Patent GB-438603-A (GB)
Title: Manufacture of carbocyanine dyestuffs
IPC: C09B23/06
Filed: 1934-05-16
Abstract: Carbocyanine dyes are prepared by condensing an indoline compound containing in a -position to the nitrogen atom a reactive methylene group wherein one hydrogen atom is replaced by the aldehyde group, with a quaternary salt of a heterocyclic nitrogen compound containing in a - or g -position to the nitrogen a reactive methyl group. Instead of the quaternary salt there may be used in this reaction the corresponding heterocyclic nitrogen compound and condensation carried out in presence of a condensing agent yielding a hydrohalogen acid. The products are suitable for sensitizing photographic silver halide emulsions, particularly ammonia emulsions.  In examples p 1.3.3-trimethylindoline-2-methylene - o  - aldehyde is condensed with 1.3.3.-trimethyl-2-methyleneindoline in presence of phosphorus oxychloride (dyes tannin-mordanted cotton bluish-red) 2-methylbenzthiazole ethiodide, (bluish red on wool and tannin-mordanted cotton), 2.5.6-trimethylbenzthiazole ethiodide (bordeaux-red shades on wool and tannin-mordanted cotton), 2-methyl-5.6-dimethoxybenzthiazole ethiodide (violet-red on wool and tannin-mordanted cotton), 6-dimethylamino-2-methylbenzthiazole ethiodide (currant shades on wool and tannin-mordanted cotton), 4.5-benzo-2-methylbenzthiazole ethiodide (violet-red on wool and tannin-mordanted cotton), quinaldine ethiodide (violet on wool) and lepidine ethiodide (light-blue on wool and tannin-mordanted cotton), pyridine being employed as a diluent in each case. Reference is also made to the use of quaternary salts of quinaldine and lepidine having methyl, methoxy ethoxy, dialkylamino substituents in the respective benzene nuclei, and of indolines containing higher alkyl groups than methyl or nitro, amino, alkyl, alkoxy substituents in the benzene ring, or containing a naphthalene nucleus.  The indoline-aldehydes used as starting materials are prepared by the process described in Specification 438,278.  Samples have been furnished under Sect. 2 (5) of products prepared as follows:--(1) 1.3.3-trimethylindoline-2-methylene-o -aldehyde is condensed with 1.3.3-trimethyl-5-methoxy-2-methylene - indoline in presence of phosphorus oxychloride (bluish-red on tanninmordanted cotton); (2) 1.3.3-trimethyl-5-methoxyindoline - 2 - methylene - o  - aldehyde is condensed with 1.3.3-trimethyl-5-methoxy-2-methyleneindoline in presence of phosphorus oxychloride (violet on tannin-mordanted cotton) (3) 1.3.3 - trimethyl - 5 - methoxyindoline-2 - methylene - o - aldehyde is condensed with 5 - methoxy - 2 - methylbenzselenazole ethiodide in pyridine (violet on wool and tannin-mordanted cotton); (4) 1.3.3-trimethylindoline - 2 - methylene - o  - aldehyde is condensed with 2.5.6 - trimethylbenzoxazole ethiodide in pyridine (yellowish-red on wool and tannin-mordanted cotton); (5) 1.3.3.5-tetramethyl - 2 - methyleneindoline - o  - aldehyde is condensed with 6-methoxy-2-methylbenzoxazole ethiodide in pyridine (red on wool and tannin-mordanted cotton).  The Specification as open to inspection under Sect. 91 comprises a further example wherein 1.3.3.5.6-pentamethylindoline-2-methylene - o  - aldehyde is condensed with 2.5.6-trimethylbenzthiazole ethiodide (violet-red on wool and tannin-mordanted cotton).  This subject-matter does not appear in the Specification as accepted.