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Preparation method of 2,5-diaminophenethyl alcohol sulfate

A technology of diaminobenzene and nitrophenylethanol, which is applied in the field of hair dye preparation, can solve the problems of high cost and low yield, and achieve simple operation, high reaction yield, great implementation value and social effects

Inactive Publication Date: 2013-08-14
ZHEJIANG UNIV OF TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0023] The present invention provides a low-cost, high-yield, and easy-to-operate 2,5-diamino The preparation method of phenylethyl alcohol sulfate

Method used

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  • Preparation method of 2,5-diaminophenethyl alcohol sulfate
  • Preparation method of 2,5-diaminophenethyl alcohol sulfate
  • Preparation method of 2,5-diaminophenethyl alcohol sulfate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0052] (1) Synthesis of 2-chloro-5-nitrophenylacetic acid

[0053] In a 1L four-neck flask, mix o-chlorophenylacetic acid (200g, 1.2mol) and concentrated sulfuric acid (800g, 8.2mol H 2 SO 4 ) mix, stir and cool down to -10°C, add dropwise concentrated nitric acid (80g, 1.3mol HNO 3 ), dripping is completed, stirred and kept at -10°C for 12 hours, after sampling and analyzing no raw materials, pour it into a large amount of ice water (1000g), filter with suction, wash the filter cake with ice water and dry it in vacuum at 0.1MPa for 12 hours to obtain 5 -Nitro-2-chlorophenylacetic acid 215g, HPLC content 99.1%, productive rate 85%.

[0054] HPLC detection condition is:

[0055] Mobile phase: acetonitrile: water: triethylamine = 200: 300: 0.3ml

[0056] Chromatographic column: C184.6×150mm Wavelength: 210nm Flow rate 1.2ml / min.

[0057] (2) Synthesis of 2-chloro-5-nitrophenylethanol

[0058] Add sodium borohydride (87g, 2.3mol) and toluene (1kg) into a four-necked reactio...

Embodiment 2

[0064] (1) Synthesis of 2-chloro-5-nitrophenylacetic acid

[0065] In a 1L four-neck flask, mix o-chlorophenylacetic acid (200g, 1.2mol) and concentrated sulfuric acid (1600g, 16.4molH 2 SO 4 ) mix, stir at room temperature (25°C), add dropwise concentrated nitric acid (80g, 1.3mol HNO 3), dripping, heat preservation reaction for 2 hours, after sampling and analysis without raw materials, pour the reaction solution into a large amount of ice water (1000g), filter with suction, take the filter cake and wash it with ice water and then vacuum dry it under 0.1MPa for 12h to obtain 5 -Nitro-2-chlorophenylacetic acid 203g, HPLC content 97.5%, productive rate 80%.

[0066] (2) Synthesis of 2-chloro-5-nitrophenylethanol

[0067] Add 38g (1.0mol) sodium borohydride and 1kg tetrahydrofuran into a four-necked reaction flask and stir to dissolve, cool down to 0°C, add 200g (0.9mol) 2-chloro-5-nitrophenylacetic acid, slowly dropwise add 365.1g (3.6 mol HCl) 200g of tetrahydrofuran solu...

Embodiment 3

[0073] (1) Synthesis of 2-chloro-5-nitrophenylacetic acid

[0074] In a 1L four-neck flask, mix o-chlorophenylacetic acid (200g, 1.2mol) and concentrated sulfuric acid (1104g, 11.3mol H 2 SO 4 ) mix, stir and cool down to 0°C, control the temperature from 0 to 5°C, add dropwise concentrated nitric acid with a mass concentration of 65% (170g, 1.8mol HNO 3 ), dripping is completed, stirred and kept at 0°C for 6 hours, after sampling and analyzing no raw materials, pour it into a large amount of ice water (1000g), filter with suction, take the filter cake and wash it with ice water, and then dry it in vacuum at 0.1MPa for 12 hours to obtain 5 -Nitro-2-chlorophenylacetic acid 233g, HPLC content 99.3%, productive rate 92%.

[0075] (2) Synthesis of 2-chloro-5-nitrophenylethanol

[0076] Add 68g (1.8mol) of sodium borohydride and 1kg of tetrahydrofuran into a four-necked reaction flask and stir to dissolve, lower the temperature to 0°C, add 200g (0.9mol) of 2-chloro-5-nitrophenyl...

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Abstract

The invention discloses a preparation method of 2,5-diaminophenethyl alcohol sulfate. The preparation method comprises the following steps of: carrying out mixed acid nitration to obtain 2-chlorine-5- nitrobenzene alcohol based on o-clorophenylacetic acid as a raw material; reducing carboxyl of 2-chlorine-5-nitrobenzene alcohol with sodium borohydride under an acidic condition to obtain 2-chlorine-5-nitrobenzene alcohol; carrying out high-pressure ammoniation on the 2-chlorine-5-nitrobenzene alcohol under high pressure with stronger ammonia water to obtain 2-amino-5-nitrobenzene alcohol; and reducing by using a hydrogenation catalyst and salifying with concentrated sulfuric acid in one step to obtain the 2,5-diaminophenethyl alcohol sulfate. The preparation method of the 2,5-diaminophenethyl alcohol sulfate is reasonable in process route, shorter in reaction steps, cheap and easily available in material, higher in reaction yield, lower in material cost, simple to operate and easy to produce on large scale.

Description

(1) Technical field [0001] The invention relates to a preparation method of a hair dye, in particular to a preparation method of 2,5-diaminophenethyl sulfate. (2) Background technology [0002] Hair dye 2,5-diaminophenethyl alcohol sulfate, CAS number: 93841-25-9, the structure is shown in formula (I): [0003] [0004] At room temperature, 2,5-diaminophenylethanol is a yellow solid, easily oxidized, and generally exists in the form of hydrochloride or sulfate, and its hydrochloride or sulfate is a white solid. 2,5-Diaminophenylethanol and its salts are widely used in dyes, pigments, pesticides and polymers, and are mainly used as a highly efficient oxidative hair dye. [0005] 2,5-diaminophenylethanol and its salts are mainly used as a high-efficiency oxidative hair dye, which is expensive, and there are few reports on its synthesis literature, and various 2,5-diaminophenylethanol synthetic methods reported in domestic and foreign literature , according to the differen...

Claims

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Application Information

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IPC IPC(8): C07C215/68C07C213/02C07C213/08
Inventor 钟为慧王冠蔡继平苏为科
Owner ZHEJIANG UNIV OF TECH