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Synthetic method of o-hydroxyacetophenone

A technology for the synthesis of o-hydroxyacetophenone and its synthesis method, which is applied in the field of synthesis of pharmaceutical intermediates, can solve the problems of being unsuitable for industrial application, difficult to handle, and difficult to prepare catalysts, and achieve good industrial application prospects, easy operation, and high product yield. high effect

Inactive Publication Date: 2008-10-08
ZHEJIANG SCI-TECH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The catalyst used in this method is difficult to prepare, and the reaction must be carried out at a very high temperature, which is not easy to handle and is not suitable for industrial applications.

Method used

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  • Synthetic method of o-hydroxyacetophenone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] 1) Preparation of 4-acetamidophenol acetate

[0030] Add paracetamol (45.4g, 0.3mol), acetyl chloride (33g, 0.42mol) and anhydrous potassium carbonate (41.4g, 0.3mol) to 500ml of ethyl acetate, stir and heat, and reflux at 78°C for 18 hours . The recovered solvent was evaporated under normal pressure, cooled, and 350ml of water was added to precipitate a solid, which was filtered with suction and washed with water several times to obtain 55.7g of a white solid, with a yield of 96.1%. The experimental data are as follows:

[0031] mp 158-159°C; 1 HNMR (400MHz, CDCl 3 )δ (ppm): 7.50-7.47 (d, 2H, ArH), 7.33 (s, 1H, NHCO), 7.04-7.02 (d, 2H, ArH), 2.29 (s, 3H, CH 3 COO), 2.16(s, 3H, CH 3 CONH). IR(KBr)cm -1 : 3369, 3294, 1751, 1691, 1608, 1541, 1507, 1365, 1241

[0032] 2) Preparation of 2-hydroxyl 5-acetamidoacetophenone

[0033] Dissolve 4-acetamidophenol acetate (19.3g, 0.1mol) in o-dichlorobenzene (150ml), add anhydrous aluminum trichloride (33.3g, 0.25mol), sti...

Embodiment 2

[0047] 1) Preparation of 4-acetamidophenol acetate

[0048] According to the method of step 1) in Example 1, the charging amount of acetyl chloride was 23.6g, and 53.5g of 4-acetamidophenol acetate was obtained, and the yield was 92.3%.

[0049] 2) Preparation of 2-hydroxyl 5-acetamidoacetophenone

[0050] According to the method of step 2) in Example 1, the feeding amount of anhydrous aluminum trichloride was 13.4 g, and 15.5 g of 2-hydroxyl 5-acetamidoacetophenone was obtained after the reaction, and the yield was 80.3%.

[0051] 3) Preparation of 2-hydroxyl 5-aminoacetophenone

[0052] According to the method of step 3) in the embodiment 1, the charging amount of 15% dilute hydrochloric acid is 121.6ml, after the reaction, 13.7g of 2-hydroxyl 5-aminoacetophenone is obtained, and the yield is 90.1%.

[0053] 4) preparation of o-hydroxyacetophenone

[0054] According to the method of step 4) in Example 1, the feeding amount of concentrated sulfuric acid is 49.0g, and the r...

Embodiment 3

[0056] 1) Preparation of 4-acetamidophenol acetate

[0057] According to the method of step 1) in Example 1, the charging amount of acetyl chloride was 141.3 g, and 54.8 g of 4-acetamidophenol acetate was obtained, and the yield was 94.5%.

[0058] 2) Preparation of 2-hydroxyl 5-acetamidoacetophenone

[0059] According to the method of step 2) in Example 1, the feeding amount of anhydrous aluminum trichloride was 133.5 g, and 14.5 g of 2-hydroxyl 5-acetamidoacetophenone was obtained after the reaction, and the yield was 75.1%.

[0060] 3) Preparation of 2-hydroxyl 5-aminoacetophenone

[0061] According to the method of step 3) in Example 1, the feeding amount of 10% dilute hydrochloric acid is 91.2ml, and after the reaction, 13.8g of 2-hydroxyl 5-aminoacetophenone is obtained, and the yield is 91.4%.

[0062] 4) preparation of o-hydroxyacetophenone

[0063] According to the method of step 4) in embodiment 1, NaNO 2 The charging amount is 20.7g, and after the reaction, 36.2...

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Abstract

The invention discloses a method to synthesize 2-hydroxy-acetophenone, which takes low-cost paracetamol as material and prepares 2-hydroxy-acetophenone through acylation, Fries recomposition, acylation through hydrolyzation, and deaminization through diazotization. The material used in the method is easy to get and is low in cost; the process is simple, with mild condition and short period; the yield is high and the product is high in purity; therefore the method is of good prospect in industrial application.

Description

technical field [0001] The invention relates to a method for synthesizing a drug intermediate, in particular to a method for synthesizing o-hydroxyacetophenone. Background technique [0002] O-hydroxyacetophenone (English name O-hydroxy-acetophenon) is an important chemical raw material, which is widely used in the research and industrial production of fine chemical products such as medicine and pesticides. Key intermediates of choleretic drugs. [0003] There have been related reports on the synthesis of o-hydroxyacetophenone. Wang Guoxi ("Chinese Journal of Pharmaceutical Industry", 1999, 30 (5), 232-233) reported that phenol was used as a raw material to react with acetic anhydride to generate an ester, and then Fries rearrangement was carried out under a carbon disulfide solvent to obtain o-hydroxyacetophenone and p-hydroxyacetophenone in a ratio of 2:3. The disadvantage of this method is that carbon disulfide is used as a solvent, which has a pungent smell, is volati...

Claims

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Application Information

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IPC IPC(8): C07C49/825C07C45/46
Inventor 朱锦桃宋光伟陈刚
Owner ZHEJIANG SCI-TECH UNIV
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