Method for preparing polysubstituted pyrazole through one-pot reaction of substituted alkyne and hydrazine or hydrazine substitute

A technology of substitution and multi-substitution, applied in the field of preparation of pharmaceutical intermediates, can solve problems such as unreported reaction of substituted pyrazole compounds, and achieve the effects of cheap raw materials, simple process and easy preparation

Active Publication Date: 2019-01-18
陕西君境迈德生物医药科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, there is no report on the preparation of substituted pyrazoles under visible light conditions by using substituted alkynes and hydrazine or hydrazine substitutes

Method used

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  • Method for preparing polysubstituted pyrazole through one-pot reaction of substituted alkyne and hydrazine or hydrazine substitute
  • Method for preparing polysubstituted pyrazole through one-pot reaction of substituted alkyne and hydrazine or hydrazine substitute

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Add 2ml of solvent dimethyl sulfoxide, 0.102g (1mmol) of phenylacetylene, and 0.038g (0.2mmol) of cuprous iodide to a 10ml reaction tube in turn, irradiate with 12W blue LED for 7 hours, and react at room temperature. After about 8 hours of reaction, phenylacetylene disappeared completely, then 0.2 g (4 mmol) of hydrazine hydrate and 12.8 mg (0.02 mmol) of photocatalyst methylene blue were added, and the reaction at room temperature was continued for 48 hours. After the reaction, it was extracted three times with water and ethyl acetate. The aqueous layer was removed, and the organic layer was dried over anhydrous sodium sulfate. The solvent was removed by a rotary evaporator, and then purified by silica gel chromatography (ethyl acetate / petroleum ether=1 / 10) to obtain pure 3-benzyl-5-phenyl-1H-pyrazole in a yield of 77%. 1 H NMR (400MHz, CDCl 3 )δ9.93(brs,1H),7.74-7.71(d,J=8.0Hz,2H),7.38-7.24(m,8H),6.37(s,1H),3.99(s,3H). 13 CNMR (100MHz, CDCl 3 )δ149.0, 147.6, 138.7...

Embodiment 2

[0019] In Reaction Example 1, except that 0.102 g (1 mmol) of phenylacetylene was changed to 0.116 g (1 mmol) of 1-ethynyl-4-methylbenzene, the reaction was carried out in the same manner as in Example 1. The yield of 3-(4-methylbenzyl)-5-(4-methylphenyl)-1H-pyrazole was 71%. H NMR (400MHz, CDCl 3 )δ9.12(brs,1H),7.47-7.45(d,J=8.0Hz,2H),7.08-7.04(m,6H),6.31(s,1H),3.87(s,2H),2.27(s ,3H),2.24(s,3H). 13 C NMR (100MHz, CDCl 3 )δ149.0, 147.8, 137.8, 136.2, 135.4, 129.4, 129.3, 129.1, 128.6, 125.5, 101.7, 32.8, 21.3, 21.0. HRMS (ESI) calcd for C 18 h 19 N 2 (M+H) + 263.1556, found 263.1548.

Embodiment 3

[0021] In Reaction Example 1, except that 0.102 grams (1 mmol) of phenylacetylene was changed to 0.116 grams (1 moml) of 1-ethynyl-3-methylbenzene, the reaction was carried out in the same manner as in Example 1. The yield of 3-(3-methylbenzyl)-5-(3-methylphenyl)-1H-pyrazole was 64%. 1 H NMR (400MHz, CDCl 3 )δ10.75(brs,1H),7.47-7.43(m,2H),7.83-7.11(m,2H),7.05-6.96(m,4H),6.26(s,1H),3.86(s,2H) ,2.26(s,3H),2.25(s,3H). 13 C NMR (100MHz, CDCl 3 )δ149.1,147.8,138.7,138.3,138.2,132.0,129.6,128.7,128.6,128.5,127.3,126.5,125.8,122.9,102.0,33.1,21.4,21.3.HRMS(ESI)calcd for C 18 h 19 N 2 (M+H) + 263.1458, found 263.1464.

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Abstract

The invention belongs to the technical field of drug intermediate preparation and specifically relates to a method for preparing polysubstituted pyrazole through one-pot reaction of substituted alkyneand hydrazine or hydrazine substitute. The polysubstituted pyrazole is generated from oxidation addition reaction of substituted alkyne and hydrazine or hydrazine substitute served as raw materials and air served as oxidizing agent under the existence of photo-sensitizer and copper salt and under the irradiation of visible light. The method provided by the invention has the advantages of low costof raw materials, simple and convenient process and easiness in industrial preparation.

Description

technical field [0001] The invention belongs to the technical field of preparation of pharmaceutical intermediates, in particular to a method for preparing polysubstituted pyrazoles by reacting substituted alkynes with hydrazine or hydrazine substitutes in one pot. Background technique [0002] Pyrazole compounds are intermediates of medicines and dyes. In the application of medicine, pyrazole compounds have curative effect on many diseases; in the application of pesticides, pyrazole compounds have insecticidal, bactericidal and herbicidal activities, and exhibit high efficiency, low toxicity and structural diversity. [0003] Pyrazoles are typical five-membered nitrogen-heterocyclic organic compounds, which exhibit many unique biological activities. It has a very important application in drug research and development. Pyrazolate tartrate, pyrazole becamine, etc. all contain pyrazole structure. Many pyrazole compounds are used in clinical therapeutic fields, such as anti-i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D231/12
CPCC07D231/12
Inventor 朱纯银巩新池
Owner 陕西君境迈德生物医药科技有限公司
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