Patent GB-477983-A (GB)
Title: Improvements in or relating to the production of photographic sensitising compounds
IPC: C09B23/02
Filed: 1936-04-06
Abstract: Bases corresponding to the cyanine and carbocyanine dyes are made by heating in the presence of an acid binding agent a quinoline base having a reactive methyl group in the a - or g -position to the nitrogen atom with an alkyl quaternary salt of a heterocyclic nitrogen compound having a thioether, selenoether, aminovinyl or substituted aminovinyl group in the a -position to the nitrogen atom. Quinoline bases specified are quinaldine, lepidine, a - and b -naphthoquinaldines, a - and b -naphtholepidines and their alkyl, alkoxy, alkylthio and amino derivatives.  Heterocyclic nitrogen compounds specified are thiazoles, thiazolines, oxazoles, oxazolines, selenazoles, selenazolines, pyridines, quinolines, indolenines, diazines (cf. Specification 425,609), e.g. pyrimidines, thiodiazoles and quinazolines and polycyclic compounds such as benzthiazoles, naphthathiazoles and anthrathiazoles.  The bases may be converted into the corresponding dyestuffs by addition of an alkyl salt. The bases are sensitizers for silver halide photographic emulsions.  In examples, (1), (3), (10), (11), (15), (16) 1-methylthiolbenzthiazole methyl p-toluenesulphonate is condensed in pyridine with quinaldine, lepidine, 2 : 3-dimethylquinoline, 6-aminoquinaldine, 4-methyl- or 4-ethylthiolquinaldine (cf. Beilstein, 1899, Vol. 4, p. 313), (2) 2-methylthiolquinoline methyl-p-toluenesulphonate is condensed with quinaldine as above, (4), (20) 1-methylthiol-5 : 6-benzbenzthiazole methyl-p-toluenesulphonate is condensed as above with b -naphthoquinaldine and quinaldine, (5) 1-methylthiolbenzoxazole methyl-p-toluene sulphonate is condensed as above with quinaldine, (6) 1-o -acetanilidovinylbenzthiazole methiodide is condensed with quinaldine as before, (7), (8), (9) 1 : 3 : 3-trimethyl-2-o -acetanilidovinylindolenium iodide is condensed as above with quinaldine or with an excess of 6-ethoxyquinaldine, or 2 : 6-dimethylquinoline the excess of base acting as the acid binding substance, (12) 1-methylthiol-4 : 5-dimethoxybenzselenazole methyl-p-toluenesulphonate is condensed with quinaldine in presence of pyridine, (13) 1-methylthiol-4 : 5-methylenedioxybenzthiazole methyl-p-toluene sulphonate is condensed with quinaldine as in (12), (14) 1-methylthiol-4:5-dimethoxybenzthiazolemethyl-p-toluenesulphonate is condensed with quinaldine as above, (17), (18) 1-methylthiol-3 : 4-benzbenzthiazole methyl-p-toluene sulphonate is heated with 2 : 6-dimethylquinoline or quinaldine as above, (19) 1-ethylthiol-5 : 6-benzbenzthiazole ethyl-p-toluenesulphonate is condensed with quinaldine as above, (21) 1-ethylthiolbenzthiazole ethyl-p-toluenesulphonate is condensed with quinaldine in pyridine. A sample has been furnished under Sect. 2 (5) of the product obtained by condensing 1-methylselenomercaptobenzthiazole methyl p-toluene sulphonate with quinaldine in presence of pyridine.  Specification 456,362, [Group XX], also is referred to.  According to the Provisional Specification a heterocyclic nitrogen base having a reactive methyl group in the a  or g -position is condensed with a quaternary salt of a heterocyclic nitrogen compound having the reactive group in the a - or g -position to the nitrogen atom.