Patent GB-1335079-A (GB)
Title: Photographic materials containing fluorescent brightening agents
IPC: G03C1/815
Filed: 1971-04-19
Abstract: 1335079 4-Benzoxazolyl-4<SP>1</SP>-naphthotriazolylstilbene derivatives and intermediates therefor KODAK Ltd 19 April 1971 [3 April 1970] 25920/71 Headings C2C and C2P [Also in Divisions C4 and G2] (1) 4-[Benzoxazol-2-yl]-4<SP>1</SP>-[naphtho(1,2-d) triazol-2-yl]stilbene is prepared by adding diethyl p(benzoxazol-2-yl) benzylphosphonate to a slurry of sodium hydride in 1,2-dimethoxyethane and then adding 4-[naphtho(1,2-d)triazol-2-yl] benzaldehyde.  (2) Diethyl p-(benzoxazol-2-yl)benzylphosphonate is prepared by heating 2-(4-bromomethylphenyl)benzoxazole with triethyl phosphite. (3) 2-(4-Bromomethylphenyl)benzoxazole is prepared by heating a mixture of 2-(p-tolyl) benzoxazole, N-bromosuccinimide and benzoyl peroxide under reflux. (4) 4-[Naphtha(1,2-d)triazol-2-yl]benzaldehyde  is prepared by refluxing 2-(4-bromomethylphenyl)naphtho(1,2-d)triazole with a solution of hexamethylene tetramine in chloroform. The quaternary ammonium salt which had separated was then refluxed with 50% aqueous acetic acid and finally heated with hydrochloric acid. (5) 2-(4-Bromomethylphenyl) naphtho(1,2-d) triazole is prepared by heating a mixture of 2- (p-tolyl) naphtho (1,2-d) triazole, N-bromosuccinimide and benzoyl peroxide under reflux. 4-[Benzoxazol-2-yl]-3<SP>1</SP>-hydroxy-4<SP>1</SP>-[naphtho (1,2- d)triazol-2-yl]stilbene is prepared by heating diethyl p-(benzoxazol-2-yl)benzyl phosphonate to a slurry of sodium hydride in 1,2-dimethoxy ethane and then adding 3 - hydroxy - 4- [naphtho(1,2 - d)triazol - 2 - yl]benzaldehyde. 3 - Hydroxy - 4 - [naphtho(1,2-d)triazol-2-yl] benzaldehyde is prepared by the methods described for compounds (3) and (4) using 2-(2-acetoxy-4- methylphenyl)naphtho(1,2-d)triazole in place of 2-(p-tolyl)benzoxazole. 2-(2-Acetoxy-4-methyl- .phenyl)naphtho(1,2-d)triazole is prepared by warming 2-(2-hydroxy-4-methylphenyl)naph. tho(1,2-d)triazole with acetic acid and pyridine. 2 - (2 - Hydroxy - 4 - methylphenyl)naphtho(1,2-d) triazole is prepared by refluxing 1-(2-hydroxy-4- methylphenylazo)-2-naphthylamine with a copper sulphate pentahydrate solution in pyridine and then adding sodium sulphide. 1-(2- Hydroxy-4-methylphenylazo)-2-naphthylamine is prepared by suspending 4-amino-3-hydroxytoluene in a mixture of glacial acetic acid and ice in an atmosphere of nitrogen, diazotizing it with sodium nitrite, and adding the filtered diazonium salt to a suspension prepared by dissolving 2-naphthylamine in hot glacial acetic acid and rapidly cooling the suspension in ice. (6) 3<SP>1</SP> - Acetoxy - 4 - [benzoxazol - 2 - yl] - 4<SP>1</SP>- [naphtho(1,2-d)triazol-2-yl]stilbene is prepared by heating a suspension of 4-[benzoxazol-2-yl]-3<SP>1</SP>- hydroxy - 4<SP>1</SP> - [naphtho(1,2-d)triazol- 2 - yl] stilbene in pyridine and acetic anhydride and then allowing the suspension to stand. 4-[Benzoxazol - 2 - yl] - 3 - hydroxy - 4<SP>1</SP> - [naphtho(1,2-d) triazol-2-yl]stilbene and its intermediates are prepared by methods similar to those described for compounds (1) to (5) except for 2-(2- hydroxy - 4 - methylphenyl)benzoxazole. 2-(2- Hydroxy - 4 - methylphenyl)benzoxazole is prepared by adding a mixture of 2-hydroxy-4- methylbenzoic acid and o-aminophenol to polyphosphoric acid and heating. 3-Acetoxy-4- [benzoxazol - 2 - yl] - 4<SP>1</SP> - [naphtho(1,2-d)triazol-2- yl]stilbene is prepared by a method similar to that used for compound (6).