Patent GB-434234-A (GB)
Title: Manufacture of unsymmetrical pentacarbocyanine dyestuffs
IPC: C09B23/08
Filed: 1934-06-04
Abstract: Unsymmetrical pentacarbocyanine dyes are prepared by condensing to a tetramethine dye in the presence of an alkaline condensing agent equimolar proportions of a heterocyclic nitrogen base containing a reactive methyl group and a propene compound of the general formula <FORM:0434234/IV/1> (wherein R<1> stands for hydrogen or alkyl, R<2> for aryl and X for an acid radical), or a corresponding propene compound wherein one or more of the hydrogen atoms of the trimethine chain are replaced by an alkyl group or groups, and then condensing the tetramethine dye so obtained, in presence of an alkaline condensing agent, with an equivalent proportion of a quaternary ammonium salt of a heterocyclic nitrogen base containing a reactive methyl group and different from the base whose quaternary ammonium salt is used for making the tetramethine compound. Alkaline condensing agents suitable for both steps of the process are primary, secondary and tertiary amines such as methylamine, diethylamine, trimethylamine, triethylamine, piperidine, pyridine, ethanolamines, sodium ethylate, and in the case of the intermediate condensation, these agents are preferably used in amounts which do not exceed the equivalent of the base used (save where the condensing agent is also a diluent for the reaction). The dyes obtained are assigned the general formula <FORM:0434234/IV/2> wherein Y and Z stand for S, Se or--CH=CH--, R<1>, R<2>, R<3>, R<4> stand for hydrogen, alkyl, aryl or R<1> R<2> and R<3> R<4> together stand for unsubstituted or substituted phenylene, naphthylene or other polynuclear arylene groups (e.g. anthracene or acenaphthene); suitable substituents are alkyl, aryl, alkoxy, carbethoxy, thioalkyl, selenoalkyl, substituted or unsubstituted amino; Y and Z or R<1>, R<2> and R<3>, R<4> differ from one another; R<5>, R<6> stand for alkyl and X for an inorganic or organic acid radicle.  They are of use in sensitizing photographic silver halide emulsions (cf. Specification 434,235, [Group XX].  In examples: (1) 2-methylbenzthiazole ethiodide is condensed with a -phenylamido-g -phenylimidopropene hydrochloride in alcoholic piperidine and the resulting intermediate with 2.5.6-trimethylbenzselenazole ethiodide in alcoholic diethylamine; (2) 2-methyl - 5.6 - dimethoxybenzthiazole ethiodide is condensed with a -phenylamino-g -phenyliminopropene hydrochloride in alcoholic triethanolamine and the intermediate product so obtained is condensed with 2.4-dimethylthiazole ethiodide in alcoholic diethylamine; (3) 2-methyl - a  - naphthothiazole ethiodide is condensed with a -phenylamino-g -phenyliminopropene hydrochloride in alcoholic diethylamine-and the resulting intermediate with 2-methyl benzthiazole ethiodide in alcoholic diethylamine or with 2.4 - dimethyl - 5 - carbethoxythiazole ethiodide in alcoholic trimethylamine; (4) 2-methylbenzselenazole ethiodide is condensed with a  - phenylamino - g  - phenyliminopropene hydrochloride in alcoholic triethanolamine and the resulting intermediate with 2.4-dimethylthiazole ethiodide in alcoholic sodium ethylate; (5) 5-methoxy-2-methylbenzselenazole ethiodide is condensed with a -phenylamino-g -phenyliminopropene hydrochloride in alcoholic triethanolamine (or pyridine) and the resulting intermediate with p - toluquinaldine ethiodide in alcoholic triethanolamine or with 2-methyl-4-phenylthiazole ethiodide in alcoholic diethylamine or similarly with 4.6-dimethylquinoline methiodide; (6) lepidine methiodide is condensed with a -phenylamino-g -phenyliminopropene hydrochloride in alcoholic triethanolamine (or diethylamine) and the resulting intermediate with 2-methylbenzthiazole ethiodide or with 2.4-dimethylthiazole methiodide in alcoholic diethylamine; (7) 2-methylbenzthiazole ethiodide is condensed with a  - phenylamino - g - phenylimino - b  - methyl - propene hydrochloride (prepared analogously to a -phenylamino-g -phenyliminopropene hydrochloride from the correspondingly substituted propargylaldehyde acetal) in alcoholic piperidine and the resulting intermediate with 2-methyl-a -napththothiazole ethiodide in pyridine or with lepidine methiodide in alcoholic diethylamine; (8) 2-methylbenzselenazole ethiodide is condensed with a -phenylamino-g -phenylimino-b -methylpropene hydrochloride in diethylamine and the resulting intermediate with 2-methyl-5.6-ethylenedioxybenzselenazole ethiodide (cf. example 9 of Specification 418,745, [Group XX]) in alcoholic diethylamine; (9) 2-methyl-6-ethoxybenzthiazole ethiodide is condensed with a -phenylamino-g -phenyliminopropene hydrochloride in alcoholic piperidine and the resulting product condensed with 2-methyl-6.7-naphthobenzthiazole ethiodide, or 2.7-dimethyl-4.5-benzobenzthiazole ethiodide (prepared from 1-acetylamino-3-methylnaphthalene by conversion to the thioacetyl derivative with phosphorus pentasulphide followed by oxidation by means of potassium ferricyanide and reaction with ethyliodide), or 2-methyl-tetrahydro-a -naphthothiazole ethiodide in alcoholic diethylamine; (10) 2 - methyl - 5 - diethylaminobenzthiazole ethiodide is condensed with a -phenylamino-g -phenyliminopropene hydrochloride in alcoholic triethanolamine and the resulting intermediate with 2 - methyl - 6.7 - benzobenzthiazole diethylsulphate in alcoholic diethylamine; (11) 2-methyl-5.6-diethoxybenzthiazole ethiodide is condensed with a -phenylamino-g -phenyliminopropene hydrochloride in alcoholic trimethylamine and the resulting intermediate with 2.4-dimethylthiazole ethiodide in alcoholic diethylamine; (12) quinaldine ethiodide is condensed with a -phenylamino-g -phenyliminopropene hydrochloride in pyridine (or alcoholic triethanolamine) and the product condensed with 2.4-dimethyl-5-carboethoxythiazole methiodide (derived from thioacetamide and a -chloracetic acid ethyl ester by Hantzsch's method) in alcoholic diethylamine or with 2-methyl - 6 - acetylaminobenzthiazole diethylsulphate in alcoholic triethanolamine; (13) 2 - methyl - 5 - ethoxybenzselenazole ethiodide is condensed with a -phenylamino-g -phenyliminopropene hydrochloride or with the corresponding b -methyl derivative thereof in pyridine and the resulting intermediates are condensed with 2.4-dimethylthiazole methiodide in alcoholic di- or triethylamine, or the firstnamed intermediate is condensed with 2.6-dimethyl - 5 - chlorobenzthiazole ethiodide in alcoholic sodium ethylate; (14) 2.5.6-trimethylbenzthiazole ethiodide is condensed with x - phenylamino - g  - phenylimino - b  - methylpropene hydrochloride in alcoholic triethanolamine and the resulting intermediate with 2-methyl-4-phenylthiazole methiodide or with p-toluquinaldine ethiodide in alcoholic diethylamine; (15) 2.5.6 - trimethylbenzthiazole ethiodide is condensed with a -phenylamino-g -phenyliminopropene hydrochloride in alcoholic piperidine and the resulting intermediate with 2-methyl-5-chlorbenzselenazole ethiodide; (16) 2-methyl-p-tolylthiazole ethiodide is condensed with a  - phenylamino - g  - phenyliminopropene hydrochloride in alcoholic piperidine and the resulting intermediate with 2-methylacenaphthenethiazole ethiodide in alcoholic piperidine. Specification 355,693 also is referred to.  The Specification as open to inspection under Sect. 91 also relates to the formation of tetramethine dye intermediates by condensing equimolar proportions of a heterocyclic nitrogen base having a reactive methyl group, and a propene compound as specified, and also contains a reference to the dyes of the above general where R<1> R<2> and R<3> R<4> stand for chrysene or fluorene.  In an additional example p-toluquinaldine ethiodide is condensed with a -phenylamino-e -phenyliminopropene hydrochloride in presence of sodium acetate and acetic anhydride and the product further condensed with 2-methylbenzthiazole in presence of diethylamine.  This subject-matter does not appear in the Specification as accepted.