Method for synthesizing 7-halogenoindoles

A halogenated indole and halogenated aniline technology, which is applied in the field of synthesizing 7-halogenated indole, can solve the problems of harsh reaction conditions, high raw material cost and high market price of 7-halogenated indole, and achieves easy availability of raw materials, The effect of good product purity and low price

Active Publication Date: 2016-07-06
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-halo

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] In a stirred 100mL four-neck flask, add 25mL of water, 15mL (0.18mol) of concentrated hydrochloric acid, and 10g (0.090mol) of o-fluoroaniline in sequence, and stir to prepare o-fluoroaniline hydrochloride for later use. Add 140mL of water and 71.6g (0.50mol) of anhydrous sodium sulfate into another 500mL four-neck flask, stir and dissolve, add 16.5g (0.1mol) of chloral hydrate, add the above-mentioned o-fluoroaniline hydrochloride dropwise, and finally add 23g (0.33 mol) hydroxylamine hydrochloride. After the addition, the reaction was stirred and heated under 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 tan solid powder N-(2-fluorophenyl)-2-isonitrosoacetyl aniline.

[0018] In a 250mL four-neck flask, add 20g (0.11mol) of N-(2-fluorophenyl)-2-isonitrosoacetanilide in batches to 100mL of concentrated sulfuric acid, the temperature during the addi...

Embodiment 2

[0021] In a 100 mL four-neck flask with stirring, add 40 mL of water, 24 mL of concentrated hydrochloric acid (0.29 mol), and 3.06 g (0.024 mol) of o-chloroaniline in sequence to prepare o-chloroaniline hydrochloride for later use. Add 60mL of water and 26.82g (0.19mol) of anhydrous sodium sulfate to another 500mL four-neck flask, stir and heat up to 35°C to dissolve, add 4.74g (0.029mol) of chloral hydrate, and dropwise add the above-mentioned o-chloroaniline hydrochloride , and finally added 6.72 g (0.097 mol) of hydroxylamine hydrochloride. After the addition, the mixture was stirred and heated to reflux for a reaction time of 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-neck flask, add 5g (0.025mol) of N-(2-chlorophenyl)-2-isonitrosoacetanilide in batches to 15mL of concentrat...

Embodiment 3

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

[0026] In a 250mL four-neck flask, add 25mL of concentrated sulfuric acid, raise the temperature to 60°C and add 5g (0.021mol) of N-(2-bromophenyl)-2-isonitrosoacet...

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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 invention relates to a method for synthesizing 7-halogenated indoles. Background technique [0002] 7-halogenated indole 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-halogenated indole, which has a broad range of applications. Application prospect. There are many synthetic methods of such compounds, such as the classic Fischer method, Bischer method and Reissert method, and the widely used Bartoli method, Gassman method and LB method. 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; Elimination reaction to generate 7-position unsubstituted indole. The currently reported methods often have high cost of raw materials, resulting in high market prices of 7-haloge...

Claims

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Application Information

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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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