Method for preparing 2-amino-4'-fluorobenzophenone

A technology of benzophenone and o-nitrobenzoic acid, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve the problems of low total yield, many reagents, complicated operation, etc., and meet the reaction conditions Moderate and controllable, convenient and controllable operation, mild reaction conditions

Active Publication Date: 2018-02-02
ANHUI QINGYUN PHARMA & CHEM
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Problems solved by technology

[0004] Route 1, using o-nitrobenzoic acid as the starting material, the product is obtained through acid chloride reaction, Friedel-Crafts acylation, and reduction. Although the route is relatively short, the acid chloride reaction uses sulfuryl chloride to produce polluting by-products, etc. There are environmental protection problems in the industrial scale-up of this reaction; on the other hand, the raw material cost of this route is relatively high, and it is difficult to realize large-scale industrialization;
[0005] Route 2, using phthalic anhydride as the starting material, first performs Friedel-Crafts acylation reaction with fluorobenzene to obtain p-fluorobenzoylbenzoic acid, and then undergoes acid chloride reaction, amidation reaction, and Hofmann degradation to obtain 2- Amino-4

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  • Method for preparing 2-amino-4'-fluorobenzophenone

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Example Embodiment

[0046] Example 1

[0047] A method for preparing 2-amino-4'-fluoro-benzophenone includes the following steps: the oxidation reaction of o-nitrotoluene with trichloroisocyanuric acid, tetramethylpiperidine nitrogen oxide and sodium bromide is obtained O-nitrobenzoic acid; followed by acid chlorination with trichloromethyl carbonate to obtain o-nitrobenzoyl chloride; and then with fluorobenzene and aluminum trichloride for Friedel-Crafts reaction to obtain 2-nitro-4'-fluoro- Benzophenone; finally reduced by hydrogen to obtain 2-amino-4'-fluoro-benzophenone.

Example Embodiment

[0048] Example 2

[0049] A method for preparing 2-amino-4'-fluoro-benzophenone includes the following steps:

[0050] Take o-nitrotoluene, tetramethylpiperidine nitrogen oxide, sodium bromide, and the reaction solvent for the oxidation reaction, heat up to 0°C, add trichloroisocyanuric acid, keep for 24h, quench the reaction with methanol, and filter the filtrate. The organic layer was extracted with dichloromethane, washed, dried, concentrated under reduced pressure, and recrystallized with a mixed solvent of ethyl acetate and petroleum ether to obtain o-nitrobenzoic acid. The reaction solvent was a mixed solvent of dichloromethane and water. Among them, the volume ratio of dichloromethane and water is 10:1, the molar ratio of trichloroisocyanuric acid, tetramethylpiperidine nitrogen oxide, and sodium bromide is 1:0.001:0.2, and the molar ratio of o-nitrotoluene and trichloro The molar ratio of isocyanuric acid is 1:0.8;

[0051] O-nitrobenzoic acid and trichloromethyl carbonate ...

Example Embodiment

[0054] Example 3

[0055] A method for preparing 2-amino-4'-fluoro-benzophenone includes the following steps:

[0056] Take o-nitrotoluene, tetramethylpiperidine nitrogen oxide, sodium bromide, and the reaction solvent for the oxidation reaction, heat up to 30°C, add trichloroisocyanuric acid, keep it for 10 hours, quench the reaction with methanol, and filter the filtrate. The organic layer was extracted with dichloromethane, washed, dried, concentrated under reduced pressure, and recrystallized with a mixed solvent of ethyl acetate and petroleum ether to obtain o-nitrobenzoic acid. The reaction solvent was a mixed solvent of dichloromethane and water. Among them, the volume ratio of dichloromethane and water is 10:1, the molar ratio of trichloroisocyanuric acid, tetramethylpiperidine nitrogen oxide, and sodium bromide is 1:0.1:0.05, and the molar ratio of o-nitrotoluene and trichloro The molar ratio of isocyanuric acid is 1:2;

[0057] Take o-nitrobenzoic acid, trichloromethyl ca...

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Abstract

The invention discloses a method for preparing 2-amino-4'-fluorobenzophenone. The method comprises the following steps: o-nitrotoluene, trichloroisocyanuric acid, tetramethylpiperidine nitrogen oxideand sodium bromide undergo an oxidation reaction to obtain o-nitrobenzoic acid; the o-nitrobenzoic acid and trichloromethyl carbonate undergo an acylating chlorination to obtain o-nitrobenzoyl chloride; the o-nitrobenzoyl chloride, fluorobenzene and aluminum trichloride undergo a Friedel-Crafts reaction to obtain 2-nitro-4'-fluorobenzophenone; and the 2-nitro-4'-fluorobenzophenone is reduced by hydrogen to the 2-amino-4'-fluorobenzophenone. The method has the advantages of green and environmentally-friendly synthesis route, cheap and easily available initial raw materials, low cost, convenience in operation, suitableness for industrial production, and high yield, and the prepared 2-amino-4'-fluorobenzophenone has a good purity.

Description

technical field [0001] The invention relates to the technical field of chemical substance preparation, in particular to a method for preparing 2-amino-4'-fluoro-benzophenone. Background technique [0002] Pitavastatin calcium is the third-generation statin drug, and it is one of the statin drugs with better blood lipid-lowering effect in international clinical application. It has the characteristics of high efficiency, safety, and good tolerance. 2-Amino-4'-fluoro-benzophenone is a key intermediate used in the production of pitavastatin calcium. [0003] At present, the synthetic routes of 2-amino-4'-fluoro-benzophenone mainly contain the following methods: [0004] Route 1, using o-nitrobenzoic acid as the starting material, the product is obtained through acid chloride reaction, Friedel-Crafts acylation, and reduction. Although the route is relatively short, the acid chloride reaction uses sulfuryl chloride to produce polluting by-products, etc. There are environmental p...

Claims

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Application Information

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IPC IPC(8): C07C221/00C07C225/22
CPCC07C201/12C07C221/00C07C225/22C07C205/45C07C205/57
Inventor 黄欢黄庆国周健
Owner ANHUI QINGYUN PHARMA & CHEM
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