CS237742B1 - Process for preparing 4,4'-bis- (4,6-diphenyl-5-cyano-2-pyridyl) biphenyls - Google Patents

Abstract

The method for producing 4,4-bis-(4,6-diphenyl- -p-cyano-2-pyridyl)biphenyls of formula I according to the invention consists in reacting compounds of formula II xc6h4coc(cn) = chc6h4i (II), where X and X denote hydrogen or alkyl with 1 to 4 carbon atoms in the alkyl chain or phenyl, and 4,4-diacetylbiphenyl in the presence of condensing agents and a suitable oxidant, at elevated temperature in an organic solvent. The advantage of this method is the easy availability of the starting components, the substances obtained are potential scintillators and photostabilizers.

Description

(54) A method for producing 4,4'-bis- (4,6-diphenyl-5-cyano-2-pyridyl) biphenyls

The process for the preparation of the 4,4-bis- (4,6-diphenyl-p-cyano-2-pyridyl) biphenyls of the formula I according to the invention is characterized in that reacting compounds of formula II xc ₆ h ₄ coc (cn) = chc ₆ h ₄ i (II), when X and X are hydrogen or alkyl of 1 to 4 carbon atoms in the alkyl chain or feoyl, and 4,4-acetylbiphenyl the presence of condensing agents and a suitable oxidizing agent, from an elevated temperature in the organic solvent. The advantage of this method is the easy availability of the starting components, the obtained substances being potential acintillators and photostabilizers.

The invention relates to a process for the preparation of 4,4'-b '- (4,6-diphenyl-5-cyan-2-pyridyl) biphenyls of the general formula 1

4-XC _e H ₄ - NC - <

-YC ₆ H 4 (I) wherein X and Ϊ denote hydrogen or alkyl of 1 to 4 carbon atoms in the alkyl chain or phenyl.

The compound of formula I has not been described in the literature. The invention relates to a process for the preparation of these substances. It is an object of the invention to react the compounds of formula II

X0 ₆ H ₄ COC (CN) CHC ₆ H ₄ Y (II) with 4,4'-diecetylbiphenyl in the presence of condensation agents such as ammonium salts of carboxylic and mineral acids and a suitable oxidant such as air oxygen, alkali metal or ferricyanides of alkali metal at 50 to 200 ° C in an organic solvent such as ethanol or dimethylformamide.

An advantage of the process according to the invention for the preparation of the 4,4'-ble- (4,6-diphenyl-5-cyano-2-pyridyl) biphenyls is the easy availability of the starting components of formula II, i.e. unsaturated cyanketones.

In order to achieve a satisfactory conversion of the reaction components to the desired products of the formula I, an elevated temperature of 50 to 200 ° C and an adequate reaction time of β to 20 hours and an appropriate dosage of the components are necessary. Under these conditions, the compounds I usually crystallize from the reaction mixture and can be easily isolated and refined.

The preparation of 4,4‘-bie- (4,6-dienyl-5-cyano-2-pyrldyl) biphenyls according to the invention is illustrated in more detail by way of several examples.

He did

Process for preparing 4,4'-bie / 6- (4-biphenyl) -4-phenyl-5-cyano-2-pyridyl / biphenyl

A mixture of 0.62 g of benzylidene-4-phenylbenzoylacetoniltril, 0.24 g of 4,4 ' -diethylbiphenyl,

0.15 g of ammonium acetate, 5 ml of ethanol and 5 ml of diaethylformamide was heated to 150 ° C in the presence of atmospheric oxygen for 8 hours. During this time, a precipitate precipitated from the reaction mixture, which, after cooling to room temperature, was filtered off with suction, washed with water and ethanol. Recrystallization from dimethylformaaid gave 0.20 g of the first crop of the desired product, mp 335-337 ° C. Dilution of the mother liquors after crystallization by addition of 100 ml resulted in the precipitation of the non-product, which was aspirated, washed with water, air-dried and mixed with 0.18 g of bensylidene-4-phenylbenzoylacetonitrile, 0.04 g of ammonium acetate, 5 ml of ethanol and 5 ml of diaethylformamide. . The resulting mixture was heated to boiling under atmospheric oxygen for 16 hours. After cooling, the precipitate (20 g) was filtered off with suction, washed with water, ethanol and recrystallized from dimethelforaaid. A second crop of melting point 335-337 ° C was obtained.

Example 1 a d 2

Process for preparing 4,4'-ble (6-phenyl-5-cyano-4-tolyl-2-pyridyl) biphenyl

A mixture of 0.62 g of 4-methylbenzylidene-benzoylacetoniltrile, 0.2 g of 4,4'-acetylbiphenyl, 0.1 0.19 g of ammonium acetate, 2 [mu] l of dimethylformamide and 5 ml of ethanol was heated to 130 [deg.] C. under atmospheric oxygen. 16 hours. After cooling to room temperature, the precipitate formed was filtered off with suction, washed with water and ethanol and recrystallized from toluene. 0.30 g of the desired product was obtained, which was purified by chromatography on a 60 g silica gel column eluting with chloroform, m.p. 345-346 ° C.

Example 3

A process for the preparation of 4,4'-bis (4,6-diphenyl-5-cyano-2-pyridyl) biphenyl

A mixture of 1 g of benzylidene-xenoxyacetonitrile, 0.51 g of 4,4-diacetylbiphenyl, 0.32 g of ammonium acetate, 5 ml of dimethylformamide and 5 ml of atanol was heated at 160 ° C for 12 hours under atmospheric oxygen. After cooling to room temperature, the precipitate formed was filtered off with suction, washed with water and ethanol and recrystallized from dimethylformamide.

0.19 g of the expected product is obtained, m.p. 342-344 ° C.

Said 4,4 &apos; -bis- (4,6-diphenyl-5-cyano-2-pyridyl) -phenyls are potential plastic scintillators and photoatabilizers.

Claims (3)

PREFACE TO THE INVENTION 1. Process for the production of 4,4'-bis-(4,6-diphenyl-5-cyano-2-pyridyl)biphenyls 4-XC ₆ H ₄ ^nc -$2/a2/ 4-YCgH^ where X and Y denote hydrogen, alkyl with 1 to 4 carbon atoms in the alkyl chain is obtained by reacting compounds of general formula II XC,H,COC(CN) = CBCrH.Y of general formula 1 (I), or phenyl, phenyl(IX), where X and Y have the above meaning with 4,4'-diacetylbiphenyl, at a temperature of 50 to 200 °C in an organic solvent, such as protic and aprotic organic liquids containing 1 to 5 carbon atoms, by the action of a condensing agent of the type of ammonium salts of carboxylic and mineral acids and an oxidant, such as molecular oxygen, nitro compounds or alkali metal ferricyanides. 2. The method according to item 1, characterized in that ammonium acetate is preferably used as the condensing agent. 3. The method according to item 1, characterized in that atmospheric oxygen is used as the oxidising agent.