Preparation method of methyl 2, 3-diaminobenzoate

A technology of methyl diaminobenzoate and nitrobenzoic acid, which is applied in the field of preparation of methyl 2,3-diaminobenzoate, can solve problems such as low purity, high raw material prices, and risk of explosion, and achieve a synthetic route Short, simple preparation method, easy to handle and purification effect

Active Publication Date: 2022-03-01
HANGZHOU GUORUI BIO TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

This patent uses 3-nitrophthalic acid as a raw material to prepare methyl 2,3-diaminobenzoate. The disadvantages are: the product prepared by this method has low purity, many impurities, and the price of raw materials is far away. High, high cost, the use of dangerous materials such as sodium azide reaction, high operating requirements, risk of explosion, not conducive to large-scale industrial production, the product lacks market competitiveness

Method used

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  • Preparation method of methyl 2, 3-diaminobenzoate
  • Preparation method of methyl 2, 3-diaminobenzoate
  • Preparation method of methyl 2, 3-diaminobenzoate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036]

[0037] (1) Synthesis of 3-amino-2-nitrobenzoic acid (2):

[0038] Add 150mL of purified water and 0.83g (0.006mol) of copper chloride to a 250mL four-necked bottle, then add 25g (0.124mol) of 3-chloro-2-nitrobenzoic acid, stir, and feed ammonia gas (flow rate 0.1ml Every minute), be warming up to 120 ℃, insulation reaction 6 hours, treat that reaction finishes, close ammonia gas, cool down, crystallize, filter, dry to obtain 21.3g of 3-amino-2-nitrobenzoic acid, purity is 97.4%, yield The rate is 92.8%.

[0039] (2) Synthesis of 3-amino-2-nitrobenzoic acid methyl ester (3):

[0040] Add 50.0 g (0.273 mol) of 3-amino-2-nitrobenzoic acid and 800 mL of methanol into a 1000 mL four-neck flask, resulting in a yellow turbid system. Control the temperature at 20-30°C, add 40.1g (0.410mol) of concentrated sulfuric acid, raise the temperature to 70-75°C, stir for 4 hours, then cool down to below 5°C. Control the temperature T≤5°C, add sodium hydroxide to adjust the pH of...

Embodiment 2

[0044]

[0045] (1) Synthesis of 3-amino-2-nitrobenzoic acid (2):

[0046] Add 150mL of purified water and 16.7g (0.124mol) of copper chloride to a 250mL four-necked bottle, then add 25g (0.124mol) of 3-chloro-2-nitrobenzoic acid, stir, and feed ammonia gas (flow rate 0.1ml Every minute), be warming up to 120 ℃, insulation reaction 6 hours, treat that reaction finishes, close ammonia gas, cool down, crystallize, filter, dry to obtain 21.3g of 3-amino-2-nitrobenzoic acid, purity is 98.2%, yield The rate is 92.6%.

[0047] (2) Synthesis of 3-amino-2-nitrobenzoic acid methyl ester (3):

[0048]Add 50.0 g (0.273 mol) of 3-amino-2-nitrobenzoic acid and 800 mL of methanol into a 1000 mL four-neck flask, resulting in a yellow turbid system. Control the temperature at 20-30°C, add 40.3g (0.411mol) of concentrated sulfuric acid, raise the temperature to 70-75°C, stir for 4 hours, then cool down to below 5°C. Control the temperature T≤5°C, add sodium hydroxide to adjust the pH of ...

Embodiment 3

[0052]

[0053] (1) Synthesis of 3-amino-2-nitrobenzoic acid (2):

[0054] Add 150mL of purified water and 16.7g (0.124mol) of copper chloride to a 250mL four-necked bottle, then add 25g (0.124mol) of 3-chloro-2-nitrobenzoic acid, stir, and feed ammonia gas (flow rate 0.1ml Every minute), be warming up to 120 ℃, insulation reaction 6 hours, treat that reaction finishes, close ammonia gas, cool down, crystallize, filter, dry to obtain 21.3g of 3-amino-2-nitrobenzoic acid, purity is 97.2%, yield The rate is 91.6%.

[0055] (2) Synthesis of 3-amino-2-nitrobenzoic acid methyl ester (3):

[0056] Add 50.0 g (0.273 mol) of 3-amino-2-nitrobenzoic acid and 800 mL of methanol into a 1000 mL four-neck flask, resulting in a yellow turbid system. Control the temperature at 20-30°C, add 53.5g (0.546mol) of concentrated sulfuric acid, raise the temperature to 70-75°C, stir for 4 hours, then cool down to below 5°C. Control the temperature T≤5°C, add sodium hydroxide to adjust the pH of...

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Abstract

The invention discloses a preparation method of methyl 2, 3-diaminobenzoate, and belongs to the technical field of organic synthesis. 3-chloro-2-nitrobenzoic acid is used as a raw material, and the reaction route is as follows. According to the preparation method provided by the invention, the reaction is relatively mild, the product is easy to treat and purify and suitable for batch preparation, the synthetic route disclosed by the invention is short, and the used preparation method is simple and easy to operate and is a low-cost method suitable for batch preparation.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a preparation method of methyl 2,3-diaminobenzoate. Background technique [0002] Methyl 2,3-diaminobenzoate is a pharmaceutical intermediate that can be used to prepare methyl 2-ethoxy-4-carboxylate-3-hydro-benzimidazole, which in turn can be used to prepare trityl candesar Tan intermediates and other high value-added compounds have broad market prospects. Regarding methyl 2,3-diaminobenzoate, there are very few synthetic preparation methods reported in the literature at present, and the cost is high. [0003] Chinese patent application 200710049311.7 discloses a novel synthesis process of a trityl candesartan intermediate, the steps are as follows: (1) suspend 3-nitrophthalic acid in anhydrous methanol, then add chlorinated chlorinated Sulfone, heated and refluxed for 24 hours, concentrated to dryness, added petroleum ether to wash, and suction filtered ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C229/60C07C227/04
CPCC07C227/04C07C227/18C07C227/08C07C229/60Y02P20/55
Inventor 冉波张文灵钱刚王鹏刘国杰符含月
Owner HANGZHOU GUORUI BIO TECH CO LTD
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