SU1082787A1 - Derivatives of 1,4-bis-(5-aryloxazolyl-2)-benzene as organic phosphors of blue-green luminescence - Google Patents

Abstract

1,4-bis derivatives

Description

31 138 g (1 mol) of 2,5-dimethylmercaptobeisol are mixed with 320 ml of water, 320 ml of duxane and 160 g of NaOH. The reaction mass is heated to 60 ° C and freon-22 is passed through at this temperature. The precipitate introduced into the NaF is filtered off. The oil is separated in a separatory funnel and used in further steps. The crude yield is 160 g (84%). Preparation of 1-difluoromethylsulfonyl-2, 5-dimethylbenzene. - Dissolve 188 g (1 mol) of 1-difto-methylsulfide-2,5-dimethylbenzene in 1200 ml of acetic acid. Then 300 ml of perhydrol are added and slowly heated to boiling. It is boiled for 10 hours and, after cooling, is poured into water. The precipitate is filtered off, washed with water and dried. The crude yield is 180 tons (82%). Preparation of difluoromethylsulfonylterephthalic acid To 220 g (1 mol) of 1-difluoromethylsulfonyl-2, 5-dimethylbenzene, 790 g (5 mol) of potassium permanganate (in portions) were added with heating in 1500 ml of water and vigorous stirring. After adding the total KMpO, the mixture is boiled for 3 hours. The unreacted KMpO is removed with sodium hydrosulfite (Na2SpO. In the hot state, the mixture is filtered and the filtrate is acidified with hydrochloric acid. The white precipitate is filtered off and washed with water and dried. Yield 145 g ( 52%). The product is purified by recrystallization from methanol. T. pl.261-263 Found: C 38.8; H 2.0; S 11.6 Calculated,%: C 38.6; H 2.1; S 11, Preparation of difluoromethylsulfonylterephthalic acid dichloride, 250 g (1 mol) of difluoromethyl sulfonylterephthalic acid are boiled in four times (by weight) from a thionyl chloride residue for 2 hours, an excess of thionyl is distilled off in a water jet of a jHoro pump, the residue is dissolved in benzene and used in further synthesis steps. Preparation of 1,4-bis-5-phenoxo-azolyl-2) -3- ( difluoromethylsulfonyl) -benzene. K. mixtures of solutions of 28 g (O, 1 mol) of difluoromethylsulfonyl terephthalic acid dichloride hydrate in 300 ml of benzol 74 and 34 g (0.2 mol) of hydrochloride and α-aminoacetophenone in 300 ml of water with vigorous stirring and room temperature at a temperature, a 10% soda solution is added dropwise to a weakly alkaline reaction to litmus. The precipitate formed is filtered off, washed with water and dried, and then dissolved in a tenfold (by weight) amount of concentrated sulfuric acid. The solution obtained is kept at room temperature for 2 hours and poured onto ice. The precipitation is filtered off, washed with water until neutral reaction to litmus and dried. Yield 35 g (73.2%). The product is purified by chromatography of its benzene solution on a continuous column with alumina. T. pl. 213-214 ° C. Found,%: C 62.5; H 3.1; N 6.0 Calculated,%: C 62.8; H 3.3; N 5, 9. , luminescence in toluene is 460 nm. The absolute quantum yield in toluene is 0.61. Example 2. Preparation of 1,4-bis-5- (4-anisyl) -oxazolyl-23-3-difluoromethylsulfonylbenzene. The reaction is carried out analogously to example 1, while taking 28 g (0.1 mol) of difluoromethylsulfonyl terephthalic acid dichloride and 40.4 g (0.2 mol) of methoxy-W-aminoacetophenone hydrochloride. The yield of the desired product is 41 g (74%). The product is purified by chromatography of its benzene solution on a continuous column with alumina. M.p. .205-206 ° С Found,%: С 63.7; H 3.6; N 5.3; F 7.1; S 5.9 Calculated,%: C 63.9; H 3.7; N 5.2; F 7.0; S 5.9. luminescence in toluene 485 nm. The absolute quantum yield in toluene is 0.73. PRI me R 3. Obtaining 1,4-bis- (5-Fensch1pxazolyl-2) -3-cyanobenzene. Preparation of 2,5-bis- (5-phenyloxazole 7-2) benzoic acid. To a suspension of 29 g (O, 1 mol) of 4- (5-fench1Oxazolyl-2) -phthalic anhydride and 17 g (0.1 mol) of y-aminoacetophenone hydrochloride in 500 ml of acetone with vigorous stirring and a temperature of 20-25c dropwise A 10% soda solution is added until slightly alkaline to litmus. The mixture is stirred for 1 hour, diluted with 800 ml of water, acidified with 10% hydrochloric acid solution, and the precipitated precipitate is filtered off with water and dried. Dried sulfur-white powder of 4- (5-phenyloxazolyl-2) -phthalic acid acylamide is dissolved at room temperature in a ten-fold (by weight) amount of concentrated sulfuric acid. The resulting dark brown solution is kept at room temperature for 2 hours and poured onto ice. The precipitate is filtered off, washed with water and dried. Yield 35.8 g (87.7%). The product is purified by double recrystallization from acetic acid. T. pl. 2U-215 ° C; Found: C 73.3; H 4.0; N 6.7 hell N 0 Calculated,%: C 73.5; H 3.9; N 6.9 Preparation of 2,5-bis- (5-phenyloxazolyl-2) -benzoic acid amide. 40.8 g (0.1 mol) of 2,5-bis- (5-phenyloxazolyl-2) -benzoic acid are boiled in 200 ml of thionyl chloride for 2 hours. Excess thionyl is distilled off under a water-jet vacuum and the residue is dissolved in 300 ml of benzene. Then, with stirring, the benzene solution of the acid chloride obtained is poured into 500 ml of a 10% ammonia solution. The precipitated amide precipitate is filtered off, washed with water, dried and used in further stages of the synthesis. Preparation of 1,4-bis- (5-phenoxoloxyl I-2) -3-cyanobenzol. To a solution of 40.7 g (0.1 mol) amber of 2,5-bis- (5-phenyloxazolyl-2) -benzoic acid in 200 ml of dry dimethylformamur (DMF) with vigorous stirring and a temperature of 0-5 ° C is added 260 ml of thionyl chloride. After addition of all thionyl, the mixture is slowly heated to 60 ° C and held for 3 hours. Then the reaction mixture is poured into cold water. The precipitate formed is filtered off, washed with water and dried. Yield 32 g (82%). The product is purified by chromatography of its benzene solution on a JONKON continuous action on alumina. T. pl. 233-234 ° C Found,%: C 77.3; H 4.0; N 10.6 Calculated,%: C 77.1; H 3.9; N 10.8 luminescence in toluene 440 nm. The absolute quantum yield in toluene is 0.61. Testing 1,4-bis- (5-aryloxazolyl-2) -benzene derivatives as organic phosphors. The luminescence spectra in toluene were measured, the absolute quantum yields were determined, and the photo stability of compounds of formula (1) was also studied. At the same time, similar measurements were made for the compound of formula (1). The luminescence spectra are measured on a setup consisting of a mirror ZMR-3 monochromator, a PMT-18 photomultiplier tube and an M-95 microsampmeter, the exciter is served by the SDNS-500 lamp, from the spectrum of which an excitation line of 365 nm is extracted. The absolute quantum yield is determined by the method of equal absorption. In order to determine the stability of compounds to the action of UV rays, their toluene solutions are irradiated with unfiltered light of a PRK-2 mercury quartz lamp (the distance from the lamp to the sample is 12 cm, the temperature of the illuminated field is 26 ° C). Photosensitivity is characterized by a change in the luminescence intensity of samples at the maximum of luminescence relative to the intensity of luminescence of unirradiated samples of the same phosphors, which is taken to be 100%. The luminescence constants and photosensitivity of the compounds are given in the table. As can be seen from the table, the compounds of formula (1) are effective organic phosphors. According to the intensity of luminescence in toluene solutions, they are 1.5–2 times greater than the known compound. In addition, the chemical compounds of formula (1) have significant photo-stability. So, after 7 hours of irradiating a KIM gesture with UV light (unfiltered light of the PRK-2 lamp), the intensity of their luminescence either does not change at all, or falls by 5-17%, while the luminescence intensity of the compound of formula (11) drops by half. The creation of a series of luminescent materials (fluorescent liquids 108278 7 for flaw detection, day fluorescent pigments and dyes, liquid and plastic scintillators) based on compounds of the formula (1) makes it possible to significantly improve the quality of the last.

gO2CHF2

UN,

Q, 73

83

485

0.61

440

95

0.41

415

50

Claims (1)

1,4-bis (5-arylox · zolyl-2) -benzene derivatives of formula Ar Ar where Ar is phenyl or 4-anisyl; X is difluoromethylsulfonyl; or Ar is phenyl, X is a cyano group, as organic phosphors of a blue-green glow. m 00 ! I87 78 7