Patent GB-556266-A (GB)
Title: Improvements in and relating to polymethine dye intermediates and to the production of polymethine dyes
IPC: C09B23/10
Filed: 1941-09-26
Abstract: 556,266. Polymethine dyes and intermediates. KODAK, Ltd. Sept. 26, 1941, No. 12486. Convention date, Oct. 18, 1940. Samples furnished. [Class 2 (iii)] [Also in Group XX] A compound of the general formula of Fig. 1 where R represents an alkyl or aryl radical, R<SP>1</SP> represents an alkyl radical, X represents an acid radical, and Z the non-metallic atoms necessary to complete a 5- or 6- membered heterocyclic nucleus is prepared by condensing a #-alkoxyacrolein acetal with a cyclammonium quaternary salt containing a methyl group in the α-position to the nitrogen atom and employing as the reaction medium substantially anhydrous acetic acid not containing more than 1 per cent. of water. From 1 ¢ to 3 molecular proportions of acrolein acetal may be used for each molecular proportion of cyclammonium quaternary salt. The cyclammonium quaternary salt may be a quinoline, benzoxazole, naphthoxazole, benzthiazole, naphthathiazole, benzselenazole, or thiazoline derivative. The reaction medium may be glacial acetic acid and the quaternary salt an iodide. 2-(4-Ethoxy- #<SP>1</SP>:<SP>3</SP>-butadienyl)-benzthiazoleethiodide is prepared by reacting 2-methylbenzthiazole ethiodide and #-ethoxyacrolein diethyl acetal in glacial acetic acid. 2-(4-Ethoxy-#<SP>1</SP>:<SP>3</SP>-butadienyl)-benzoxazole ethiodide, 2-(4-etlaoxy-#<SP>1</SP>:<SP>3</SP>- butadienyl)-#-naphthathiazole ethiodide, 2-(4- ethoxy-#<SP>1</SP>:<SP>3</SP>-butadienyl)-α-naphthoxazole ethiodide, 2-(4-ethoxy-# <SP>1</SP>:<SP>3</SP>-butadienyl)-#-naphthoxazole ethiodide, 2-(4-ethoxy-#<SP>1</SP>:<SP>3</SP>-butadienyl)-quino line ethiodide, 2-(4-ethoxy-#<SP>1</SP>:<SP>3</SP>-butadienyl)-benzselenazole ethiodide, 2-(4-ethoxy- #<SP>1</SP>: <SP>3</SP>-butadienyl). thiazoline ethiodide, 2-(4-ethoxy-#<SP>1</SP>:<SP>3</SP>-butadienyl). benzthiazolepheniodide, and 2-(4-ethoxy-#<SP>1</SP>:<SP>3</SP>- butadienyl) 3:4 - - trimethylene benzthiazolium iodide are similarly prepared. Polymethine dyes are prepared by condensing a compound of the general formula shown in Fig. 1 with a cyclammonium alkyl quarternary salt containing a methyl group in the α or y position to the nitrogen atom. Pyridine or trialkylamines dissolved in acetic anhydride may be used as condensing agents. 3 : 3<SP>1</SP>- Diethylthiadicarbocyanine iodide is prepared by refluxing together 2 - (4 - ethoxy - # <SP>1</SP> : <SP>3</SP> - butadienyl) - benzthiazole ethiodide and 2 - methylbenzthiazole ethiodide in pyridine. 1<SP>1</SP>: 3- Diethyloxa - 2<SP>1</SP> - dicarbocyanine iodide is similarly prepared using as condensing agent acetic anhydride containing triethylamine. 1<SP>1</SP> : 3 - - Diethylthia - 2<SP>1</SP> dicarbocyanine iodide, 1<SP>1</SP> : 3 - diethylthia - 4<SP>1</SP> - dicarbocyanine iodide 3 : 3<SP>1</SP> - diethyl - 4 : 5 benzthiadicarbocyanine iodide, 3 : 3 - diethyl - 4 5 : 4<SP>1</SP>: 5<SP>1</SP> - dibenzthiadicarbocyanine iodide, 1 : : 1<SP>1</SP> - diethyl 2 : : 2<SP>1</SP>- dicarbocyanine iodide, 3 : 3<SP>1</SP> - diethyloxadi - carbocyanine iodide, 3 : 3<SP>1</SP> - . diethyloxathiadicarbonyanine isodide, 1<SP>1</SP> : 3 - diethyloxa - 4<SP>1</SP> - dicarbocyanine iodide, 3 3<SP>1</SP> - diethylselena - dicarbocyanine iodide, 3 : 3<SP>1</SP> - diethylselenathiadicarbocyanine iodide, 3 : 3<SP>1</SP>- diethyloxaselena dicarbocyanine iodide, and 3 - ethyl - 3<SP>1</SP> - methylthiathiazolino dicarbocyanine iodide are similarly prepared. Polymethine dyes may also be prepared by condensing the compounds of the general formula of Fig. 1 with a heterocyclic compound having a methylene group adjacent to a carbonyl group. 3 - - Ethyl - 5 - [(3 - - ethyl - 2 - benzthiazolyidene) - butenylidene] - rhodanine is prepared by condensing 2 - (4 - ethoxy - #<SP> 1</SP> : 3- butadienyl) - benzthiazole ethiodide with 3 - ethylrhodanine in the presence of triethylamine and acetic anhydride. The intermediate may also be condensed with 1 - phenyl - 3 - methyl - 5 -.pyrazolone or with 1 - ethyl - 3 - phenyl - 2 - thiohydantoin. Polymethine dyes may also be prepared by condensing the intermediates with primary or secondary aliphatic or aromatic amines. 2 - (4- Piper´dino - #<SP>1</SP> : <SP>3</SP> - butadienyl)- benzthiazole ethiodide is prepared by refluxing together 2 - (4 - ethoxy - #<SP>1</SP> : 3 - butadienyl)- benzthiazole ethiodide and piperidine in ethyl alcohol. The intermediate may also be condensed with aniline. Polymethine dyes may also be obtained by condensing the intermediates with N - alkyl or N - aryl pyrroles. Such dyes may be used as light-screening substances in the preparation of photographic elements, and are bleachable in alkaline developers. (3 - - Ethyl - 2 - benzthiazole) (1 - - heptyl - 2 : 5 - dimethyl - 3 - pyrrole) - tetramethinecyanine iodide is prepared by refluxing together 2 - (4 - ethoxy - #<SP>1</SP> : 3 - butadienyl) - benzthiazole ethiodide and 1 - heptyl - 2 : 5 - dimethylpyrrole in acetic anhydride. (3 - - Ethyl - 2 - benzoxazole) (1 - - heptyl - 2 : 5 - dimethyl - 3 pyrrole-, (3 - - ethyl - 2 - benzoxaozle) (1 - lauryl - 2 : : 5 - dimethyl 3 - - pyrrole) 3 - - ethyl - 2 - benzoxazole)- (1 - ethyl - 2 : : 5 - dimethyl - 3 - pyrrole)-, (1 - cetyl - 2 : 5 - dimethyl 3 - - pyrrole) 3 - - ethyl - 2 - benzoxazole)-, (1 ethyl - 2: 5 - dimethyl - 3 - pyrrole) - (3 - ethyl - 2 - α - naphthoxazole),- (3 - - ethyl - 2 - α - - naphthoxazole) - (1 lauryl - 2 : 5 - - dimethyl 3 - pyrrole)-, (1 - ethyl - 2 : 5 - dimethyl - 3 pyrrole) (1 - - ethyl - 2 - # - naphthoxazole)-, 1 - - ethyl - 2 5 - dimethyl - 3 pyrrole)- (1 - - ethyl 2 - quinoline)-, (3 - - ethyl - 2 - benzthia; zole)- (1 - ethyl - 2 : 5 - dimethyl - 3 pyrrole)-,. (3 - - ethyl - 2 - benzthiazole)- (2 : 5 dimethyl 1- phenyl 3 - - pyrrole)-, (1 - - ethyl - 2 : 5 - dimethyl- 3 - pyrrole) - (3 - - methyl - 2 thiazoline)-, and (3 - - ethyl - 2 - - benzselenazole) (1 - - ethyl - 2 : 5- dimethyl - 3 - pyrrole) tetramethine cyanines are similarly prepared. Samples have been furnished under Sect. 2 (5) of (a) 2<SP>1</SP> - (4 - methoxy - #<SP>1</SP> :<SP>3</SP> -butadienyl)- benzoxazole ethiodide (b) 2<SP>1</SP> - (4-piperidine - # <SP>1</SP>: <SP>3</SP> - butadienyl) - benzthiazole ethiodide: (c) 2<SP>1</SP> - (4 - anilino - #<SP>1</SP> : 3 - butadienyl) - benz -  thiazole ethiodide : and (d) 2<SP>1</SP> - (4 - dibutylamino - # <SP>1</SP> : <SP>3</SP> - butadienyl) - benzoxazole ethoper - chlorate. Specification 551,331 is referred to.