Method for directly synthesizing oxazolidin-2,4-one heterocyclic compound from alkyne amide

A technology of heterocyclic compounds and alkyne amides, which is applied in the field of organic chemical synthesis, can solve the problems of difficult electrolysis, cumbersome synthesis steps, and long reaction time, and achieve the effects of high yield, high reaction efficiency, and simple operation

Active Publication Date: 2020-11-17
NANJING TECH UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] In summary, the current synthetic methods of oxazolidine-2,4-diketone heterocyclic compounds have the following disadvantages: 1. The synthetic steps are cumbersome, requiring at least two steps, and the reaction time is longer; 2. The reaction requires 3. Except for the electrolysis method, the reaction yield is almost all below 75%; 4. The electrolysis method is not easy to operate

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  • Method for directly synthesizing oxazolidin-2,4-one heterocyclic compound from alkyne amide
  • Method for directly synthesizing oxazolidin-2,4-one heterocyclic compound from alkyne amide

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Effect test

Embodiment 1

[0018] In air, 1.8425 g of N-phenylethynyl-N-benzylcarbamate tert-butyl ester, 0.2124 g of 1-chloromethyl-4-fluoro-1,4-azonium bicyclo[2.2.2] Octane bistetrafluoroborate (Selectfluor TM ) into a 100mL reaction flask, 60mL dimethyl sulfoxide was added, and placed in an oil bath at 100°C to react for 1.5 hours. Cool the reaction solution to room temperature, add 20 mL of water, then extract three times with 60 mL of ethyl acetate, combine the organic phases, wash with 30 mL of saturated brine, dry over anhydrous sodium sulfate, filter, distill off excess solvent under reduced pressure, and perform column chromatography (Petroleum ether:ethyl acetate=10:1) to obtain 1.4821 g of 3-phenyl-5-benzyloxazolidine-2,4-dione. Melting point 114.1-114.9°C, 1 H NMR (400MHz, CDCl 3 )δ7.41-7.32 (m, 10H), 5.71 (s, 1H), 4.75-4.67 (m, 2H); 13 C NMR (100MHz, CDCl 3 )δ170.9, 155.1, 134.6, 131.6, 129.8, 129.1, 128.9, 128.8, 128.6, 126.1, 80.2, 44.0.

Embodiment 2

[0020] In air, successively add 1.7581 g of tert-butyl N-phenylethynyl-N-phenylcarbamate, 0.2124 g of 1-chloromethyl-4-fluoro-1,4-azoniumbicyclo[2.2.2]octane Alkane bistetrafluoroborate (Selectfluor TM ) into a 100 mL reaction flask, 60 mL of dimethyl sulfoxide was added, and the reaction was carried out in an oil bath at 100°C for 1 hour. Cool the reaction solution to room temperature, add 20 mL of water, then extract three times with 60 mL of ethyl acetate, combine the organic phases, wash with 30 mL of saturated brine, dry over anhydrous sodium sulfate, filter, distill off excess solvent under reduced pressure, and use petroleum ether Recrystallization from ethyl acetate gave 1.3983 g of 3,5-diphenyloxazolidine-2,4-dione. Melting point 118.7-120.4°C, 1 H NMR (400MHz, CDCl 3 )δ7.26-7.51(m, 10H), 5.92(s, 1H). 13 C NMR (100MHz, CDCl 3 )δ170.0, 154.0, 131.5, 130.7, 130.0, 129.4, 129.2, 129.1, 126.08, 125.6, 79.9.

Embodiment 3

[0022] In air, sequentially add 0.2571 g of tert-butyl N-phenylethynyl-N-allyl carbamate, 0.0176 g of 50% tetrafluoroboric acid aqueous solution into a 20 mL reaction tube, add 15 mL of N,N-dimethyl Formamide was placed in an oil bath at 120°C for 3 hours. Cool the reaction solution to room temperature, add 10 mL of water, then extract three times with 20 mL of ethyl acetate, combine the organic phases, wash with 20 mL of 5% dilute hydrochloric acid, 30 mL of saturated saline, dry over anhydrous magnesium sulfate, filter, and distill off excess under reduced pressure. solvent, column chromatography (petroleum ether: ethyl acetate = 10:1) to obtain 0.1945 g of 3-allyl-5-phenyloxazolidine-2,4-dione. Melting point 60.1-61.5°C, 1 H NMR (400MHz, CDCl 3 )δ7.43 (m, 5H), 5.88-5.80 (m, 1H), 5.75 (s, 1H) 5.33-5.26 (t, J = 10.2Hz, 2H), 4.20-4.18 (m, 2H); 13 C NMR (100MHz, CDCl 3 )δ 170.7, 154.9, 131.5, 129.8, 129.6, 129.2, 126.0, 119.6, 80.2, 42.4.

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Abstract

The invention discloses a novel method for directly synthesizing an oxazolidin-2,4-one heterocyclic compound from an alkyne amide raw material. According to the method, Bronsted acid or tetrafluoroborate with a molar fraction of 10% is used as a catalyst, nitromethane, N-methylpyrrolidone, dimethyl sulfoxide or N,N-dimethylformamide is used as a solvent a reaction is carried out for 0.5-24 h at atemperature of 50-150 DEG C under the condition ofair,then vacuum concentration is carried out, and recrystallization or column chromatography purification is carried out, so the oxazolidin-2,4-one heterocyclic compound is obtained. The yield of the oxazolidin-2,4-one heterocyclic compound is 89-92%. The method has high catalytic reaction activity, realizes the preparation of the oxazolidin-2,4-one heterocyclic compound from an alkyne amide raw material for the first time, is high in yield, wide in the range of applicable substrates and capable of synthesizing the oxazolidin-2,4-one heterocyclic compound on a gram-level scale, and has the advantages of insensitivity to air, high chemical selectivity, easiness in product separation, short reaction time and the like.

Description

technical field [0001] The invention relates to a method for preparing oxazolidine-2,4-diketone heterocyclic compounds through the oxidative ring-closure reaction of alkyne amides catalyzed by Bronsted acid, which belongs to the technical field of organic chemical synthesis, especially the production of pharmaceutical intermediates synthesis technology. Background technique [0002] Oxazolidine-2,4-dione heterocyclic compounds are important structural units in organic synthesis and bioactive molecules, and have been reported to have various uses, such as antidiabetic, antibacterial, and anti-inflammatory activities. For example, ethosuximide and oxazolidine, which contain oxazolidine-2,4-dione structural fragments, have anticonvulsant effects. Therefore, people are very concerned about the synthesis of oxazolidine-2,4-dione heterocyclic compounds. [0003] In 1965, the Finkbeiner group reported the low-temperature reaction of phenyl isocyanate and ethyl glycolate to obtain...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D263/44C07D413/04
CPCC07D263/44C07D413/04
Inventor 何广科李渊姜栋杰苏仕轩
Owner NANJING TECH UNIV
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