, the autoclave was filled with oxygen at a pressure of 3.0MPa, and the temperature was slowly raised to 200°C (about 12 minutes to complete the temperature rise). 1.8MPa, and then filled with oxygen again to a pressure of 3.0MPa, and continued to keep warm and stir for about 3 hours.

[0040] 2), stop heating, continue to stir, make the reaction product of step 1) gained to cool down to room temperature naturally, release pressure (come out a small amount of yellow smoke), transfer reaction product to 100mL beaker, slowly add dropwise 20g of 20wt%NaOH solution (about 10 minutes dropwise), stirred until the solid in the rea...

Embodiment 2～ Embodiment 20

[0043] Change catalyst CuI, Co(OAc) in embodiment 1 2 The amount, nitric acid consumption, nitric acid concentration, temperature of reaction, oxygen pressure, all the other are equal to embodiment 1, obtain embodiment 2~embodiment 20 respectively. The yield of gained 2-chloro-4-thiamphenicol benzoic acid is shown in Table 1.

[0044] Table 1

[0045]

[0046]

[0047] Note:

[0048] The content of 2-chloro-4-thiamphenicol benzoic acid obtained in Examples 2 to 20 is more than or equal to 99.2%.

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Abstract

The invention discloses a synthesizing method of 2-chloro-4-(methylsulfonyl)benzoic acid. The method includes the following steps of firstly, adding 2-chloro-4-methylsulfonyl toluene, nitric acid and catalysts into an autoclave, injecting oxygen with pressure intensity of 0 MPa to 3.0 MPa into the autoclave, heating the autoclave till the temperature reaches 140 DEG C to 200 DEG C, keeping the temperature and conducting a stirring reaction for 1 hour, injecting oxygen into the autoclave again, and continuing to keep the temperature and conduct a stirring reaction; secondly, stopping heating, dropwise adding a NaOH solution with mass concentration of 20%, conducting stirring till solid in a reaction product is not dissolved any more, and conducting filtering to adjust the pH value of filtrate to be 2 so that light yellow solid, namely, a 2-chloro-4-(methylsulfonyl)benzoic acid crude product, can be separated out; thirdly, conducting recrystallization on the 2-chloro-4-(methylsulfonyl)benzoic acid crude product through an absolute methanol hot-melting and cold-separating method to obtain the product, namely, 2-chloro-4-(methylsulfonyl)benzoic acid.

Description

technical field [0001] The invention belongs to organic synthesis, and relates to a method for synthesizing 2-chloro-4-thiamphenicol benzoic acid by catalytic oxygen transfer. Background technique [0002] 2-Chloro-4-thiamphenicol benzoic acid, which has the formula C 8 h 7 ClO 4 S, molecular weight 234, its chemical formula is shown in formula S-1. It is an important intermediate of the corn field herbicide 2-(2-chloro-4-thiamphenicol benzoyl)-1,3-cyclohexanedione (trade name sulcotrione). The chemical structure of sulcotrione is as follows: S-2 shown. [0003] [0004] According to literature reports, 2-chloro-4-thiamphenicol benzoic acid is obtained by oxidation of 2-chloro-4-thiamphenicol toluene, and the specific reaction equation is shown in formula S-3. Owing to the strong electron-withdrawing effect of the ortho-halogen group and the p-thiamphenicol group, the oxidation of 2-chloro-4-thiamphenicol toluene is relatively difficult. [0005] [0006] Current...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C315/04C07C317/44
Inventor 陈新志王玲钱超
Owner ZHEJIANG UNIV