SU311906A1 - METHOD OF OBTAINING OXYMS OF CYCLIC a-CYANKETONES - Google Patents

Description

This invention relates to a process for the preparation of oximes of cyclic α-cyanketones (1-iso-i-throso-2-cyanocyclanes), which can be used to synthesize various derivatives of these compounds (diamines, keto acids, amino ketones, amino acids, etc.) with biological activity.

The literature describes the preparation of imines cyclic a-cyanketones by cyclization of a, sodinitriles according to the following scheme:

-Gi

Wr, CH - CN

The cyclization of dinitriles is carried out for several tens of hours in the presence of a 5-fold amount of sodium methylaniline in pure nitrogen. At the same time, during the reaction it is necessary to maintain a constant minimum concentration of a, b-dinitrile, otherwise the yield of the final product sharply decreases due to an increase in the products of intermolecular condensation.

There are no methods for the preparation of cyclic α-cyanketones OXYMES in the literature.

The aim of the invention is to develop a new, simple method for the production of oxime cyclic a-cyanketones with high yield.

The peculiarity of the proposed method is that the target product is obtained by treating 2-halogen-1-nitroso-1-acetyl cyclones with potassium cyanide in alcohol, for example, in methanol, preferably when heated to a temperature not higher than 70 ° C.

The process is conducted on the following s.cheme:

NOH

SNS

KCN, ROH

Lno

L-CCH2) n

- 2 / VGI

L- (CH2) p

where n is O, 1, 2.3, and so on.

It was found that dimeric 2-halogen-1-nitroso-1-acetylcyclanes under the action of a suspension of potassium cyanide in methanol at a temperature of 65-70 ° C are converted into oximes of the corresponding a-cyanocyclans with a 60-70% output. It is difficult or impossible to obtain these compounds by other methods due to the lack of convenient methods for the synthesis of a-cyancyclanones.

(0.0037 mol of 2-chloro-1-nitroso-1-acetylcyclohexane dimer per 0.65 g (0.01 mol of potassium cyanide and 15 ml of methanol. The reaction mixture is boiled for 6-8 hours. After cooling, the precipitated potassium chloride and unreacted potassium cyanide is filtered off. The solution for purification from the starting compound is passed through an aluminum oxide layer and the latter is washed with 10-15 ml of methanol. Methanol is distilled off, and the crystalline residue is recrystallized from chloroform-petroleum ether .Yes are obtained 0.68 g (66.7 %) 2-cyanocyclohexanone oxime with mp of 115-116 ° С (from a mixture of chl oroform - petroleum ether).

PC spectrum (chloroform): 3495, 3400, 1660 slg-1.

Found,%: C 60.72, 60.97; H 7.60, 7.39; N 20.21, 20.09.

CynioNsO.

Calculated,%: C 60.87; P 7.24; N 20.29.

P r and. M with p 2. Oxime 2-cyancyclopentane. According to the procedure described in Example 1, 2-cyancyclopentanone oxime is obtained by churning the dimeric 2-chloro-1-nitroso-1-acetylcyclopentane cleavage. In this case, from 1.7 g (0.0048 mol) of acetylcyclopentane 2-chloro-1-nitroso-1 dimer of acetylcyclopentane, 0.71 g (59.2%) of 2-cyanoclonentanone oxime with m.p. 126-127 ° C (from a mixture of chloroform - petroleum ether).

IR (chloroform): 3500, 3410, 1685-1673 C; I-1.

Paydeno,%: C 58.07; H 6.65; N 22.38, 22.83.

Calculated,%: C 58.06; H 6.45; N 22.58.

Subject invention

Claims (2)

1. A method of producing oximes of cyclic a-cyanketones, characterized in that 2-halogen-1-nitroso-1-acetylcyclan is treated with potassium cyanide in alcohol, such as methanol, by heating, followed by isolation of the target product by known techniques. 2. A method according to claim 1, characterized in that the heating is carried out to a temperature not higher than 70 ° C.