RU2185361C1 - Method of synthesis of 1,2-dialkyl-1,2-diethylcyclo-propanes - Google Patents

Abstract

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to a method of synthesis of 1,2-dialkyl-1,2-diethylcyclopropanes of the general formula (I)

where R¹ and R² mean respectively: n-Pr, n-Pr; n-Bu, n-Bu; Me, n-C₅H₁₁ that can be used as a basic component of high-energy fuels, for synthesis of antiviral medicinal preparations, pesticides, low-molecular bioregulating agents. Method involves interaction of dialkylsubstituted acetylenes R¹-≡-R² with triethylaluminium (Et₃Al) and diiodomethane (CH₂I₂)) taken in the mole ratio = 10 : 40 : 20, respectively. Interaction reaction is carried out under normal conditions in hexane medium at stirring for 16-20 h followed by hydrolysis of reaction mass with hydrochloric acid solution. The yield of the end product is 63-84%. EFFECT: high regioselectivity and yields of indicated tetrasubstituted derivatives of cyclopropanes from disubstituted acetylenes. 1 tbl

Description

где R¹, R² = n-Pr, n-Pr; n-Bu, n-Bu; n-Am, Me.The invention relates to the field of organic chemistry, specifically to a method for producing 1,2-dialkyl-1,2-diethylcyclopropanes of the general formula (1):

where R ¹ , R ² = n-Pr, n-Pr; n-Bu, n-Bu; n-Am, Me.

 Stressed cyclic hydrocarbons and their derivatives can be used as a component of high-energy fuels, as well as for the production of antiviral drugs, pesticides, low molecular weight bioregulators.

Известный способ не позволяет получать 1,2-диалкил-1,2-диэтилциклопропаны.A known method (SD Koch, RM Kliss, DV Lopiekes, RJ Wineman, J. Org. Chem., 1961, V. 26, No. 9, P. 3122) for the production of tetra-substituted cyclopropanes by the reaction of tetra-substituted ethylenes with diiodomethane (CH ₂ I ₂ ) in the presence of zinc copper pair according to the scheme:

The known method does not allow to obtain 1,2-dialkyl-1,2-diethylcyclopropanes.

где R=алкил, арил; R'=Et, Buⁱ.A known method (K. Maruoka, Y. Fukatani, H. Yamamoto, J. Org. Chem., 1985, V. 50, P. 4412) for producing monoalkyl (aryl) substituted cyclopropanes by reacting α-olefins with diiodomethane (CH ₂ I ₂ ) in the presence of trialkylalanes (Et ₃ Al, Bu ⁱ ₃ Al) according to the scheme:

where R = alkyl, aryl; R '= Et, Bu ⁱ .

 The known method does not allow to obtain 1,1,2,2-tetraalkyl substituted cyclopropanes.

 A new method for producing 1,2-dialkyl-1,2-diethylcyclopropanes is proposed.

The inventive method comprises reacting a dialkyl substituted acetylenes (2-octynyl, 4-octynyl, decynyl-5) with triethylaluminum (Et _of A1) and diiodomethane (CH ₂ I _2), taken in the molar ratio 10: (30-50) :( 15 -25), respectively, mainly 10:40:20 at room temperature (23-25 ^o C) and atmospheric pressure in hexane with stirring for 16-20 hours, followed by hydrolysis of the reaction mass with a solution of Hcl. Get 1,2-dialkyl-1,2-diethylcyclopropanes 1 with a yield of 63-84%.

R¹, R² = H-Pr, H-Pr; H-Bu, H-Bu; H-Am, Me;
Использование в указанной реакции меньших количеств Еt_зАl и CH₂I₂ приводит к снижению выхода целевых продуктов 1. Использование в реакции больших количеств дииодметана приводит к преимущественному образованию побочных продуктов иодирования. При более высокой температуре (например, 60^oС) выход целевых продуктов не увеличивается, а при меньшей температуре (например, О^oС) снижается скорость реакции.

R ¹ , R ² = H-Pr, H-Pr; H-Bu, H-Bu; H-Am, Me;
Using this reaction lesser amounts _of Al and Et CH ₂ I ₂ reduces the yield of the desired product 1. The use of large amounts of diiodomethane reaction leads to preferential formation of byproducts iodination. At a higher temperature (for example, 60 ^o C) the yield of the target products does not increase, and at a lower temperature (for example, O ^o C) the reaction rate decreases.

 Without triethylaluminum and diiodomethane, the reaction does not occur. In the absence of hexane, oligomerization products of disubstituted acetylene are formed.

 Without triethylaluminum and diiodomethane, the reaction does not occur. In the absence of hexane, oligomerization products of disubstituted acetylene are formed.

Significant differences of the proposed method from the known:
1. In the known method, olefins are used, while the proposed one uses disubstituted acetylenes (RC-CR).
The advantages of the proposed method:
1. In contrast to the known methods, the proposed one allows to obtain 1,2-dialkyl-1,2-diethylcyclopropanes 1 from disubstituted acetylenes with high regioselectivity and yields.

 The method is illustrated by examples.

EXAMPLE 1. In a glass reactor with a volume of 100 ml, immersed in an ice bath and mounted on a magnetic stirrer, in an atmosphere of inert gas, 50 ml of hexane, 10 mmol of decin-5, 40 mmol of Et ₃ Al and 20 mmol of CH ₂ I ₂ are loaded, stirred 18 h at room temperature (23-25 ^o C). The reaction mass is hydrolyzed with a solution of HCl, the organic layer is separated from the aqueous. 1,2-Dibutyl-1,2-diethylcyclopropane was isolated from the organic layer in 76% yield.

Спектр ЯМР¹³С (δ, м.д.): 14,21 (С1), 23,28 (С2), 24,26 (С3), 30,76 (С4), 30,04 (С5), 24,20 (С6), 29,23 (С7), 11,18 (С8). М⁺210.Spectral characteristics of 1,2-dibutyl-1,2-diethylcyclopropane:

¹³ C NMR spectrum (δ, ppm): 14.21 (C1), 23.28 (C2), 24.26 (C3), 30.76 (C4), 30.04 (C5), 24, 20 (C6), 29.23 (C7), 11.18 (C8). M ⁺ 210.

 Other examples confirming the method are given in table. 1.

All experiments were carried out at room temperature (23-25 ^o C). Hexane in an amount of 50 ml was used as a solvent.

Claims (1)

The method of obtaining 1,2-dialkyl-1,2-diethylcyclopropanes of the General formula

where R ¹ , R ² = n-Pr, n-Pr; n-Bu, n-Bu; Me, nC ₅ H ₁₁ ,
characterized in that the terminal acetylenes of the formula R ¹ -≡-R ² interact with triethylaluminum (Et ₃ Al) and diiodomethane (CH ₂ I ₂ ) in a molar ratio of R ¹ -≡-R ² : Et ₃ Al: CH ₂ I ₂ , equal to 10: 40: 20, under normal conditions in the presence of hexane with stirring for 16-20 hours, followed by hydrolysis of the reaction mass with a solution of hydrochloric acid.

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