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Preparation method of 3, 5-resacetophenone

A technology of dihydroxyacetophenone and dihydroxybenzoic acid, which is applied in the field of preparation of 3,5-dihydroxyacetophenone, can solve the problems of harsh conditions, difficult industrial application, low yield and the like, and achieves low cost and high production efficiency. The effect of simple process and strong industrial application value

Inactive Publication Date: 2014-05-14
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Tang He et al. used 3,5-dihydroxybenzoic acid as a raw material to obtain the target product through etherification, acyl chloride, ammoniation, Grignard reagent ketonization, and demethylation, with a total yield of 47% (China Pharmaceutical Industry Journal, 1998 ,29(11):521-522); Wu Haihong et al. used 3,5-dihydroxybenzoic acid as raw material to obtain the target product through esterification, benzyl protection, hydrolysis, Grignard reagent ketonization, and debenzylation. The rate is 65% (Synthetic Chemistry, 2000,8(2):146-150); Xia Changbin et al. used 3,5-dihydroxybenzoic acid as raw material to obtain The target product has a total yield of 60% (Chemical Reagents, 1999, 21(5): 307-308); Qin Ying et al. used benzoic acid as raw material, after nitrolation, acyl chloride, condensation, hydrolysis decarboxylation, reduction, heavy The target product is obtained by nitriding reaction, with a total yield of 46% (Anhui Chemical Industry, 1999, 92(2):27-43). The above-mentioned routes all have the disadvantages of harsh conditions, low yield, and difficulty in industrial application

Method used

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  • Preparation method of 3, 5-resacetophenone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] 1) Synthesis of ethyl 3,5-dihydroxybenzoate

[0025] Add 30.80g (200mmol) of 3,5-dihydroxybenzoic acid and 140mL of absolute ethanol to a 500mL four-neck flask in sequence, stir mechanically at room temperature until completely dissolved, slowly add 3.6mL of concentrated sulfuric acid dropwise, and heat to reflux for 8h. Ethanol was distilled off, after cooling to room temperature, 150 mL of methyl tert-butyl ether was added, followed by extraction with saturated aqueous solution of sodium bicarbonate (100 mL×2), saturated aqueous solution of sodium chloride (100 mL×1), and water (100 mL×2). The layer was dried over anhydrous magnesium sulfate overnight. Suction filtration, rotary evaporation of the filtrate, and vacuum drying gave 35.96 g of a white solid, yield 98.8%.

[0026] 2) Synthesis of ethyl 3,5-dibenzyloxybenzoate

[0027] Add 27.30g (150mmol) ethyl 3,5-dihydroxybenzoate, 60.00g (600mmol) potassium bicarbonate, 0.91g sodium iodide and 200mL acetone to a 500m...

Embodiment 2

[0037] 1) Synthesis of ethyl 3,5-dihydroxybenzoate

[0038] Add 30.80g (200mmol) of 3,5-dihydroxybenzoic acid and 170mL of absolute ethanol to a 500mL four-neck flask in sequence, stir mechanically at room temperature until completely dissolved, slowly add 2.4mL of concentrated sulfuric acid dropwise, and heat to reflux for 10h. Ethanol was distilled off, after cooling to room temperature, 150 mL of methyl tert-butyl ether was added, followed by extraction with saturated aqueous solution of sodium bicarbonate (100 mL×2), saturated aqueous solution of sodium chloride (100 mL×1), and water (100 mL×2). The layer was dried over anhydrous magnesium sulfate overnight. Suction filtration, rotary evaporation of the filtrate, and vacuum drying gave 35.33 g of white solid, yield 97.1%.

[0039] 2) Synthesis of ethyl 3,5-dibenzyloxybenzoate

[0040] Add 27.30g (150mmol) ethyl 3,5-dihydroxybenzoate, 72.45g (525mmol) potassium carbonate, 1.00g sodium iodide and 140mL acetone into a 500mL...

Embodiment 3

[0050] 1) Synthesis of ethyl 3,5-dihydroxybenzoate

[0051] Add 30.80g (200mmol) of 3,5-dihydroxybenzoic acid and 200mL of absolute ethanol to a 500mL four-neck flask in sequence, stir mechanically at room temperature until completely dissolved, slowly add 3.5mL of concentrated sulfuric acid dropwise, and heat to reflux for 12h. Ethanol was distilled off, after cooling to room temperature, 150 mL of methyl tert-butyl ether was added, followed by extraction with saturated aqueous solution of sodium bicarbonate (100 mL×2), saturated aqueous solution of sodium chloride (100 mL×1), and water (100 mL×2). The layer was dried over anhydrous magnesium sulfate overnight. Suction filtration, rotary evaporation of the filtrate, and vacuum drying gave 35.56 g of white solid, yield 97.7%.

[0052] 2) Synthesis of ethyl 3,5-dibenzyloxybenzoate

[0053] Add 32.55g (179mmol) ethyl 3,5-dihydroxybenzoate, 61.7g (447mmol) potassium carbonate, 1.50g sodium iodide and 165mL acetone to a 500mL fo...

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Abstract

The invention discloses a preparation method of 3,5-resacetophenone, which takes 3,5-dihydroxy-benzoic acid as a raw material, and the 3,5-resacetophenone can be prepared by esterification, benzylation, hydrolysis, nucleophilic substitution, hydrolysis, decarboxylation and debenzylation. The preparation method is mild in preparation condition, simple in technology, low in cost and higher in yield, and has higher industrial application value.

Description

technical field [0001] The invention relates to a preparation method of the key intermediate 3,5-dihydroxyacetophenone used for treating asthma (such as ocinaline, fenoterol, bambuterol, terbutaline, etc.). Background technique [0002] At present, most of the methods for preparing 3,5-dihydroxyacetophenone use 3,5-dihydroxybenzoic acid as a raw material, and use the Grignard reagent method to synthesize 3,5-dihydroxyacetophenone. Tang He et al. used 3,5-dihydroxybenzoic acid as a raw material to obtain the target product through etherification, acyl chloride, ammoniation, Grignard reagent ketonization, and demethylation, with a total yield of 47% (China Pharmaceutical Industry Journal, 1998 ,29(11):521-522); Wu Haihong et al. used 3,5-dihydroxybenzoic acid as raw material to obtain the target product through esterification, benzyl protection, hydrolysis, Grignard reagent ketonization, and debenzylation. The rate is 65% (Synthetic Chemistry, 2000,8(2):146-150); Xia Changbin...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C49/825C07C45/64
Inventor 戴立言唐林淋王晓钟陈英奇
Owner ZHEJIANG UNIV
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