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Method for preparing single-configuration C-2-position-monosubstituted norbornene derivative

A technology of norbornene and C-2, which is applied in the field of preparing single-configuration C-2-position monosubstituted norbornene derivatives, can solve the problems of difficult preparation of exoisomers and difficult separation conditions, and achieve raw material The effect of easy availability and simple preparation process

Pending Publication Date: 2021-06-29
HEFEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Aiming at the deficiencies in the prior art, the present invention provides a method for preparing a high-purity single-configuration (can be external or internal) C-2-position monosubstituted norbornene derivatives, solving the problem of existing external Technical problems such as difficult preparation of isomers or difficult separation conditions

Method used

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  • Method for preparing single-configuration C-2-position-monosubstituted norbornene derivative
  • Method for preparing single-configuration C-2-position-monosubstituted norbornene derivative
  • Method for preparing single-configuration C-2-position-monosubstituted norbornene derivative

Examples

Experimental program
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Effect test

Embodiment 1

[0027] Example 1, Preparation and separation of exo / endo-5-norbornene-2-carboxylate tert-butyl ester

[0028] Add 5-norbornene-2-carboxylic acid (5.0 g, 36.2 mmol, its 1 H NMR spectrum shows that its exo / endo isomer molar ratio is about 19:81). Then add 5mL tert-butanol (4.0g, 54.3mmol) and 4-dimethylaminopyridine (0.4g, 3.6mmol), the above system is dissolved with 20mL dichloromethane, then add 15mL dichloromethane dissolved 1 -Ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (8.4g, 54.3mmol), stirred at room temperature for 36h. After the reaction was completed, the product was processed by extraction to obtain the mixed 5-norbornene-2 ​​tert-butyl carboxylate (NMR results showed that its exo / endo isomer ratio increased to 44:56). Then, the mixed solution of 5-norbornene-2-carboxylate tert-butyl 5-norbornene-2-carboxylate with exo / endo isomers as filler, ethyl acetate and sherwood oil as eluent, was separated by column chromatography , the exo-tert-butyl 5-norborn...

Embodiment 2

[0029] Example 2, Preparation and separation of exo / endo-5-norbornene-2-carboxylate isopropyl ester

[0030] Add 5-norbornene-2-carboxylic acid (5.0 g, 36.2 mmol, its 1The HNMR spectrum shows that its exo / endo molar ratio is about 20:80). Then add 4mL of isopropanol (3.3g, 54.3mmol) and N-hydroxysuccinimide (0.4g, 3.6mmol), with 18mL of dichloromethane to dissolve the above system, then add 15mL of dichloromethane dissolved in the system N,N'-dicyclohexylated carbodiimide (11.2g, 54.3mmol), stirred at room temperature for 36h. After the reaction was completed, the product was processed by extraction to obtain the mixed 5-norbornene-2-carboxylic acid isopropyl ester of exo / endo isomers (NMR results showed that its exo / endo isomer ratio improved to 49:51). Then, the isopropyl 5-norbornene-2-carboxylate mixed with exo / endo isomers was separated and purified by fractional distillation to obtain exo-5-norbornene- 2-Isopropyl carboxylate and endo-5-norbornene-2-carboxylate isopr...

Embodiment 3

[0031] Example 3, Preparation of exo / endo-5-norbornene-2-carboxylic acid pentafluorophenyl ester

[0032] Add 5-norbornene-2-carboxylic acid (5.0 g, 36.2 mmol, its 1 H NMR spectrum shows that its exo / endo ratio is about 23:77). Then add pentafluorophenol (10.0g, 54.3mmol) and 4-dimethylaminopyridine (0.4g, 3.6mmol), the above system is dissolved with 30mL of dichloromethane, then 1- Ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (8.4g, 54.3mmol), stirred at room temperature for 48h. After the reaction was completed, the product was processed by extraction to obtain the mixed 5-norbornene-2-carboxylic acid pentafluorophenyl ester of exo / endo isomers (NMR results showed that the ratio of exo / endo isomers improved to 57:43). Then, the mixed solution of 5-norbornene-2-carboxylate pentafluorophenyl ester of exo / endo isomer is carried out column chromatography with silica gel powder as filler, dichloromethane and sherwood oil as eluent Separation, the exo-pentafluorophe...

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Abstract

The invention discloses a method for preparing a single-configuration C-2-position-monosubstituted norbornene derivative. The method comprises the following steps of: firstly, preparing exo-isomer enriched exo-isomer mixed 5-norbornene-2-carboxylic ester by taking commercial exo-isomer / endoisomer mixed 5-norbornene-2-carboxylic acid and large-steric-hindrance monohydric alcohol as raw materials; separating 5-norbornene-2-carboxylate with a single configuration through common column chromatography separation or fractionation; and finally, preparing the C-2-position-monosubstituted norbornene derivative with the single configuration from the separated 5-norbornene-2-carboxylate with the single configuration. The raw materials used in the invention are easy to obtain, the preparation process is simple, and the C-2-position-monosubstituted norbornene derivative with high purity (greater than 98%) and single configuration can be obtained.

Description

technical field [0001] The present invention relates to a method for preparing single-configuration C-2 monosubstituted norbornene derivatives, more specifically, a 5- Preparation of mixed exo / endo isomer 5-norbornene-2-carboxylate by reaction of norbornene-2-carboxylic acid with bulky monoalcohol, in which exo isomer is enriched in this reaction step , and the 5-norbornene-2-carboxylate with mixed exo / endo isomers can be successfully separated by column chromatography or fractionation into a single configuration, and then separated from the single configuration of 5-norbornene-2-carboxylate Bornene-2-carboxylate to prepare single-configuration C-2 monosubstituted norbornene derivatives. Background technique [0002] Norbornene (bicyclo[2,2,1]hept-2-ene, Norbornene, NB) and its derivatives can undergo direct addition polymerization or ring-opening metathesis polymerization of olefin moieties due to their high reactivity ( ROMP) and its copolymerization with other monomers ...

Claims

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Application Information

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IPC IPC(8): C07C67/08C07C67/48C07C67/56C07C67/54C07C69/753C07C29/147C07C33/36C07C45/29C07C47/445C07C51/09C07C61/29
CPCC07C67/08C07C67/48C07C67/56C07C67/54C07C51/09C07C29/147C07C45/292C07B2200/07C07C2602/42C07C69/753C07C61/29C07C33/36C07C47/445
Inventor 魏海兵徐赫武成王子豪杨善中丁运生
Owner HEFEI UNIV OF TECH
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