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Prepn process of 9,10-dibromo-9,10-dihydro-4H-benzo-[4,5]-suberene-[1,2-b]-thienyl-4-one

A technology of cycloheptene and dihydro, applied in 9,10-dibromo-9,10-dihydro-4-Hbenzo[4,5]cyclohepteno[1,2-b]thiophene- In the field of 4-ketone preparation, it can solve the problems of reduced product yield, difficult separation, and large proportion of impurities, and achieve the effects of reducing the generation of by-products, overcoming low yield and strong selectivity

Active Publication Date: 2006-10-18
ZHEJIANG HUAHAI PHARMACEUTICAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Because the solubility of dibromide [such as formula (I)] is also quite large in carbon tetrachloride, after it is generated in the reaction, it also continues to generate more bromine-substituted by-products with the bromination agent effect, and these impurities form a ratio Larger, when preparing ketotifen, it is very difficult to separate
Complicated separation methods are often required, resulting in lower product yields and higher costs

Method used

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  • Prepn process of 9,10-dibromo-9,10-dihydro-4H-benzo-[4,5]-suberene-[1,2-b]-thienyl-4-one
  • Prepn process of 9,10-dibromo-9,10-dihydro-4H-benzo-[4,5]-suberene-[1,2-b]-thienyl-4-one
  • Prepn process of 9,10-dibromo-9,10-dihydro-4H-benzo-[4,5]-suberene-[1,2-b]-thienyl-4-one

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] 50g 9,10-dihydro-4-H benzo[4,5]cyclohepteno[1,2-b]thiophen-4-one was dissolved in 1000ml cyclohexane, 70g dibromohydantoin was added, 1.5 g BPO, heated to 70°C, stirred for 8 hours, cooled to room temperature, filtered, added 1000ml of chloroform to the filter cake, washed with 600ml of water, separated into layers, concentrated the organic layer to dryness under reduced pressure, and collected 62g of the dried dibromide. Melting point: 133-136°C. Yield: 71.3%.

Embodiment 2

[0033] Dissolve 50g of 9,10-dihydro-4-Hbenzo[4,5]cyclohepteno[1,2-b]thiophen-4-one in 1000ml cyclohexane, add 90g NBS, 1.5g BPO, Heat the temperature to 70°C, stir for 8 hours, cool to room temperature, filter, add 1000ml of chloroform to the filter cake, wash with 600ml of water, separate layers, and concentrate the organic layer to dryness under reduced pressure to obtain 60.2g of dibromide. Yield: 69.2%, melting point: 130-133.5°C.

Embodiment 3

[0035] Dissolve 50g of 9,10-dihydro-4-Hbenzo[4,5]cyclohepteno[1,2-b]thiophen-4-one in 1000ml of n-heptane, add 70g of dibromohydantoin, 1g BPO, heated to 70°C, stirred for 8 hours, cooled to room temperature, filtered, the filter cake was washed with 1000ml chloroform and 600ml water, separated into layers, and the organic layer was distilled to dryness under reduced pressure to obtain 60.5g dibromide. Yield: 69.2%, melting point: 132-135°C, yield: 69.6%.

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Abstract

The present invention relates to preparation process of 9,10-dibromo-9,10-dihydro-4-H-benzo-[4,5]-suberene-[1,2-b]-thienyl-4-one. The preparation process includes reaction between 9,10-dihydro-4-H-benzo- [4,5]-suberene- [1,2-b]-thienyl-4-one and brominating agent in aprotic solvent at the temperature from 0 deg.c to reflux temperature, and the post-treatment. The said aprotic solvent is C5-C14 alkane, C5-C14 cycloparaffin or their mixture. The preparation process has high selectivity and less side products.

Description

(1) Technical field [0001] The invention relates to a preparation method of 9,10-dibromo-9,10-dihydro-4-H-benzo[4,5]cyclohepteno[1,2-b]thiophen-4-one. (2) Background technology [0002] The scientific name of ketotifen is 4-(1-methylpiperidin-4-ylidene)-9,10-dihydro-4H-benzo[4,5]cyclohepteno[1,2-b]thiophene- 10-ketone, is a strong histamine H 1 Receptor antagonism and drugs that inhibit the release of allergic reaction mediators are mainly used in allergic rhinitis and allergic bronchial asthma. [0003] There are many reports about the synthesis of ketotifen. Considering its molecular formula structural characteristics, it is a suitable method to prepare ketotifen with tricyclic aromatic ketones, such as document Helvetica ChimicaActa-Vol.59.Fasc 3 (1976 )-Nr.87-88.Chemical Abstracts Vol64.1966, Offenlegungsschrift 2111071, 2144490, 2302970. US Patent US3682930, Japanese Patent, Zhao 56-6997 have all described this synthetic method. [0004] In the prior art, the compoun...

Claims

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Application Information

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IPC IPC(8): C07D333/78
Inventor 赵国标周明华陈剑文
Owner ZHEJIANG HUAHAI PHARMACEUTICAL CO LTD
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