Ether bond breakage method for phenylalkyl ethers

A technology of phenyl alkyl ether and ether bond, which is applied in the field of intermediate synthesis of medicines and chemical raw materials, can solve the problems such as low yield of eugenol demethylation reaction, and achieve the effect of wide application range and high catalytic activity

Active Publication Date: 2017-06-20
JINGCHU UNIV OF TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

To this end, Arifin et al. developed the AlCl 3 -DMS method (Indon.J.Chem.2015,15,77), but the yield for eugenol demethylation is still very low (around 30%)
CN106278825A discloses a method for breaking ether bonds with aluminum triiodide-pyridine, which removes the methyl group of eugenol with a near quantitative yield, but because pyridine affects the aluminum triiodide by complexing with aluminum triiodide The oxophilicity of , so that this method can only be used for o-hydroxyphenyl alkyl ethers, but not for the ether bond cleavage of phenyl alkyl ethers without ortho-hydroxyls

Method used

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  • Ether bond breakage method for phenylalkyl ethers
  • Ether bond breakage method for phenylalkyl ethers
  • Ether bond breakage method for phenylalkyl ethers

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Embodiment 1 (eugenol demethylation)

[0035]

[0036] Add aluminum triiodide (2.247g), acetonitrile (40ml), DCC (0.618g) and eugenol (0.818g) respectively in a 100ml eggplant-shaped bottle, heat to 80°C, stop stirring after 18 hours of reaction, cool to After room temperature, add 2mol / L dilute hydrochloric acid (50ml) into the eggplant-shaped bottle to acidify, extract with ethyl acetate (50ml×3), combine the organic phases, wash with saturated sodium thiosulfate aqueous solution (10ml), and then wash with saturated Wash with brine (10ml), dry over anhydrous magnesium sulfate, filter, evaporate the filtrate to dryness with a rotary evaporator, and purify the residue by flash column chromatography (eluent: ethyl acetate / petroleum ether=1:4, volume ratio) , to obtain 0.721 g of 4-allyl catechol (white waxy solid, yield 96%).

[0037] 1 H NMR (400MHz, CDCl 3 )δ6.80(d, J=8Hz, 1H), 6.72(d, J=2Hz, 1H), 6.63(dd, J 1 =8Hz,J 2 =2Hz,1H),6.10(brs,2H),5.92(ddt,J 1 =17.2H...

Embodiment 2

[0039] Embodiment 2 (eugenol demethylation)

[0040] Add aluminum triiodide (2.252g), acetonitrile (40ml), N,N'-dicyclohexylcarbodiimide DCC (1.036g) and eugenol (0.818g) respectively in a 100ml eggplant-shaped bottle, and heat to 80°C, stop stirring after 18 hours of reaction, cool to room temperature, add 2mol / L dilute hydrochloric acid (50ml) into the eggplant-shaped bottle to acidify, extract with ethyl acetate (50ml×3), combine the organic phases, and first use thio Wash with saturated aqueous sodium sulfate (10ml), then with saturated brine (10ml), dry over anhydrous magnesium sulfate, filter, and evaporate the filtrate to dryness with a rotary evaporator, and the residue is subjected to flash column chromatography (eluent is ethyl acetate / petroleum ether=1:4, volume ratio) to obtain 0.723 g of 4-allyl catechol (white waxy solid, yield 96%).

Embodiment 3

[0041] Embodiment 3 (eugenol demethylation)

[0042] Add aluminum triiodide (2.247g), acetonitrile (40ml), DCC (1.549g) and eugenol (0.818g) respectively in a 100ml eggplant-shaped bottle, heat to 80 ° C, stop stirring after 18 hours of reaction, cool to After room temperature, add 2mol / L dilute hydrochloric acid (50ml) into the eggplant-shaped bottle to acidify, extract with ethyl acetate (50ml×3), combine the organic phases, wash with saturated aqueous sodium thiosulfate (10ml), and then wash with saturated Wash with brine (10ml), dry over anhydrous magnesium sulfate, filter, evaporate the filtrate to dryness with a rotary evaporator, and purify the residue by flash column chromatography (eluent: ethyl acetate / petroleum ether=1:4, volume ratio) , to obtain 0.684 g of 4-allyl catechol (white waxy solid, yield 91%).

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Abstract

The invention discloses an ether bond breakage method for phenylalkyl ethers. The method comprises the step: subjecting the phenylalkyl ethers to an ether bond breakage reaction at the temperature of -20 DEG C to reflux temperature in an organic solvent in the presence of aluminum triiodide and carbodiimide, so as to produce phenols and derivatives thereof. The method is moderate in conditions, simple and convenient in operation, high in yield and wide in applicable phenylalkyl ether range.

Description

technical field [0001] The invention relates to the technical field of intermediate synthesis of medicines and chemical raw materials, in particular to a method for breaking ether bonds of phenyl alkyl ethers. Background technique [0002] Dealkylation of phenyl alkyl ethers to phenol by ether bond scission reaction is a commonly used organic reaction. Ether bond cleavage can be carried out under the action of Bronsted acid or Lewis acid. Commonly used Bronsted acids include HCl, HBr and HI, etc. Commonly used Lewis acid BBr 3 and AlCl 3 Wait. When the substrate contains functional groups sensitive to acid and alkali, it will be more difficult to use these methods for demethylation. For example, the demethylation of eugenol by these methods can only obtain moderately low yields. [0003] To solve this problem, Lange developed the AlCl 3 -The method of tertiary amine, and successfully applied to the demethylation reaction (US3256336) of o-hydroxyanisoles such as vanillin....

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C37/00C07C39/19C07C39/21C07C39/08C07C45/65C07C47/565C07C253/30C07C255/53C07C51/377C07C65/03C07C67/317C07C69/84C07C231/12C07C233/18C07C201/12C07C205/44
CPCC07C37/00C07C45/65C07C51/377C07C67/317C07C201/12C07C231/12C07C253/30C07C39/19C07C39/21C07C39/08C07C47/565C07C255/53C07C65/03C07C69/84C07C233/18C07C205/44
Inventor 桑大永田娟
Owner JINGCHU UNIV OF TECH
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