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Process for preparing N-alkyl-3,4-(methylene dioxy) aniline through reduction-alkylation of 3,4-( methylene dioxy) nitrobenzene

A technology of methylene dioxygen and alkyl arylamine, which is used in the preparation of dye intermediates and in the field of medicine, can solve the problems of expensive catalysts and unsatisfactory yields, and achieve the effects of easy treatment, less three wastes and low prices.

Inactive Publication Date: 2005-12-28
DALIAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The catalyst is expensive and the yield is not ideal

Method used

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  • Process for preparing N-alkyl-3,4-(methylene dioxy) aniline through reduction-alkylation of 3,4-( methylene dioxy) nitrobenzene
  • Process for preparing N-alkyl-3,4-(methylene dioxy) aniline through reduction-alkylation of 3,4-( methylene dioxy) nitrobenzene

Examples

Experimental program
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Effect test

Embodiment 1

[0018] 20 grams of 3,4-(methylenedioxy)-nitrobenzene, 160 grams of toluene, 2 grams of skeleton nickel, and a toluene solution containing 13 grams of acetaldehyde were added to the autoclave, under 1.6 MPa hydrogen pressure, at 80 After passing hydrogen for 3 hours at ℃, under 1.6MPa hydrogen pressure, react with hydrogen at 60°C for 8 hours. The product is analyzed by high-pressure liquid chromatography. Except for toluene, the contents of each component are: N-ethyl-3,4-(methylenedioxy)aniline 96%, 3,4-(methylenedioxy)aniline 0.3%, N,N-diethyl-3,4-(methylenedioxy)aniline and other by-products were 3.7%, and 3,4-(methylenedioxy)-nitrobenzene was not detected.

Embodiment 2

[0020] 20 grams of 3,4-(methylenedioxy)-nitrobenzene, 160 grams of toluene, 3 grams of skeleton nickel, and an ethanol solution containing 13 grams of acetaldehyde were added to the autoclave, under 1.2 MPa hydrogen pressure, at 60 After passing hydrogen at ℃ for 4 hours, under a hydrogen pressure of 1.2 MPa, conduct hydrogen reaction at 60°C for 10 hours. The product is analyzed by high-pressure liquid chromatography, and the contents of each component are: N-ethyl-3,4-(methylenedioxy)aniline 94.5%, 3,4-(methylenedioxy)aniline 0.9%, N,N -Diethyl-3,4-(methylenedioxy)aniline and other by-products 4.6%, 3,4-(methylenedioxy)-nitrobenzene was not detected.

Embodiment 3

[0022] Add 20 grams of 3,4-(methylenedioxy)-nitrobenzene, 160 grams of toluene, 2 grams of skeleton nickel, and 10 parts of acetone into the autoclave, and react with hydrogen at 60°C under a hydrogen pressure of 1.0 MPa for 5 After 1 hour, under 1.MPa hydrogen pressure, react with hydrogen at 60°C for 8 hours. The product is analyzed by high-pressure liquid chromatography. Except toluene, the contents of each component are: N-isopropyl-3,4-(methylenedioxy)aniline 96.7%, 3,4-(methylenedioxy)aniline 0.4% , other by-products 2.9%, 3,4-(methylenedioxy)-nitrobenzene was not detected.

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Abstract

The present invention takes 3,4-(methylenedioxy)-nitrobenzene as starting material, C 1 -C 4 The low-level aliphatic aldehyde / ketone is used as the alkylating agent, and the skeleton nickel is used as the catalyst, and the hydrogenation reduction and alkylation reaction are continuously carried out in one pot method to directly prepare N-alkyl-3,4 (methylenedioxy)aniline. Process: ∴ R = H or C 1 -C 3 alkyl. The method has the characteristics of high conversion rate and yield, good selectivity of monoalkylation, applicable catalyst, less "three wastes" and easy treatment.

Description

technical field [0001] The invention belongs to the preparation method of medicine and dye intermediates. Background technique [0002] There are generally two synthetic methods of N-alkyl-3,4-(methylenedioxy)aniline (also known as N-alkyl-1,3-dioxa-benzocyclopentene): one is based on 1,2-(methylenedioxy)benzene is produced by bromination and alkylammonolysis; the other is produced by 3,4-(methylenedioxy)-nitrobenzene by reduction and alkylation. [0003] European Patent EP 0549263 has reported the method for preparing N-alkyl-3,4-(methylenedioxy)aniline with 1,2-(methylenedioxy)benzene through bromination and alkane aminolysis. Make solvent with a large amount of glacial acetic acid and methyl alcohol, brominate with 48% hydrobromic acid and 30% hydrogen peroxide, this process solvent recovery difficulty and produce a large amount of waste water, the intermediate product 3,4-(methylenedioxy) bromobenzene The storage stability is poor; the separation of the organic ammoniu...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D317/50
Inventor 吴祖望冯柏成吴作林韩德彰董振堂林莉
Owner DALIAN UNIV OF TECH