Synthesizing process of 3-methyl-1 H-indazole

A synthesis process, the technology of indazole, which is applied in the field of synthesis process of indazole derivatives, can solve the problems of low yield, unfavorable large-scale synthesis and production of 3-methyl-1H-indazole, etc., and achieve simple steps and low cost , the effect of increasing the yield

Active Publication Date: 2015-12-30
上海泰坦科技股份有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] Although the above-mentioned prior art discloses a synthetic method of 3-methyl-1H-indazole, which can meet certain needs, but in the process of realizing the present invention, the inventor finds that there are still s

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  • Synthesizing process of 3-methyl-1 H-indazole

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Experimental program
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Embodiment 1

[0018] This embodiment relates to a synthesis process of 3-methyl-1H-indazole, which consists of the following steps:

[0019] Step 1: Synthesis of 2-nitroacetophenone

[0020] Slowly drop 100g of acetophenone into 500ml of sulfuric acid and nitric acid mixture (the volume ratio of concentrated sulfuric acid and concentrated nitric acid is 1:7, the temperature is -15°C), and then add 14g of 90 mesh calcium silicate powder (acetophenone and silicic acid The weight ratio of calcium powder is 1:0.14), kept stirring overnight below -15°C, then added to ice water, filtered to obtain 134g of yellow solid 2-nitroacetophenone, yield 97%, purity 99.8%, MS:m / z=165(M + ), elemental analysis: C58.1% (theoretical value 58.2%), H4.2% (theoretical value 4.2%), O29.0% (theoretical value 29.1%), N8.4% (theoretical value 8.5%), by Molecular weight and elemental analysis confirmed that it was 2-nitroacetophenone;

[0021] Step 2: Synthesis of 2-aminoacetophenone

[0022] Dissolve 110 g of t...

Embodiment 2

[0026] This embodiment relates to a synthesis process of 3-methyl-1H-indazole, which consists of the following steps:

[0027] Step 1: Synthesis of 2-nitroacetophenone

[0028] Slowly drop 100g of acetophenone into 500ml of sulfuric acid and nitric acid mixture (volume ratio of concentrated sulfuric acid and concentrated nitric acid is 1:7, temperature -15°C), and then add 23g of 80 mesh calcium silicate powder (acetophenone and silicic acid The weight ratio of calcium powder is 1:0.23), kept stirring overnight below -15°C, then added to ice water, filtered to obtain 131g of yellow solid 2-nitroacetophenone, yield 95%, purity 99.6%, MS:m / z=165(M + ), elemental analysis: C58.0% (theoretical value 58.2%), H4.2% (theoretical value 4.2%), O29.2% (theoretical value 29.1%), N8.4% (theoretical value 8.5%), by Molecular weight and elemental analysis confirmed that it was 2-nitroacetophenone;

[0029] Step 2: Synthesis of 2-aminoacetophenone

[0030] Dissolve 110 g of the above-me...

Embodiment 3

[0034] This embodiment relates to a synthesis process of 3-methyl-1H-indazole, which consists of the following steps:

[0035] Step 1: Synthesis of 2-nitroacetophenone

[0036] Slowly drop 100g of acetophenone into 500ml of sulfuric acid and nitric acid mixture (volume ratio of concentrated sulfuric acid and concentrated nitric acid is 1:7, temperature -15°C), then add 6g of 100 mesh calcium silicate powder (acetophenone and the The weight ratio of calcium silicate powder is 1:0.06), kept below -15°C and stirred overnight, then added to ice water, filtered to obtain 132g of yellow solid 2-nitroacetophenone, yield 96%, purity 99.7%, MS :m / z=165(M +), elemental analysis: C58.2% (theoretical value 58.2%), H4.1% (theoretical value 4.2%), O29.0% (theoretical value 29.1%), N8.4% (theoretical value 8.5%), by Molecular weight and elemental analysis confirmed that it was 2-nitroacetophenone;

[0037] Step 2: Synthesis of 2-aminoacetophenone

[0038] Dissolve 110 g of the above-ment...

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Abstract

The invention relates to a synthesizing process of 3-methyl-1 H-indazole. The synthesizing process comprises the following steps: acetophenone is dropped into a sulfuric acid and nitric acid mixture solution, then calcium metasilicate powder is added, the mixture is kept to be stirred at lower temperature and passes through the night, the mixture is added into ice water and filtered, and 2-nitroacetophenone is obtained; the 2-nitroacetophenone, iron powder and ammonium chloride are synthesized into white solid 2-aminoacetophenone; the 2-aminoacetophenone is added to hydrochloric acid, then an NaNO2 aqueous solution is added, the mixture is stirred, then a hydrochloric acid solution of SnCl2.H2O is added, the mixture is stirred, the mixture is added to ice water and filtered, and filtrate is adjusted to alkalescence, filtered and dried so that the 3-methyl-1 H-indazole is obtained. According to the synthesizing process of the 3-methyl-1 H-indazole, calcium silicate is taken as a catalyst, the yield of the 2-nitroacetophenone is increased remarkably, the raw material of calcium silicate is easy to obtain, the cost is low, the operation and the use are simple, later synthesis of 2-aminoacetophenone and the 3-methyl-1 H-indazole is further facilitated, and the synthesizing process is suitable for industrial large-scale synthesis of 3-methyl-1 H-indazole.

Description

technical field [0001] The invention relates to a synthesis process of indazole derivatives, in particular to a synthesis process of 3-methyl-1H-indazole. Background technique [0002] Indazole is an important intermediate in organic synthesis. Many indazole compounds have antidepressant, anti-inflammatory, analgesic and antipyretic, dopamine antagonism, anti-tumor, anti-HIV and contraceptive drug activities, and are also widely used in pesticides. Because of the important physiological activity and potential medicinal value of indazole derivatives, such as 3-methyl-1H-indazole, it is of great significance and application value to study their synthetic methods. [0003] CN102898374A (published on January 30, 2013) discloses a method for obtaining 3-methyl-1H-indazole without reflux heating reaction of hydrazine hydrate and without purification of the product through a column. The method includes The following steps: Step 1, 2-amino-5-R-acetophenone as a raw material or inte...

Claims

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Application Information

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IPC IPC(8): C07D231/56
CPCC07D231/56
Inventor 谢应波张庆张华徐肖冰罗桂云
Owner 上海泰坦科技股份有限公司
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