Method for preparing 3-trifluoromethyl pyrrole boric acid

A technology of trifluoromethylpyrrole boronic acid and trifluoromethylpyrrole, which is applied in the field of organic chemical synthesis, and achieves the effects of high yield, good purity, and simple and easy preparation process

Inactive Publication Date: 2015-04-01
成都安斯利生物医药有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0002] 3-trifluoromethylpyrrole boronic acid is an important intermediate in the synthesis of medicines and pesticides, an

Method used

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  • Method for preparing 3-trifluoromethyl pyrrole boric acid

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Embodiment 1

[0032] Preparation of 4-ethoxy-3-ene trifluoroacetyl ketone:

[0033] Add 1620g of trifluoroacetic anhydride (7.71mol) and 6L of diethyl ether into a 12L reaction flask, cool to 0°C, slowly add 611g of ethylene ethyl ether (8.49mol) and 610g of pyridine (7.71mol) dropwise, complete the addition, and warm to room temperature , stirred for 12 hours, added 2L 1N dilute hydrochloric acid, separated the organic phase, washed with water, washed with saturated sodium chloride, dried with anhydrous magnesium sulfate, concentrated to generate 1200g of 4-ethoxy-3-ene trifluoroacetyl ketone, yield 92 %, 1H NMR (CDCl 3 ): 1.30ppm, triplet (3H); 4.02ppm, quadruplet (2H); 5.82ppm, doublet (1H); 7.82ppm, doublet (1H); 13CNMR (CDCl 3 ): 14.10ppm, 53.37ppm, 97.80ppm, 117.91ppm, 168.10ppm, 180.43ppm.

Embodiment 2

[0035] Preparation of 3-trifluoromethylpyrrole:

[0036] 817g 4-ethoxy-3-ene trifluoroacetylketone (4.86mol) and 510.16g hydrazine dihydrochloride (4.86mol) were dissolved in 2L of absolute ethanol, heated to reflux for 12 hours, cooled to room temperature, and the solvent was removed under reduced pressure, Diluted by adding water, extracted with dichloromethane, separated, dried, concentrated to give 450g of 3-trifluoromethylpyrrole, yield 68%, 1H NMR (CDCl 3 ): 6.71ppm, bimodal (1H); 7.76ppm, bimodal (1H); 13CNMR (CDCl 3 ): 103.82ppm, 123.06ppm, 130.36ppm, 142.70ppm.

Embodiment 3

[0038] Preparation of N-methyl-3-trifluoromethylpyrrole:

[0039] In a 5L reaction flask, dissolve 450g of 3-trifluoromethylpyrrole (3.29mol) in 2L of dimethylformamide, add 682.61g of potassium carbonate (4.94mol), cool to 0°C, and slowly add 701.03g of iodine dropwise Methane (4.94mol), raised to room temperature, stirred for 12 hours, quenched with water, extracted with ether, separated, dried, concentrated, and distilled under reduced pressure to obtain 385.49g of N-methyl-3-trifluoromethylpyrrole, Yield 78%, 1H NMR (CDCl 3 ): 4.85ppm, unimodal (3H); 6.50ppm, bimodal (1H); 7.35ppm, bimodal (1H); 13CNMR (CDCl 3 ): 39.19ppm, 104.39ppm, 122.78ppm, 131.46ppm, 142.31ppm.

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Abstract

The invention discloses a method for preparing 3-trifluoromethyl pyrrole boric acid, belonging to the technical field of organic chemical synthesis. The method is characterized by comprising the following steps: (I) with trifluoroacetic anhydride as a start raw material, generating 4-ethoxy-3-alkenyl trifluoroacetyl ketone through reaction between the trifluoroacetic anhydride and ethyl vinyl ether; (II) performing heating reflux of 4-ethoxy-3-alkenyl trifluoroacetyl ketone and hydrazine dihydrochloride in an ethanol solution to obtain 3-trifluoromethyl pyrrole; and (III) performing functional group conversion of 3-trifluoromethyl pyrrole to generate 1-methyl-3-trifluoromethyl-5-pyrrole boric acid, N-tert-butyl acyl-3-trifluoromethyl-5-pyrrole boric acid and 1-methyl-3-trifluoromethyl-4-pyrrole boric acid respectively. The method has the beneficial effects that the generated target compound has good purity and stable properties, the method is simple and easy to operate, and the preparation scale is easy to enlarge to realize industrial production.

Description

technical field [0001] The invention relates to the technical field of organic chemical synthesis, in particular to a method for preparing 3-trifluoromethylpyrrole boronic acid. Background technique [0002] 3-Trifluoromethylpyrrole boronic acid is an important intermediate in the synthesis of medicines and pesticides, and a chemical raw material with broad application prospects, but there are few reports on the synthesis methods of this kind of compounds. The innovation of the present invention is that starting from cheap and easy-to-obtain raw materials, by designing a reasonable organic synthesis route, a high-yield, high-purity intermediate compound is prepared, and then the structure of the intermediate compound is modified, and then the target compound is synthesized. The final target compound has good purity, is easy to scale up production, has low cost, and is easy to realize commercial products. Contents of the invention [0003] The present invention relates to ...

Claims

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Application Information

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IPC IPC(8): C07F5/02
CPCC07F5/025
Inventor 唐拥军莫珊刘玉琴
Owner 成都安斯利生物医药有限公司
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