Method for preparing multi-substituted cyclopentadiene and substituted indene

A cyclopentadiene and multi-substituted technology is applied in the field of synthesis of multi-substituted cyclopentadiene and substituted indene, which can solve problems such as poor selectivity of target products, and achieve the effects of increased ratio, high conversion rate and improved controllability.

Inactive Publication Date: 2011-03-30
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When water is only used as a reagent for active hydrogen atoms, the proportion of by-products with extracyclic double bonds in the product is relatively high, that is, the selectivity of the target product is poor.

Method used

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  • Method for preparing multi-substituted cyclopentadiene and substituted indene
  • Method for preparing multi-substituted cyclopentadiene and substituted indene
  • Method for preparing multi-substituted cyclopentadiene and substituted indene

Examples

Experimental program
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Effect test

Embodiment 1

[0037] Example 1 Preparation of 1-methyl-3-n-butylcyclopentadiene

[0038] Put the fully dried 250 ml three-necked flask into a stirring magnet, place it in an oil bath, vacuum, and flush with nitrogen, repeated three times. Add 20 ml of dry tetrahydrofuran that has been dewatered and deoxygenated, add 2.7 g of magnesium, and start stirring. A solution of n-butyl bromide in tetrahydrofuran (13.7 g of n-butyl bromide, 25 ml of tetrahydrofuran) is added dropwise, and the rate of dropping is preferably such that the reaction system slightly boils. After the dripping, the reaction system was refluxed for 1 hour in an oil bath at 80°C. The oil bath was changed to an ice water bath, the reaction system was cooled to 0°C, and 9.6 g methylcyclopentenone / 50 ml tetrahydrofuran was slowly added dropwise. After the addition is complete, stir at room temperature overnight. 3.2 g of anhydrous methanol was slowly added dropwise at room temperature. After the addition is complete, change the...

Embodiment 2

[0039] Example 2 Preparation of 1-methyl-3-n-butylcyclopentadiene

[0040] The implementation process is the same as in Example 1. The difference is that the reagent containing active hydrogen atoms is 4.6 grams of absolute ethanol.

Embodiment 3

[0041] Example 3 Preparation of 1,2,3,4,5-pentamethylcyclopentadiene

[0042] The fully dried 250 ml three-necked flask is placed in a stirring magnet, placed in an ice bath, vacuumed and flushed with nitrogen, repeated three times. Add 23 mL of Grignard reagent (methylmagnesium chloride, 22% tetrahydrofuran solution) and start stirring. 9.4 g of tetramethylcyclopentenone / 50 ml of tetrahydrofuran was slowly added dropwise. After the addition is complete, stir at room temperature overnight. 1.2 g of deionized water was slowly added dropwise at room temperature. After the addition is complete, change the ice water bath to an oil bath, reflux for 1.5 hours, cool, treat with dilute hydrochloric acid, separate the oil phase, and extract the water phase twice with 10 ml of ether. Combine the organic phases. Dry with anhydrous sodium sulfate, filter, and remove the solvent with a rotary evaporator.

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Abstract

The invention relates to a method for synthesizing multi-substituted cyclopentadiene and substituted indene. The method comprises the following steps of: reacting (substituted) cyclopentenone or indanone with a Grignard reagent; and then carrying out hydrolysis reaction treated with an active hydrogen atom-containing reagent. Through the method, multi-substituted cyclopentenone and substituted indene can be widely prepared. The active hydrogen atom-containing reagent is water, alcohol or phenol. Because of the improvement of the active hydrogen atom-containing reagent, the ratio of double bond products in a ring is greatly improved and the reaction controllability is greatly enhanced.

Description

Technical field [0001] The invention relates to a method for synthesizing polysubstituted cyclopentadiene and substituted indene, and belongs to the field of organic synthesis. technical background [0002] Cyclopentadiene or substituted derivatives of compounds with a cyclopentadiene ring structure, such as indene, tetrahydroindene, fluorene, etc., are one of the important ligands in organic synthesis. After this ligand forms a compound with a transition metal atom, it can be widely used in the field of catalysis. In particular, the metallocene compounds and single metallocene compounds formed with the fourth subgroup metals (titanium, zirconium, hafnium) can catalyze the polymerization of olefins in the presence of a co-catalyst, and the performance of the resulting polymer is much better than that of traditional catalysts. Polymerization product. At the same time, this metallocene catalyst has a high degree of controllability, and can balance the electronic effect and stereo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C13/15C07C13/465C07C1/20
Inventor 王伟郑刚
Owner CHINA PETROLEUM & CHEM CORP
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