Catalytic synthesis of 3-pyrrolin-2-one in emulsion with titanocene dichloride and Bronsted acid

A technology of Bronsted acid and titanocene dichloride is applied in the field of synthesis of pyrrolinone compounds to achieve the effect of large reaction specific surface area, increase local concentration and avoid by-products

Active Publication Date: 2021-10-01
SHAANXI NORMAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing 3-pyrroline-2-one compound preparation methods, and provide a catalyst that is cheap, easy to obtain, non-toxic, mild in reaction conditions, short in reaction time, single in reaction products, and safe Preparation method of 3-pyrroline-2-one compounds with high efficiency and high yield

Method used

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  • Catalytic synthesis of 3-pyrrolin-2-one in emulsion with titanocene dichloride and Bronsted acid
  • Catalytic synthesis of 3-pyrrolin-2-one in emulsion with titanocene dichloride and Bronsted acid
  • Catalytic synthesis of 3-pyrrolin-2-one in emulsion with titanocene dichloride and Bronsted acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Synthesis of ethyl 2-methyl-5-oxo-1-phenyl-4-(phenylamino)-2,5-dihydro-1H-pyrrole-2-carboxylate with the following structural formula

[0018]

[0019] Add 181 μL (2 mmol) of aniline, 274 μL (2.5 mmol) of ethyl pyruvate, 0.01245 g (0.05 mmol) of titanocene dichloride, 0.01671 g (0.1 mmol) of p-nitrobenzoic acid, 1333 μL of distilled water, and 667 μL of chlorobenzene to the sample bottle, stirred and reacted at 50° C. for 6 hours, stopped the reaction, naturally cooled to room temperature, and separated by column chromatography to obtain solid 2-methyl-5-oxo-1-phenyl-4-(phenylamino)-2, 5-Dihydro-1H-pyrrole-2-carboxylic acid ethyl ester, its yield is 94%, and the structural characterization data are: 1 HNMR (600MHz, CDCl 3 )δ7.41(dt, J=8.7,7.8Hz,4H),7.37-7.31(m,2H),7.29(t,J=7.2Hz,1H),7.08(d,J=7.7Hz,2H), 7.00(t,J=7.4Hz,1H),6.68(s,1H),5.99(s,1H),4.20(dddd,J=25.0,10.8,7.1,3.7Hz,2H),1.66(s,3H) ,1.24(t,J=7.1Hz,3H); 13 C NMR (101MHz, CDCl 3 ( s), 117.03(s), 107.69(s),...

Embodiment 2

[0021] Synthesis of 1-(4-ethylphenyl)-4-((4-ethylphenyl)amino)-2-methyl-5-oxo-2,5-dihydro-1H-pyrrole- 2-Ethyl carboxylate

[0022]

[0023] In this example, the aniline in Example 1 was replaced with equimolar 4-ethylaniline, and the other steps were the same as in Example 1 to obtain solid 1-(4-ethylphenyl)-4-((4-ethylphenyl) Phenyl)amino)-2-methyl-5-oxo-2,5-dihydro-1H-pyrrole-2-carboxylic acid ethyl ester, the yield is 93%, and the structural characterization data are: 1 H NMR (600MHz, CDCl 3 )δ7.20(d, J=8.4Hz, 2H), 7.16(d, J=8.4Hz, 2H), 7.07(d, J=8.3Hz, 2H), 6.93(d, J=8.4Hz, 2H) ,5.85(s,1H),4.16-4.03(m,2H),2.56(dq,J=31.7,7.6Hz,4H),1.55(s,3H),1.16(ddd,J=12.8,9.2,6.7Hz ,10H); 13 C NMR (151MHz, CDCl 3 )δ171.72(s),167.58(s),143.04(s),138.79(s),137.57(s),133.97(s),133.45(s),128.72(s),128.57(s),125.75( s), 117.11(s), 106.86(s), 68.74(s), 62.09(s), 28.44(s), 28.17(s), 21.31(s), 15.78(s), 15.41(s), 14.06( s).

Embodiment 3

[0025] Synthesis of 1-(4-methoxyphenyl)-4-((4-methoxyphenyl)amino)-2-methyl-5-oxo-2,5-dihydro-1H- Ethyl pyrrole-2-carboxylate

[0026]

[0027] In this example, the aniline in Example 1 was replaced with equimolar p-methoxyaniline, and the other steps were the same as in Example 1 to obtain solid 1-(4-methoxyphenyl)-4-((4-methoxyphenyl) Oxyphenyl)amino)-2-methyl-5-oxo-2,5-dihydro-1H-pyrrole-2-carboxylic acid ethyl ester, the yield is 96%, and the structural characterization data are: 1 H NMR (600MHz, CDCl 3 )δ7.22-7.18 (m, 2H), 6.96 (d, J = 8.8Hz, 2H), 6.87 (d, J = 8.8Hz, 2H), 6.82 (d, J = 8.8Hz, 2H), 6.40 ( s,1H),5.76(s,1H),4.17-4.05(m,2H),3.74(d,J=14.5Hz,6H),1.54(s,3H),1.18(t,J=7.1Hz,3H ); 13 C NMR (151MHz, CDCl 3 )δ170.59(s),166.71(s),157.63(s),153.69(s),133.47(s),127.51(s),127.12(s),117.70(s),113.72(s),113.43( s), 104.79(s), 67.86(s), 60.99(s), 54.59(s), 54.43(s), 20.44(s), 13.06(s).

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Abstract

The invention discloses a method for catalyzing and synthesizing 3-pyrroline-2-ketone in an emulsion in cooperation with titanocene dichloride and Bronsted acid. The method uses titanocene dichloride and acid as catalysts to replace benzene and water It is used as a solvent to construct an emulsion system, so that aniline compounds and ethyl pyruvate or methyl pyruvate undergo intermolecular dehydration under mild conditions, undergo a ring closure process, and generate 3-pyrroline-2-ketone compounds. The invention has simple operation, mild reaction conditions, high selectivity, effectively avoids the generation of by-product quinoline and multi-substituted hydroquinoline, less catalyst consumption, lower cost, good substrate applicability, high yield of target compound, and can Widely used in the preparation of natural products pyrrolinone compounds.

Description

technical field [0001] The invention belongs to the technical field of synthesis of pyrrolinone compounds, and in particular relates to a method for catalytically synthesizing 3-pyrroline 2-one in emulsion in cooperation with titanocene dichloride and Bronsted acid. Background technique [0002] 3-Pyrroline-2-one is not only the core structure of biologically active natural products and drugs (including oligopyrrole plant pigments and heme metabolites, terpenoids, peptides, etc.), but also the preparation of nitrogen heterocycles and γ - building blocks of amino acid derivatives. [0003] There are various methods for the synthesis of 3-pyrrolin-2-one compounds, in particular reduction of maleimide, oxidation of pyrrole or pyrrole-2-carbaldehyde, reductive cyclization of β-cyano ester, condensation of ketoamide. Most of these synthetic methods use precious metals and organic solvents, the product yields are moderately low, and the reaction takes a long time. Recently, it h...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D207/38
CPCC07D207/38
Inventor 孙华明马富余吴莹孙晓吴亚高子伟
Owner SHAANXI NORMAL UNIV
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