Preparation of 2-pimelie kelone compound

Abstract

The invention discloses a method for preparing 2-cyclohexenone compound, which comprises the following steps: under the action of a metallic catalyst MYn.L, 1, 6-heptadiyne compound showed in formula (I) taken as a raw material is reacted in an ionic liquid at a temperature of between 0 and 150 DEG C; after the reaction liquid is treated, the 2-cyclohexenone compound showed in formula (II) is prepared; and at the same time, the ionic liquid fixed with the metallic catalyst can be recycled. The method has the advantages of simple and reliable operation, high yield and selectivity, repeated recycling and use of the noble metal catalyst, environmental protection, and the like. Because the cyclohexenone compound is a good raw material for synthesizing medicines, pesticides and chemical products, the method has wide industrial application prospect.

Description

(1) Technical field

[0001] The invention relates to a preparation method of 2-cyclohexenone compounds. (2) Background technology

[0002] Cyclohexenone compounds are very important intermediates in organic synthesis and are used in the fields of medicine, pesticide and chemical industry. Although the synthetic method of multiple 2-cyclohexenone compounds is reported ((1) J.Heterocycl.chem.1972,9,741 at present; (2) J.Am.Chem.Soc.1976,98,4887 ; (3) J.Org.Chem.1977, 42, 1349; (4) Bull.Chem.Soc.Jap.1997, 79, 1879; (5) J.Org.Chem.1997, 62, 9323), but Due to the structural specificity of its functional derivatives, its synthesis is greatly restricted. For example, the synthesis of 4-substituted derivatives of 2-cyclohexenones needs to introduce substituents in advance before ring closure, and at least 4 ~5 steps of chemical reaction can be completed, and the synthesis of such compounds under alkaline conditions will be restricted if the starting material molecule has functional...

Examples

Embodiment 1

[0024] Embodiment 1: the preparation of 3-methyl-5,5-dimethyl carboxylate-2-cyclohexenone

[0025] Dimethyl 2,2-dipropargyl malonate (104.1mg, 0.5mmol), gold complex (AuNO 3 ·PPh 3 , 12.5mg, 0.025mmol), methanesulfonic acid (20μL, 0.25mmol), water (10μL, 0.5mmol) in methanol (1.0mL) and the ionic liquid [Bmim]BF 4 (1.0 mL), and the mixture was heated at 70°C for 3 hours to react. After the reaction was completed, the methanol in the reaction solution was removed, and the organic matter (5×2 mL) in the ionic liquid was extracted with ether, and the remaining liquid after the extraction was the ionic liquid with the catalyst fixed, to be reused. After neutralizing methanesulfonic acid in the ether extract with saturated sodium bicarbonate, the organic layer was dried over anhydrous sodium sulfate. Diethyl ether was evaporated by filtration, and the obtained crude product was separated and purified by silica gel plate chromatography (petroleum ether: ethyl acetate = 5:1) to ob...

Embodiment 2

[0026] Embodiment 2: 3-methyl-5, the preparation of 5-dimethylcarboxylate group-2-cyclohexenone

[0027] Operation is with reference to embodiment 1, but nitrous group consumption is (AuNO 3 ·PPh 3 , 5mg, 0.01mmol), to obtain 81mg of the target compound (yield 72%).

Embodiment 3

[0028] Embodiment 3: the preparation of 3-methyl-5,5-dimethyl carboxylate group-2-cyclohexenone

[0029] Operation is with reference to embodiment 1, but nitrous group consumption is (AuNO 3 ·PPh 3 , 2.5mg, 0.005mol), to obtain 73mg of the target compound (yield 65%).

(1) Technical field

[0001] The invention relates to a preparation method of 2-cyclohexenone compounds. (2) Background technology

[0002] Cyclohexenone compounds are very important intermediates in organic synthesis and are used in the fields of medicine, pesticide and chemical industry. Although the synthetic method of multiple 2-cyclohexenone compounds is reported ((1) J.Heterocycl.chem.1972,9,741 at present; (2) J.Am.Chem.Soc.1976,98,4887 ; (3) J.Org.Chem.1977, 42, 1349; (4) Bull.Chem.Soc.Jap.1997, 79, 1879; (5) J.Org.Chem.1997, 62, 9323), but Due to the structural specificity of its functional derivatives, its synthesis is greatly restricted. For example, the synthesis of 4-substituted derivatives of 2-cyclohexenones needs to introduce substituents in advance before ring closure, and at least 4 ~5 steps of chemical reaction can be completed, and the synthesis of such compounds under alkaline conditions will be restricted if the starting material molecule has functional...

Examples

Embodiment 1

[0024] Embodiment 1: the preparation of 3-methyl-5,5-dimethyl carboxylate-2-cyclohexenone

[0025] Dimethyl 2,2-dipropargyl malonate (104.1mg, 0.5mmol), gold complex (AuNO 3 ·PPh 3 , 12.5mg, 0.025mmol), methanesulfonic acid (20μL, 0.25mmol), water (10μL, 0.5mmol) in methanol (1.0mL) and the ionic liquid [Bmim]BF 4 (1.0 mL), and the mixture was heated at 70°C for 3 hours to react. After the reaction was completed, the methanol in the reaction solution was removed, and the organic matter (5×2 mL) in the ionic liquid was extracted with ether, and the remaining liquid after the extraction was the ionic liquid with the catalyst fixed, to be reused. After neutralizing methanesulfonic acid in the ether extract with saturated sodium bicarbonate, the organic layer was dried over anhydrous sodium sulfate. Diethyl ether was evaporated by filtration, and the obtained crude product was separated and purified by silica gel plate chromatography (petroleum ether: ethyl acetate = 5:1) to ob...

Embodiment 2

[0026] Embodiment 2: 3-methyl-5, the preparation of 5-dimethylcarboxylate group-2-cyclohexenone

[0027] Operation is with reference to embodiment 1, but nitrous group consumption is (AuNO 3 ·PPh 3 , 5mg, 0.01mmol), to obtain 81mg of the target compound (yield 72%).

Embodiment 3

[0028] Embodiment 3: the preparation of 3-methyl-5,5-dimethyl carboxylate group-2-cyclohexenone

[0029] Operation is with reference to embodiment 1, but nitrous group consumption is (AuNO 3 ·PPh 3 , 2.5mg, 0.005mol), to obtain 73mg of the target compound (yield 65%).

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