SU327144A1 - METHOD OF OBTAINING ARYL SUBSTITUTED SALTS OF CYCLOPROPENYLIA - Google Patents

Description

The invention relates to the field of the preparation of aryl-substituted cyclopropenyl salts, which are used in a number of organic syntheses using cyclopropenyl cations.

A known method for the preparation of aryl-substituted cyclopropenyl salts by reacting Tolan with phenyldiazo-acetonitrile followed by treating the pyrily derivative with boron trifluoride.

When this process is carried out, cyclopropenyl salts are obtained which cannot be used for further processes, for example, condensation, because all aryl substituents are directly linked to the core of cyclopropenyl.

The purpose of the invention is to obtain cyclopropenyl salts with a mobile metpleny group, which allows their use in condensation processes with various substituents.

According to the proposed method, the salts of cyclopropylphosphonium salts are treated with tertiary potassium butylate in dry ether in the presence of carbonyl compounds at a temperature of minus 5 - mipus 15 ° C, followed by isolation of the formed alkylidenecyclopyde and its treatment with perchloric acid.

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The reaction of the formation of phosphorus and its interaction with the carbonyl component is carried out, as already mentioned, upon cooling. The use of potassium 3reg-butylate in this method allows the carbonyl component to be introduced before the formation of phosphorane. To decompose the betaine intermediate, the ether (in which the initial reaction step is carried out) is replaced by tetrahydrofurap and the reaction mixture is boiled for 10-15 minutes. I get one killer idea, the oprope cycle is separated by chromatographing.

alumina (eluted with petroleum ether or hexane). Alkylidene cyclopropene is converted to the corresponding salt of cyclopropenyl by the action of perchloric acid on it in alcohol or ether. All the initial components of this reaction must be applied thoroughly cleaned and dehydrated. The process is carried out in an atmosphere of dry, oxygen-free nitrogen.

Example.

1,2-Diphenyl-3- (diphenylmethylene) -cyclopropenyl perchlorate.

To a suspension of 5.52 g (0.01 mol} of thoroughly crushed and dried diphenylcyclopropenylphosphonium dichloride in 200 ml of absolute ether cooled to -10 ° C, 1.7 g (0.01 mol g / e potassium potassium butyl acetate and 2.7 g (0.015 zloz of freshly distilled benzophenone. Almost immediately brown phosphorus is formed, which, reacting with benzophenone, produces dark yellow ether-insoluble betaine. After one hour and a half stir, stop cooling, distill the ether and add to a residue of 20-25 ml dry of tetrahydrofuran, injected in a reaction mixture of 15-20 l. The cooled reaction mixture is chromatographed on an alumina column and the final product washed out with hexane.

The alkylidenecyclopropene obtained is converted into the corresponding cyclopropenyl salt by the action of chloric acid on it in ether. The yield of 1.9 g (41%), so pl. 219 ° C, white needles from the stock. Similarly, cyclropenylidenephosphorane with benzaldehyde, thiophene-2-aldehyde, and L-methyl-2-formylbenzene-imidazole, the corresponding diclopropenyl salts were obtained with horosol yields. All the compounds obtained are identified as elementary :,

analysis and infrared spectroscopy.

Subject invention

A process for the preparation of aryl-substituted cyclopropenyl salts, characterized in that

In order to obtain salts with a mobile methyl group, cycloprophenylphosphonium salts are treated with tertiary potassium butyl in dry ether in the presence of carbonyl compounds at a temperature of minus 5 - minus

15 ° C, followed by separation of the resulting alkylidene cyclopropene and its treatment with perchloric acid.