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New post-treatment technology of 5-bromo-2-chlorobenzoic acid

A new process technology for chlorobenzoic acid, which is applied in the new process field of post-treatment of 5-bromo-2-chlorobenzoic acid, and can solve problems such as unsuitable scale-up production and flushing accidents

Inactive Publication Date: 2017-09-15
NANTONG NABAIYUAN CHEM +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The experiment was relatively stable in the small test stage, but when the pilot test was carried out, a serious punching accident occurred, which is not suitable for further scale-up production

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] At room temperature, add 46g solid 2-chlorotrichlorotoluene (0.2mol, 1eq) and 50mL dichloromethane to a 250mL reaction flask, dissolve under magnetic stirring, and then add 5.92g FeBr 3 (0.02mol, 0.10eq), then 35.2g Br was added dropwise 2 (0.22mol, 1.1eq), maintained at 25-30℃ for 6h, after the reaction, concentrated under reduced pressure to remove the solvent and excess Br 2 .

[0035] 180g of acetic acid (3.0mol, 15eq) was added, then the temperature was raised to 110°C for 15h. After the reaction, the temperature was lowered to below 60°C, and 120g of acetic acid was recovered by concentration under reduced pressure (recovery rate 67%).

[0036] 90g of water was added to the system, the temperature was raised to 80°C to dissolve the solid completely, then gradually cooled to 15°C, filtered, the filter cake was washed with 50 mL of water, and dried to obtain 42.0g of off-white crude product, yield 89.2%; HPLC 95.1%.

[0037] The present invention performs nuclear ...

Embodiment 2

[0039] At room temperature, add 46g solid o-chlorotrichlorotoluene (0.2mol, 1eq) and 50mL dichloromethane to a 250mL reaction flask, dissolve under magnetic stirring, then add 1.12g Fe powder (0.02mol, 0.10eq), then dropwise Add 35.2g Br 2 (0.22mol, 1.1eq), maintained at 25-30℃ for 6h, after the reaction, concentrated under reduced pressure to remove the solvent and excess Br 2 .

[0040] 120 g of propionic acid (2.0 mol, 10 eq) was added, then the temperature was raised to 120° C. for 20 h. After the reaction, the temperature was lowered to below 60° C., and 60 g of propionic acid was recovered by concentration under reduced pressure (recovery rate 50%).

[0041] 80g of water was added to the system, the temperature was raised to 80°C to completely dissolve the solid, then gradually cooled to 15°C, filtered, the filter cake was washed with 50 mL of water, and dried to obtain 41.7g of light gray crude product, yield 88.5%; HPLC 94.7%.

[0042] The present invention performs ...

Embodiment 3

[0044] At room temperature, add 46g solid o-chlorotrichlorotoluene (0.2mol, 1eq) and 50mL dichloromethane to a 250mL reaction flask, dissolve under magnetic stirring, and then add 5.92g FeBr 3 (0.01mol, 0.05eq), then 35.2g Br was added dropwise 2 (0.22mol, 1.1eq), maintained at 25-30℃ for 6h, after the reaction, concentrated under reduced pressure to remove the solvent and excess Br 2 .

[0045]Add 120 g of acetic acid (2.0 mol, 10 eq) recovered in Example 1, then heat up to 110 °C for 15 h, after the reaction, cool down to below 60 °C, concentrate under reduced pressure to recover 60 g of acetic acid (recovery rate 50%).

[0046] 80g of water was added to the system, the temperature was raised to 80°C to dissolve the solid completely, then gradually cooled to 15°C, filtered, the filter cake was washed with 50 mL of water, and dried to obtain 40.8g of off-white crude product, yield 86.6%; HPLC 93.9%.

[0047] The present invention performs nuclear magnetic resonance detectio...

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Abstract

The invention relates to a new post-treatment technology of 5-bromo-2-chlorobenzoic acid. The technology comprises the following steps: 1, reacting 2-chlorobenzotrichloride with bromine under the action of a catalyst to prepare 2-chloro-5-bromobenzotrichloride, adding an organic acid, carrying out a heating reaction, and concentrating the obtained reaction product after the reaction ends to recover the organic acid; and 2, adding water to a concentrate obtained in step 1 to precipitate crystals, and filtering the obtained solution to obtain crude 5-bromo-2-chlorobenzoic acid. The technology solves the problem of the wastewater problem of large amounts of H2SO4, HCl, ferric chloride or ferric bromide, other high-concentration acids and salts generated in the reaction and the hidden safety trouble problem in the prior art, is safe and environmentally-friendly, and is economical and practical due to the concentrated and recovered organic acid which can be directly repeatedly used.

Description

technical field [0001] The invention relates to the technical field of organic synthesis, in particular to a new post-processing process of 5-bromo-2-chlorobenzoic acid. Background technique [0002] 5-Bromo-2-chlorobenzoic acid is the starting material for the synthesis of the antidiabetic drug Dapagliflozin. [0003] The invention patent with publication number CN 105622382 A discloses a method for synthesizing 5-bromo-2-chlorobenzoic acid. Using 2-chlorotrichlorotoluene as a raw material, 5-bromo-2-chlorotoluene is obtained through bromination and hydrolysis reactions. Chlorobenzoic acid. The raw materials of this route are cheap and easy to obtain, and the total yield is high, but the problem of acid and high-salt wastewater containing sulfuric acid, hydrochloric acid and hydrobromic acid will be generated in the post-processing. The existing method for treating this waste water is to use flake alkali to neutralize first, and then evaporate the water to dryness to obta...

Claims

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Application Information

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IPC IPC(8): C07C51/093C07C63/70C07C17/12C07C25/02
Inventor 慕春明陈昌辉桑陈池黄莉朱志平孙光福谢宏徐卫清吴建树
Owner NANTONG NABAIYUAN CHEM
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