Patent GB-597612-A (GB)
Title: Colour photography
IPC: G03C1/18
Filed: 1945-08-23
Abstract: Cyanine dyes of the general formula <FORM:0597612/IV/1> wherein R and R1 each represent H or alkyl or aryl groups or together represent the atoms necessary to complete a hydrogenated ring system R2 and R3 are alkyl groups, X is an acid group, Y is S or Se, and Z represents the atoms necessary to complete a heterocyclic ring are prepared by condensing quaternary ammonium salts of thiazoles or selenazoles containing the substituted methylene dioxy ring as part of the nucleus with any of the known cyanine dye intermediates.  R and R1 may be methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, decyl, phenyl, naphthyl, anthranyl, cyclopentylidene or cyclohexylidene and Z may complete an indolenine, thiazole, benzthiazole or benzselenazole ring, which may be substituted by alkyl, alkoxy, phenyl, naphthyl, anthranyl, alicyclic, dioxyalkyl or dioxycycloalkyl substituents.  Z may complete isopropylidenedioxy-, methylenedioxy-, dimethyl-, cyclopentylidenedioxy-, or cyclohexylidenedioxy-benzthiazole or benzselenazole rings or methylphenyl- or diphenyl-thiazole or p  selenazole rings.  3 : 31-Diethyl-5 : 6 : 51 : 61-diisopropylidenedioxybenzthiacarbocyanine iodide is prepared by refluxing together 2-methyl-5 : 6-isopropylidenedioxybenzthiazole ethyl p - toluenesulphonate and ethyl orthoformate in pyridine, and adding aqueous potassium iodide solution.  3 : 31-Diethyl-5 : 6 : 51 : 61-diisopropylidenedioxybenzselenacarbocyanine iodide, 3 : 31-diethyl-5 : 6 : 51 : 61-dicyclohexylidenedioxybenzthiacarbocyanine iodide, 3 : 31 - diethyl - 5 : 6 : 51 : 61-dimethylenedioxybenzthiacarbocyanine iodide, and 3 : 31-diethyl-5 : 6 : 51 : 61-dicyclopentylidenedioxybenzthiacarbocyanine iodide are similarly prepared.  3 : 31-Diethyl-5 : 6 - methylenedioxy - 51 : 61-dimethylbenzselenabenzthiacarbocyanine iodide is prepared by refluxing together in pyridine containing triethylamine 2 - (b  - acetanilidovinyl) - 5 : 6 - methylenedioxybenzselenazole ethiodide and 2-methyl-5 : 6-dimethylbenzthiazole ethyl p - toluenesulphonate, and adding aqueous potassium iodide to an alcohol solution of the precipitated dye.  3 : 31-Diethyl-5 : 6-methylenedioxy-41-phenyl-51 -methylbenzselenathiazolocarbocyanine iodide, 3 : 31 -diethyl-5 : 6-methylenedioxy-51 : 61-cyclohexylidenedioxybenzthiacarbocyanine iodide, 3 : 31-diethyl-5 : 6-methylenedioxy - 51 : 61-cyclohexylidenedioxybenzselenzbenzthiacarbocyanine iodide, 3 : 31-diethyl-5 : 6-methylenedioxy-41 : 51-diphenylbenzthiathiazolocarbocyanine iodide, 3 : 31-diethyl-5 : 6 -cyclohexylidenedioxy-61 : 71-benzbenzthiacarbocyanine iodide, and 3 : 31-di-ethyl - 5 : 6 - cyclohexylidenedioxy - 51 : 61 - di - methoxybenzthiacarbocyanine iodide are similarly prepared. Alkylidenedioxybenzenes and cycloalkylidenedioxybenzenes are prepared by reacting catechol with an aliphatic aldehyde or ketone or a cyclic ketone.  Isopropylidenedioxybenzene is prepared by dissolving catechol in hot anhydrous acetone and treating with excess phosphorus pentoxide.  Cyclohexylidenedioxybenzene and cyclopentylidenedioxybenzene are similarly prepared.  2 - Brom - 4 : 5 - isopropylidenedioxybenzene is prepared by adding bromine to a carbon disulphide solution of isopropylidenedioxybenzene.  2 - Bromo - 4 : 5 - cyclohexylidenedioxybenzene and 2 - bromo - 4 : 5 - cyclopentylidenedioxybenzene are similarly prepared.  1 - Nitro - 2 - bromo - 4 : 5 - isopropylidenedioxybenzene is prepared by nitrating 2-bromo-4 : 5-isopropylidenedioxybenzene with nitric acid. Bis-(1-nitro-4 : 5-isopropylidenedioxybenzene)-2 : 21-disulphide is prepared by treating a boiling ethyl alcohol solution of 1-nitro-2-bromo-4 : 5-isopropylidenedioxybenzene with a fused mixture of sodium sulphide and sulphur.  Bis-(1-nitro-4 : 5-isopropylidenedioxybenzene)-2 : 21-diselenide is similarly prepared.  Bis-(1-nitro - 4 : 5 - cyclohexylidenedioxybenzene) - 2 : 21 - disulphide and bis-(1-nitro-4 : 5-cyclopentylidenedioxybenze) - 2 : 21 - disulphide are prepared by treating a boiling ethyl alcohol solution of 1 : 2-dinitro - 4 : 5 - cyclohexylidenedioxybenzene or of 1 : 2 - dinitro - 4 : 5 - cyclopentylidenedioxy - benzene with a fused mixture of sodium sulphide and sulphur.  1 : 2-Dinitro-4 : 5 -isopropylidenedioxybenzene is prepared by treating isopropylidenedioxybenzene with a mixture of glacial acetic and fuming nitric acids.  1 : 2-Dinitro-4 : 5-cyclohexylidenedioxybenzene, 1 : 2-dinitro-4 : 5-cyclopentylidenedioxybenzene and 1 : 2-dinitro-4 : 5-methylenedioxybenzene are prepared similarly.  2-Methyl-5 : 6-isopropylidenedioxybenzthiazole is prepared by heating together bis-(1-nitro-4 : 5-isopropylidenedioxybenzene) - 2 : 21 - disulphide, acetic anhydride, glacial acetic acid and zinc.  The ethyl p-toluenesulphonate is prepared by heating with ethyl p-toluenesulphonate.  2-Methyl - 5 : 6 - cyclohexylidenedioxybenzthiazole, 2-methyl-5 : 6-cyclopentylidenedioxybenzthiazole, 2-methyl-5 : 6-isopropylidenedioxybenzselenazole, 2-methyl-5 : 6 - methylenedioxybenzthiazole and the corresponding ethyl p-toluenesulphonates are similarly prepared.  Bis - (1 - nitro - 4 : 5 - methylenedioxybenzene) - 2 : 21-disulphide is prepared by treating 4 : 5-dinitromethylenedioxybenzene with an alcoholic solution of sodium sulphide and sulphur.  2 - (b  - Acetanilidovinyl) - 5 : 6 - methylenedioxy - benzselenazole ethiodide is prepared by refluxing together a mixture of 2-methyl-5 : 6-methylenedioxybenzselenazole ethiodide, diphenylformamidine and acetic anhydride. 2-(b -Acetanilidovinyl) - 5 : 6 - methylenedioxybenzthiazole ethiodide and 2-(b -acetanilidovinyl)-5 : 6-cyclohexylidenedioxybenzthiazole ethiodide are similarly prepared. Specifications 458,400, 464,398, 465,823, [all in Group XX], 468,946, 479,838, [Group XX], 483,000 and 484,698 are referred to.