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Preparation method of 1-chlorin -2-methyl -4-acetoxy-2- butylene

A technology of acetoxy and methyl, which is applied in the chemical field, can solve the problems of increased impurities and poor product content, and achieve the effects of convenient storage and transportation, less miscellaneous ions, and a mild reaction system

Inactive Publication Date: 2007-09-26
ZHEJIANG MEDICINE CO LTD XINCHANG PHAMACEUTICAL FACTORY +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] Usually the chloroalcoholation reaction of olefins can pass chlorine gas in the calcium hydroxide aqueous suspension, and 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, the first in 1996 Edition, Vol.16, P719-729); but we found that the content of the product was very poor after experimental verification, which may be due to the presence of free chlorine and other miscellaneous ions that caused the double bond of olefins to undergo side reactions such as dichloro addition , resulting in an increase in impurities

Method used

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  • Preparation method of 1-chlorin -2-methyl -4-acetoxy-2- butylene
  • Preparation method of 1-chlorin -2-methyl -4-acetoxy-2- butylene
  • Preparation method of 1-chlorin -2-methyl -4-acetoxy-2- butylene

Examples

Experimental program
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Effect test

Embodiment 1

[0022] Example 1: Preparation of 1-chloro-2-hydroxyl-2-methyl-3-butene and 1-chloro-2-methyl-4-hydroxyl-2-butene mixture

[0023] Put the 1000ml four-neck bottle equipped with a thermometer, a solid feeding port and a dropping funnel into an alcohol cooling bath; add 68g (1mol) isoprene, 100ml water and 0.1g inhibitor hydroquinone; Put 150g of 50% acetic acid aqueous solution in the funnel, stir and add the acetic acid aqueous solution dropwise at 0-5°C, while adding slowly, add bleaching powder (30% available chlorine) in batches from another feeding port, totaling 150g, and continuously measure the pH value , keep the pH value between 7.5 and 8.5 (test paper or pH meter can be used), after about three hours, the dropwise addition is completed, then continue to insulate and stir for 1 hour, filter, wash the filter cake with dichloromethane, and leave the filtrates to separate after merging. After the organic layer was washed with water, 118 g of the crude product was recovere...

Embodiment 2

[0024] Example 2: Preparation of 1-chloro-2-hydroxyl-2-methyl-3-butene and 1-chloro-2-methyl-4-hydroxyl-2-butene mixture

[0025] Ratio of materials, operating temperature and aftertreatment are the same as in Example 1, the difference is that 50% acetic acid aqueous solution is disposablely added in the reaction flask, bleaching powder (30% available chlorine) is added in batches, and the pH value of the system is constantly changing, from the beginning The 3 or so becomes between 7.5 and 8 at the end. 103 g of crude product was obtained, gas phase analysis showed that the total product content was 86.5%, and the yield was 74%.

Embodiment 3

[0026] Example 3: Preparation of 1-chloro-2-methyl-4-acetoxy-2-butene by esterification rearrangement reaction

[0027] In a 250ml three-necked flask, add 64g (content 90.5%, 0.48mol) of the crude product obtained in Example 1 and 80g (0.78mol) of acetic anhydride, stir and add 1g p-toluenesulfonic acid, heat up to 60°C and stir for 5 hours, then cool down. Add 100ml of water to separate the layers, discard the upper waste water, add 100ml of water to the lower organic layer and wash with water to obtain 63g (content 90%) of crude product chloride. %. 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); 21.106 (3H, -CH 3 ); 14.807 (3H, -CH 3 ).

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Abstract

The invention discloses a making method of 1-chlorine-2-methyl-4-acetoxy-2-butene, which comprises the following steps: adopting isoprene as raw material; adding calcium hypochlorite solid and acetic acid as pH value adjuster to do chlorohydrin reaction; obtaining the additional product of 1, 2 position and 1, 4 position; reacting the additional product and acetic anhydride catalyzed by acid to produce the product; making the reacting system mild with little heteroion; improving the content and receiving rate of product.

Description

technical field [0001] The invention relates to the field of chemistry, in particular to the synthesis of V A Preparation method of important intermediate 1-chloro-2-methyl-4-acetoxy-2-butene of acetate. Background technique [0002] Vitamin A (V A ) and its derivatives are an important class of drugs, and the products of major companies in the world are marked with V A Acetate-based ((Encyclopedia of Chemical Engineering) Editorial Committee, Encyclopedia of Chemical Engineering, Chemical Industry Press, first edition in 1996, Vol.16, P719-729). 4-Acetoxy-2-methyl-2-buten-1-aldehyde (MW142, referred to as five-carbon aldehyde) is a C characterized by Wittig reaction 15 +C 5 Route Synthesis V A Key intermediate of acetate (Tanaka, USP 5,424,478, Process for producing Vitamin A Derivatives, [P] 1995; Tanaka, et al., JP 06,329,623, Preparation of Vitamin A Derivatives, [P] 1994; Zutter, Ulrich , Ep 648,735, Preparation of an intermediate f...

Claims

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Application Information

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IPC IPC(8): C07C67/08C07C69/145
Inventor 叶伟东沈润溥徐国兴虞国棋
Owner ZHEJIANG MEDICINE CO LTD XINCHANG PHAMACEUTICAL FACTORY
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