A kind of method of synthesizing 7-halogenated indoles

A technology of halogenated indole and halogenated aniline, which is applied in the field of synthesizing 7-halogenated indole, can solve the problems of high market price of 7-halogenated indole, high cost of raw materials, harsh reaction conditions, etc., and achieves low price, Good product purity and easy access to raw materials

Active Publication Date: 2019-01-04
CHANGZHOU XIAOGUO INFORMATION SERVICES
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But these methods all have certain defect, for example the reaction condition of Bischer method is harsher; Bartoli and Gassman method need very low temperature condition when preparing 7-halogenated indole; Reaction to produce 7-position unsubstituted indole
The methods reported at present often have high cost of raw materials, resulting in high market price of 7-halogenated indole

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] In a 100 mL four-necked flask with stirring, 25 mL of water, 15 mL (0.18 mol) of concentrated hydrochloric acid, and 10 g (0.090 mol) of o-fluoroaniline were successively added, and the reaction was stirred to obtain o-fluoroaniline hydrochloride for subsequent use. In another 500mL four-necked flask, add 140mL water and 71.6g (0.50mol) anhydrous sodium sulfate, stir and dissolve, add 16.5g (0.1mol) chloral hydrate, dropwise add the above o-fluoroaniline hydrochloride, and finally add 23g (0.33 mol) hydroxylamine hydrochloride. After the addition of materials, the mixture was stirred and heated to reflux for 10 minutes. After the reaction was completed, cooled to 0°C, filtered, washed, dried, and recrystallized from ethyl acetate to obtain 16.5 g (yield 97%) of yellow-brown solid powder N-(2-fluorophenyl)-2-isonitrosoacetyl aniline.

[0018] In a 250mL four-necked flask, 20g (0.11mol) of N-(2-fluorophenyl)-2-isonitrosoacetanilide was added to 100mL of concentrated sul...

Embodiment 2

[0021] In a 100 mL four-necked flask with stirring, 40 mL of water, 24 mL of concentrated hydrochloric acid (0.29 mol), and 3.06 g (0.024 mol) of o-chloroaniline were successively added to obtain o-chloroaniline hydrochloride for subsequent use. In another 500mL four-necked flask, add 60mL of water and 26.82g (0.19mol) of anhydrous sodium sulfate, stir and heat up to 35°C to dissolve, add 4.74g (0.029mol) of chloral hydrate, and dropwise add the above o-chloroaniline hydrochloride , and finally add 6.72 g (0.097 mol) of hydroxylamine hydrochloride. After the addition of materials, the mixture was stirred and heated to reflux for reaction, and the reaction time was 4 hours. After the reaction was completed, cooled to 0°C, filtered, washed, dried, and recrystallized from ethyl acetate to obtain 3.33 g (yield 70%) of yellow solid powder N-(2-chlorophenyl)-2-isonitrosoacetanilide .

[0022] In a 250mL four-necked flask, 5g (0.025mol) of N-(2-chlorophenyl)-2-isonitrosoacetanilide...

Embodiment 3

[0025] In a 100 mL four-necked flask with stirring, 20 mL of water, 3 mL of concentrated hydrochloric acid (0.036 mol), and 4.75 g (0.028 mol) of o-bromoaniline were successively added to obtain o-bromoaniline hydrochloride for subsequent use. In another 250mL four-necked flask, add 70mL of water and 35g (0.25mol) of anhydrous sodium sulfate, stir and heat up to 35°C to dissolve, add 5.01g (0.03mol) of chloral hydrate, dropwise add the above-mentioned o-bromoaniline hydrochloride, Finally, 6.10 g (0.088 mol) of hydroxylamine hydrochloride were added. After the addition was completed, the mixture was heated to 85°C with stirring for 3 hours (TLC monitoring). After the reaction was completed, it was cooled to 0° C., filtered, washed and dried to obtain 5.8 g (yield 85%) of N-(2-bromophenyl)-2-isonitrosoacetanilide as a yellow solid powder.

[0026] In a 250mL four-necked flask, add 25mL of concentrated sulfuric acid, heat up to 60°C and add 5g (0.021mol) N-(2-bromophenyl)-2-iso...

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PUM

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Abstract

The invention relates to a method for synthesizing 7-halogenoindoles.The method includes the steps that o-halogenated aniline, chloral hydrate and hydroxylamine hydrochloride are subjected to a Sandmeyer reaction to synthesize 7-halogenated indirubin; the 7-halogenated indirubin is dissolved through an organic solvent, the 7-halogenoindoles is obtained in a reduction reaction mode under the reducing agent condition, and the reducing agent is an alkali metal hydroboron system or a lithium aluminum hydride system or a lithium hydride system or a triethyl-silane system.The method has the advantages that the o-halogenated aniline, the chloral hydrate and the hydroxylamine hydrochloride serve as raw materials, and the 7-halogenated indirubin is prepared with the Sandmeyer isonitroso acetanilide synthesis method, and then is reduced through the reduction system to prepare 7-halogenoindoles; the method for preparing the 7-halogenoindoles from the 7-halogenated indirubin has the advantages that raw materials are easy to obtain, cost is low, the technology yield is high, the product purity is good, operation is easy and convenient, and the method is suitable for preparing the 7-halogenoindoles in a large-scale mode.

Description

technical field [0001] The present invention relates to a method for synthesizing 7-halogenated indole. Background technique [0002] 7-Haloindole is an important class of indole compounds. It has strong biological and pharmacological activities. Many natural or synthetic drugs and fine chemicals contain the structure of 7-haloindole. application prospects. There are many synthetic methods for these compounds, such as the classical Fischer method, Bischer method and Reissert method, the widely used Bartoli method, Gassman method and LB method. However, these methods have certain defects. For example, the reaction conditions of the Bischer method are harsh; the Bartoli and Gassman methods require extremely low temperature conditions for the preparation of 7-haloindole; the synthesis of 7-haloindole by the Fischer method is prone to abnormally heavy The row reaction produces the 7-position unsubstituted indole. The methods reported at present often have higher raw material ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D209/08
CPCC07D209/08
Inventor 刘长春程进刘承先蒋若愚徐进薛叙明周东东
Owner CHANGZHOU XIAOGUO INFORMATION SERVICES
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