Preparation method of 4-trifluoromethyl nicotinic acid

A technology of trifluoromethylnicotinic acid and trifluoromethylpyridine, which is applied in the field of compound preparation, can solve the problems of difficult realization, harsh conditions, and impossibility of industrialization, and achieve the effects of reduced production costs, fewer by-products, and low prices

Inactive Publication Date: 2010-10-06
XIHUA UNIV
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  • Application Information

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Problems solved by technology

This route uses sodium hydride and requires the reaction temperature to be controlled

Method used

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  • Preparation method of 4-trifluoromethyl nicotinic acid
  • Preparation method of 4-trifluoromethyl nicotinic acid
  • Preparation method of 4-trifluoromethyl nicotinic acid

Examples

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Embodiment 1

[0046] (1) Preparation of 2,6-dihydroxy-3-cyano-4-trifluoromethylpyridine

[0047]In a 100mL three-necked flask equipped with a reflux condenser and a thermometer, add 12g (0.142mol) of cyanoacetamide 2, 30mL of anhydrous methanol, and 20mL (0.136mol) of 4,4,4-trifluoroacetoacetic acid in sequence under stirring Ethyl ester 1. Magnetic force. Heat and stir in an oil bath until it reaches reflux. After the cyanoacetamide is completely dissolved, slowly add the prepared methanolic potassium hydroxide solution (9g / 20mL) dropwise, and drop it over within 24 hours. After dissolution, the color of the solution gradually deepened from yellow to orange-red, and then a white precipitate began to form. During the reaction, a small amount was dissolved in absolute ethanol for TLC detection, and the reflux continued for 6 hours. After the reaction was completed, it was left to stand, cooled, taken out for suction filtration, washed with methanol, water, and methanol in sequence, and the ...

Embodiment 2

[0055] (1) Preparation of 2,6-dihydroxy-3-cyano-4-trifluoromethylpyridine

[0056] In a 100mL three-necked flask equipped with a reflux condenser and a thermometer, add 12g (0.142mol) of cyanoacetamide 2, 30mL of anhydrous methanol, and 20mL (0.136mol) of 4,4,4-trifluoroacetoacetic acid in sequence under stirring Ethyl ester 1. Magnetic force. Heat and stir in an oil bath until it reaches reflux. After the cyanoacetamide is completely dissolved, slowly add the prepared methanolic potassium hydroxide solution (9g / 20mL) dropwise, and drop it over within 24 hours. After dissolution, the color of the solution gradually deepened from yellow to orange-red, and then a white precipitate began to form. During the reaction, a small amount was dissolved in absolute ethanol for TLC detection, and the reflux continued for 6 hours. After the reaction was completed, it was left to stand, cooled, taken out for suction filtration, washed with methanol, water, and methanol in sequence, and the...

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Abstract

The invention discloses a preparation method of 4-trifluoromethyl nicotinic acid, and relates to a preparation method of a compound, which comprises the following steps: taking 4,4,4-trifluoroacetoacetate and cyanoacetamide as raw materials, taking potassium hydroxide as a catalyst to obtain 2,6-dihydroxy-3-cyano-4-trifluoromethyl pyridine by cyclization, then using POCl3 to chloridize to obtain 2,6-chloro-3-cyano-4-trifluoromethyl pyridine, and finally carrying out Pd/C catalytic hydrogenolysis or hydrogenolysis and then hydrolyzing or hydrolyzing and then carrying out Pd/C catalytic hydrogenolysis to obtain the target product 4-trifluoromethyl nicotinic acid. The invention provides a feasible and safe preparation method of the 4-trifluoromethyl nicotinic acid, which has certain economic advantages and can be applied to industrial production.

Description

technical field [0001] The invention relates to a preparation method of compounds, in particular to a preparation method of 4-trifluoromethylnicotinic acid. Background technique [0002] 4-Trifluoromethylnicotinic acid and its salts are the active ingredients of agricultural chemicals, and are usually synthesized as important precursors of agricultural chemicals or pharmaceuticals. The route of synthesizing 4-trifluoromethyl nicotinic acid mainly contains following several kinds at present: [0003] Among them, the most widely used is the synthetic route of obtaining 4-trifluoromethylnicotinic acid by reacting 4-trifluoromethylpyridine as a raw material with LDA and carbon dioxide. Found in the document e-EROS Encyclopedia of Reagents for Organic Synthesis (2001) and the document European Journal of Organic Chemistry (2003), (8), 1569-1575. [0004] [0005] The similar route also has document European Journal of Organic Chemistry (2003), (8), 1559-1568, US5360806 repor...

Claims

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Application Information

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IPC IPC(8): C07D213/80C07D213/803
Inventor 马梦林
Owner XIHUA UNIV
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