Patent GB-714276-A (GB)
Title: Improvements in or relating to methine dyestuffs and the sensitising of photographicemulsions therewith
Inventor: KENDALL JOHN DAVID
IPC: C09B23/01
Filed: 1951-12-12
Abstract: 2 - (b  - Methyl:b  - methoxyvinyl) - benzthiazole ethyl-methosulphate is prepared by fusing together 2 - acetylmethylene - 3 - ethyl - 2 : 3-dihydrobenzthiazole and dimethyl sulphate.  2 - (b  - methyl:b  - methoxyvinyl) - 3 : 3 - dimethylindoline methyl-methosulphate is similarly prepared.ALSO:Dyes of the general formula: <FORM:0714276/IV(c)/1> wherein R1 and R3 are alkyl, aralkyl or hydroxyalkyl groups, R2 is an alkyl, aralkyl, or aryl group, R4 is H or an alkyl, aralkyl, or aryl group, a, and b are each O or 1 X is an oxygen or sulphur atom, and D1 and D2 are each the residue of a 5- or 6-membered heterocyclic nitrogen nucleus of the type used in cyanine dyes are prepared by heating with more than one equivalent of a base dye of the general formula: <FORM:0714276/IV(c)/2> wherein R5 is an aralkyl group and Y an acid radicle. I-(3-Ethyldihydro benzthiozolylidene) -2 - Keto-3-[3-ethyl-4-Keto-5-(3'-ethyldihydro-benzthiazolylidene -ethylidene)-tetrahydrothiazolidene]-propene is prepared by refluxing together 3-ethyl - 4 - keto-5-[(3-ethyldihydrobenzthiazoly-lidene) - ethylidene] - b '-ethyl-7-methoxythiazolinothia carbocyanine methosulphate and pyridine. I-(3-Ethyldihydrobenzthiazolylidene)2-keto-3-[3 ethyl-4 - keto - 5 - (I - methyldihydroquinolylidene)tetrahydrothiazolyidene]-propane is prepared by refluxing together 3-ethyl-4-keto-5-(methyldihydroquinolylidene) -3'-ethyl-7-ethoxythiazolinothiacarbocyanine iodide, etherol, and sodium hydroxide.  The preparation of a number of other such dyes is described.  3-Ethyl-4-keto-5-[(3-ethyldihydrobenzthiazolylidene) - ethylidene] -3'-ethyl-7-methoxthiazolinothiacarbocyanine methosulphate is prepared by heating together 2-(b -methyl:b -methoxyvinyl)-benzthiazole ethyl-methosulphate and 2-methylthio-5-(3-ethyldihydrobenzthiazolylidene 2) - ethylidenethiazolone-4 ethylmethosulphate in ethanol and triethylamine.  3-Ethyl - 4 - keto - 5 - (3 - methyldihydroquinazolylidene-4-)- 3' - methyl - 7 - methoxythiazolinothiacarbocyanine methosulphate, 3 - ethyl - 4 - keto - L-[(3 - ethyl - 4:5 - benzdihydrobenzthiazolylidene) - ethylidene] - 3' - methyl - 7 - ethoxythiazolinothia carbocyanine methochloride, 3 - methyl - 4 - keto - 5 - (3 - methyldihydrobenzthiazolylidene)-1'-methyl-7 - methoxythiazolinoindocarbocyanine methosulphate, 3 - methyl - 4 - keto-5-](1:3:3-trimethyldihydroindolylidene) -ethylidene]-3'-methyl-7-ethoxythiazolinothiacarbocyanine chloride, and 3-methyl-4-keto - 5 - [(3-methyldihydrobenzthiazolylidene)-isopropylidene] - 3' - methyl - 7 - methoxythiazolinothiacarbocyanine methosulphate are similarly prepared.  3-Ethyl-4-keto-5 - (3-ethyl-5:6-methylenedioxydihydrobenzthiazolylidene) - ethylidene)3 - ethyl-7-ethoxythiazolinothiacarbocyanine bromide is prepared by fusing together 3-ethyl-5-(3-ethyl-5:6-methylenedioxydihydrobenzthiazolylidene-2) -ethylidenerhodanine, 2-acetylmethylene-3-ethyl-2:3-dihydrobenzthiazole, and ethyl p-toluensulphonate, adding ethanol and triethylamine and refluxing, and finally pouring the reaction mixture into aqueous KBr solution. 3-Ethyl-4-keto-5-(1-methyldihydroquinolylidene-2) - 3' - ethyl-7-ethoxythiazolinothiacarbocyanine iodide, 3-ethyl-4-keto-5-((1-ethyldihydroquinolylidene-2) - ethylidene) - 3'-ethyl-7-ethoxythiazolinothiacarbocyanine iodide, 3-ethyl-4-keto-5-[(3-ethyldihydrobenzselenazolylidene) -ethylidene]-3' -ethyl-7-ethoxythiazolinothiacarbocyanine iodide, 3-methyl - 4 - keto-5-[(3-methyldihydrobenzoxazolylidene)-ethylidene] - 3'-ethyl-7-methoxyoxazolinothiacarbocyanine ethiodide, 3 - methyl - 4 - keto-5-(3-methyldihydrobenzthiazolylidene) - 3' - methyl - 7 - methoxythiazolinothiacarbocyanine p - toluenesulphonate, and 3-ethyl-4-keto-5-[(3-b -phenylethyldihydrobenzthiazolylidene) - ethylidene]-3'-methyl-7-methoxythiazolinothiacarbocyanine bromide are similarly prepared. 2-Methylthio-5-(3-ethyldihydrobenzthiazolylidene-2) -ethylidenethiazolone-4 ethyl-methosulphate is prepared by fusing together 3-ethyl-5-(3-ethyldihydrobenzthiazolylidene-2) - ethylidene-rhodanine and dimethyl sulphate. 2-Methylthio-5-(3-methyldihydroquinazolylidene-4)-thiazolone-4 ethyl-methosulphate, 2-methylthio-5-(3-ethyl-4:5-benzdihydrobenzthiazolyidene - 2) - ethyldene-thiazolone-4 ethylmethosulphate, 2 - methylthio-5-(3-methyldihydrobenzthiazolylidene-2)-thiazolone-4 methyl-methosulphate, 2-methylthio-5-(1 : 3 : 3-trimethyldihydroindolylidene-2) - ethylidene - thiazolone-4 methylmethosulphate, and 2-methylthio-5-(3-methyldihydrobenzthiazolyidene - 2) - isopropylidene - thiazolone-4 methyl-methosulphate are similarly prepared.  Specification 646,137 is referred to.  According to the Provisional Specification, the dyes may have the general formula <FORM:0714276/IV(c)/3> wherein c is 1.