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Method for synthesizing 5-bromo-4-fluoro-1H-indazole

A synthesis method and indazole technology, applied in the field of 5-bromo-4-fluoro-1H-indazole and its synthesis, can solve the problems of less reports, achieve high product yield, short synthesis route, and mild reaction conditions Effect

Inactive Publication Date: 2019-11-15
NANTONG UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] At present, there are few reports about the synthetic methods of such compounds or their derivatives

Method used

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  • Method for synthesizing 5-bromo-4-fluoro-1H-indazole
  • Method for synthesizing 5-bromo-4-fluoro-1H-indazole
  • Method for synthesizing 5-bromo-4-fluoro-1H-indazole

Examples

Experimental program
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Effect test

Embodiment 1

[0020] (a) Synthesis of 4-bromo-3-fluoro-2-methylaniline (compound 2):

[0021] In a 3L four-necked flask, 50g of 3-fluoro-2-methylaniline (compound 1) was dissolved in 0.75L of acetonitrile, the temperature was controlled below 10°C, and 78.3g of N-bromosuccinyl was added in batches imine. The temperature was controlled at -10°C for 1 h. Thin layer chromatography analysis raw material reaction is complete, add 50g sodium bisulfite, continue to react for 10min with stirring, add sodium hydroxide to adjust pH to be 9, extract with ethyl acetate (2 * 1L), dry organic phase with anhydrous sodium sulfate, concentrate to Dry, pour 500mL cyclohexane to remove impurities. After filtering, the filter cake was rinsed with 500 mL of cyclohexane to obtain 79 g of 4-bromo-3-fluoro-2-methylaniline (compound 2), with a yield of 96.8%.

[0022] (b) Synthesis of 1-(5-bromo-4-fluoro-1H-indazol-1-yl)ethanone (compound 3):

[0023] In a 1L four-neck flask, dissolve 20.4g of 4-bromo-3-fluoro-...

Embodiment 2

[0028] (a) Synthesis of 4-bromo-3-fluoro-2-methylaniline:

[0029] Add 50g of 3-fluoro-2-methylaniline and dissolve it in 0.75L of acetonitrile in a 3L four-neck flask, control the temperature below 10°C, and add 78.3g of N-bromosuccinimide in batches. Control the temperature below 10°C for 2 hours. According to thin-layer chromatography, the reaction of the raw materials was complete. Add 50 g of sodium bisulfite, continue to stir for 10 min, add sodium hydroxide to adjust the pH to 9-10, extract with ethyl acetate (2×1 L), dry the organic phase over anhydrous sodium sulfate, and concentrate To dryness, pour 500mL cyclohexane to remove impurities. After filtering, the filter cake was rinsed with 500 mL of cyclohexane to obtain 70.3 g of 4-bromo-3-fluoro-2-methylaniline, with a yield of 86.2%.

[0030] (b) Synthesis of 1-(5-bromo-4-fluoro-1H-indazol-1-yl)ethanone:

[0031] In a 1L four-necked flask, 20.4g of 4-bromo-3-fluoro-2-methylaniline was dissolved in 200mL of toluene...

Embodiment 3

[0035] (a) Synthesis of 4-bromo-3-fluoro-2-methylaniline:

[0036] Add 50g of 3-fluoro-2-methylaniline and dissolve it in 0.75L of acetonitrile in a 3L four-neck flask, control the temperature below 10°C, and add 78.3g of N-bromosuccinimide in batches. Control the temperature below 10°C for 2 hours. According to thin-layer chromatography, the reaction of the raw materials was complete. Add 50 g of sodium bisulfite, continue stirring for 30 min, add sodium hydroxide to adjust the pH to 9-10, extract with ethyl acetate (2×1 L), dry the organic phase over anhydrous sodium sulfate, and concentrate To dryness, pour 500mL cyclohexane to remove impurities. After filtering, the filter cake was washed with 500 mL of cyclohexane to obtain 80 g of 4-bromo-3-fluoro-2-methylaniline with a yield of 98%.

[0037] (b) Synthesis of 1-(5-bromo-4-fluoro-1H-indazol-1-yl)ethanone:

[0038] In a 1L four-necked flask, 20.4g of 4-bromo-3-fluoro-2-methylaniline was dissolved in 200mL of toluene, th...

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Abstract

The invention belongs to the field of organic synthesis, and discloses a method for synthesizing 5-bromo-4-fluoro-1H-indazole. The synthesis method comprises the steps: adopting 3-fluoro-2-methylaniline as a raw material, and performing three steps of reactions including a bromination reaction, a ring closing reaction and a deprotection reaction so as to synthesize the 5-bromo-4-fluoro-1H-indazole. The reaction conditions are mild, the synthesis method is simple, the synthesis route is short, the product yield is high, and the method is suitable for large-scale industrial production.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to 5-bromo-4-fluoro-1H-indazole and a synthesis method thereof. Background technique [0002] Indazole compounds or their physiologically acceptable derivatives respectively have the effect of inhibiting Rho kinase activity; have the effect of relaxing blood vessels and protecting blood vessel function; have the effect of protecting myocardial cells against hypoxia-reperfusion injury; and have the effect of promoting cell glucose consumption. It has the function of protecting vascular endothelial cells against oxidative damage. It is a kind of cardiovascular and cerebrovascular diseases, New compounds with important uses in medicines such as diabetes. [0003] At present, there are few reports about the synthesis methods of such compounds or their derivatives. Therefore, it is of great significance how to obtain an indazole compound with mild reaction conditions and su...

Claims

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Application Information

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IPC IPC(8): C07D231/56
CPCC07D231/56
Inventor 朱金丽陆麟霞田丹苏广军金瑞娣尤克菲陈娇魏莹莹王春现
Owner NANTONG UNIVERSITY
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