Check patentability & draft patents in minutes with Patsnap Eureka AI!

Preparation method of p-acetoxystyrene and preparation method of its intermediate

A technology of acetoxystyrene and acetoxyacetophenone, which is applied in the field of preparation of p-acetoxystyrene, can solve the problems of high equipment requirements, industrialization is not feasible, and raw materials are not easy to obtain.

Inactive Publication Date: 2012-11-28
HENAN NEWLAND PHARMA
View PDF1 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the raw materials of these methods are not easy to obtain, the price of raw materials is high, and the reaction requires high equipment. Although 4-ASM can be obtained with considerable yield, industrialization is not feasible.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method of p-acetoxystyrene and preparation method of its intermediate
  • Preparation method of p-acetoxystyrene and preparation method of its intermediate
  • Preparation method of p-acetoxystyrene and preparation method of its intermediate

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0091] The invention discloses a preparation method of p-acetoxystyrene and a preparation method of an intermediate thereof. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to realize it. In particular, it should be pointed out that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and the relevant personnel can obviously make changes or appropriate changes and combinations to the method and application described herein without departing from the content, spirit and scope of the present invention to realize and Apply the technology of the present invention.

[0092] The reagents used in the preparation method of p-acetoxystyrene and the preparation method of its intermediate provided by the present invention ...

Embodiment 1

[0094] Embodiment 1 Preparation of p-acetoxystyrene

[0095] Accurately weigh 20 kg (0.15 mol) of p-hydroxyacetophenone and 15.3 kg (0.15 mol) of acetic anhydride for acetylation reaction, the reaction temperature is 180°C, and the reaction time is 2 hours. Distill under reduced pressure at a pressure of 0.1mmHg, collect fractions at 60-63°C, and obtain p-acetoxyacetophenone;

[0096] Accurately weigh 10kg of p-acetoxyacetophenone, melt it at 70°C, add 5 kg of hydrogenation solvent methanol (mass ratio: 1:0.5) A hydrogenation reaction occurs under catalysis, and distilled under a pressure of 0.1mmHg, and the fraction at 80-85°C is collected to obtain p-acetoxybenzylmethanol;

[0097] Accurately weigh 20 kg of p-acetoxybenzyl methanol in the presence of 0.02 kg of dehydrating agent hydrochloric acid (mass ratio 100:0.1), and 0.2 kg of polymerization inhibitor alkylhydroxybenzenesulfonic acid compounds (mass ratio 100: 1) , dehydrated at 145°C for 30h, collected 135°C fractio...

Embodiment 2

[0098] Embodiment 2 Preparation of p-acetoxystyrene

[0099] Accurately weigh 20 kg (0.15 mol) of p-hydroxyacetophenone and 153.14 kg (1.5 mol) of acetic anhydride for acetylation reaction, the reaction temperature is 80°C, and the reaction time is 30 h. Distill under reduced pressure at a pressure of 760mmHg, collect fractions at 326-330°C, and obtain p-acetoxyacetophenone;

[0100] Accurately weigh 10kg of p-acetoxyacetophenone, melt it at 50°C, add 300kg of hydrogenation solvent n-propanol (mass ratio: 1:30) A hydrogenation reaction occurs under catalysis, and after rectification under a pressure of 760mmHg, the fraction at 323-330°C is collected to obtain p-acetoxybenzylmethanol;

[0101] Accurately weigh 20 kg of p-acetoxybenzylmethanol in 0.02 kg of dehydrating agent hydrogen bromide (mass ratio 100: 0.1), 0.02 kg of polymerization inhibitor alkylhydroxybenzene sulfonic acid compounds, hydroxylamine compounds (mass ratio 100: 0.1) 0.1) Dehydration at 160°C for 2 hour...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to the chemical synthesis field, and especially relates to a preparation method of p-acetoxystyrene and a preparation method of its intermediate. The preparation method comprises the following steps: p-hydroxy acetophenone and acetic anhydride are subjected to an acetylation reaction to prepare p-acetoxyacetophenone, a hydrogenation solvent is added for dissolving, the p-acetoxyacetophenone is catalyzed with hydrogen under a catalyst to a hydrogenation reaction, purified to prepare p-acetoxy benzyl methanol, and a dehydration reaction is generated in the presence of a dehydrating agent and a polymerization inhibitor to prepare the p-acetoxystyrene. The test results show that the preparation method provided by the invention is characterized in that the esterification yield is 91.18%, the hydrogenation yield is 87.6%, the dehydration yield is 90.16%, the process total yield is 72.0%, the purity of the obtained p-acetoxystyrene is 99.5% and the synthesis amount is 50mol.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a preparation method of p-acetoxystyrene and a preparation method of an intermediate thereof. Background technique [0002] p-Acetoxystyrene (p-Acetoxystyrene), referred to as 4-ASM, CAS NO.: 2628-16-2, molecular weight: 162.19, molecular formula: C 10 h 10 o 2 , melting point: 8°C, boiling point: 260°C, appearance is colorless or light yellow liquid. Its structure is shown in formula I: [0003] [0004] Formula Ⅰ [0005] At present, p-acetoxystyrene is mainly synthesized by the following methods: [0006] Method 1: Synthesize 4-ASM from p-hydroxybenzaldehyde. [0007] Initially, Sovish started from p-hydroxybenzaldehyde and reacted with malonic acid to obtain p-hydroxystyrene through p-hydroxycinnamic acid. The yield of this method was only 41%. In 1982, International Flavors & Fragrances invented a method for preparing food-grade p-hydroxystyrene, which was also s...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C07C69/157C07C67/297C07C69/16C07C67/29
Inventor 谢建中郭秀彬刘超刘广正郝小龙
Owner HENAN NEWLAND PHARMA
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com