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Method for preparing 1-chloro-2-methyl-4-alkylacyloxy-2-butene

一种烃酰氧基、甲基的技术，应用在药物化学领域，能够解决产物收率和含量差、杂质增多、产品含量差等问题，达到反应体系温和、含量和收率高、杂离子少的效果

Active Publication Date: 2006-10-11
SHAOXING UNIVERSITY +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, after experimental verification, it was found that the yield and content of the product were very poor during the chlorohydrination reaction
[0011] Usually the chloroalcoholation reaction of olefin can lead chlorine in calcium hydroxide aqueous suspension, utilize the active hypochlorous acid of generation to directly carry out chlorohydrinization ((Encyclopedia of Chemical Engineering) editorial committee, Encyclopedia of Chemical Industry, Chemical Industry Press, 1996 the first 1st edition, Vol.16, P719-729); But the inventor finds that the product content of this method is very poor after the experiment, may be that the existence of free chlorine gas and other miscellaneous ions makes the double bond of alkene have dichlorination addition etc. Side reactions, resulting in increased impurities

Method used

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  • Method for preparing 1-chloro-2-methyl-4-alkylacyloxy-2-butene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Example 1: Preparation of 1-chloro-2-hydroxyl-2-methyl-3-butene and 1-chloro-2-methyl-4-hydroxyl-2-butene mixture

[0040] Put a 500ml three-necked bottle equipped with a thermometer and a solid feeding port into an alcohol cooling bath; add 68g (1mol) of isoprene, 100ml of water and 0.5g of inhibitor hydroquinone; Control the temperature at the feeding port and add trichloroisocyanuric acid (90% available chlorine) in batches, a total of 58g (0.25mol), and add it in about 1 hour, then continue to keep warm and stir for 1 hour, filter, wash the filter cake with 15ml of water, and it is a loose white powder Solid, weighing 31 g (0.24 mol) after drying. The filtrates were combined and allowed to stand for separation. The organic layer was lower than 40°C to recover unreacted isoprene under reduced pressure to obtain 90 g of crude product. Gas phase analysis showed that the total content of the product was 92.5%, and the yield was 92.1%. It can be directly used in the nex...

Embodiment 2

[0041] Example 2: Preparation of 1-chloro-2-methyl-4-acetoxy 2-butene by esterification rearrangement reaction

[0042] In a 250ml three-necked flask, add 63g of the crude product (content 92.5%, 0.48mol) and 80g (0.78mol) of acetic anhydride, stir and add 1g of p-toluenesulfonic acid, heat up to 60°C and stir for 5 hours, cool to room temperature, add 100ml water layer, discard the upper waste water, the lower organic layer is washed with 100ml water and then stratified to obtain 63g (content 90%) of crude product chloride, after rectification (80-90°C / 1mmHg), 55g colorless transparent liquid (content 93.5%), yield 66%. GC-MS (m / e): 127, 102, 84, 67, 43 (100%), 29; IR (ν / cm -1 ): 1735 (-OCO-, carbonyl); 1230 (-C-O-CO-, ν as ), 1035 (-C-O-CO-, ν s ); 1 HNMR (500MHz, CDCl 3 )δ (ppm): 1.83 (s, 3H, -CH 3 ); 2.06(s,3H,-COCH 3 ); 4.01 (2H, Cl-CH 2 -); 4.62 (2H, =CH 2 ); 5.69 (1H, -CH=); DEPT: δ (ppm): 124.019 (1H, =CH-); 62.535 (2H, -OCH 2 -); 50.135 (2H, -CH 2 -Cl); 21....

Embodiment 3

[0043] Embodiment 3: material proportioning, operating temperature and aftertreatment are the same as embodiment 1, the difference is that the water for reaction is the waste water layer in embodiment 1. 93g of crude product was obtained, gas phase analysis showed that the total product content was 89.5%, and the yield was 92.1%. The filter cake is a loose white powder solid, weighing 30.5 grams (0.236 mol) after drying, and the water layer is 98 grams.

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Abstract

The method provides a Method for preparation of vitaminA derivant's important intermediate- 1-chloro-2-methyl-4-hydrocarbon acyloxy-2-butylene, this invention adopting isoprene as material to carry through chlorohydrination reaction; the getted product has high content, high produce rate, convenierce operate, little waste and easy to commercial manufacture.

Description

Technical field: [0001] The invention belongs to the technical field of medicinal chemistry. It specifically relates to a synthesis method of 1-chloro-2-methyl-4-alkanoyloxy-2-butene, an important intermediate of vitamin A carboxylate. Background technique [0002] Vitamin A (V A ) and its derivatives are an important class of drugs, where V A Carboxylate derivatives such as V A Acetate and palmitate are widely used in drugs, food additives and feed additives; the products of major companies in the world are marked with V A Carboxylic acid esters are mainly ((Encyclopedia of Chemical Engineering) Editorial Committee, Encyclopedia of Chemical Engineering, Chemical Industry Press, first edition in 1996, Vol.16, P719-729). 4-hydrocarbonyloxy-2-methyl-2-buten-1-aldehyde (hereinafter referred to as five-carbon aldehyde, where R 1 is a hydrocarbon group) is a C characterized by a Wittig reaction 15 +C 5 Route Synthesis V A The key intermediate (Tanaka, USP 5,424,478, Proce...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/14C07C69/52
CPCC07C67/293C07C67/14C07C67/08C07C29/66C07C33/423C07C69/007C07C69/63
Inventor 沈润溥虞国棋叶伟东王奎劳学军
Owner SHAOXING UNIVERSITY
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