Patent GB-646900-A (GB)
Title: Thiazolone cyanine dyes and the method of preparing the same
IPC: C09B23/04
Filed: 1948-08-06
Abstract: Substituted thioamides of the general formula <FORM:0646900/IV (b)/1> wherein A1 is the residue of a heterocyclic nucleus having 5 or 6 atoms in the heterocyclic ring, R2 is alkyl, allyl, aryl, or aralkyl, R3 is alkyl or aralkyl, and m is 1 or 2, are prepared by condensing a heterocyclic quaternary ammonium salt containing a reactive methyl group in the a - or g -position to the quaternary N atom with an alkyl, allyl, aryl, or aralkyl isothiocyanate in the presence of a base such as triethylamine or pyridine.  a -(3-Ethylbenzthiazolylidene)-thioacetanilide is prepared by heating together 2-methylbenzthiazole and ethyl p-toluenesulphonate, pouring the product into a solution of phenyl isothiocyanate in pyridine, and stirring and heating. a -(3-Methyl-6-methoxybenzthiazolylidene)-thioacetanilide is prepared by mixing together 2-methyl-6-methoxybenzthiazole methyl p-toluenesulphonate, methanol, phenyl isothiocyanate, and triethylamine, and allowing to stand.  a -(1-Ethyl-3 : 3 : 5-trimethylindolinylidene) - thioacetanilide, a  - (3 - ethylbenzthiazolylidene)-N-allylthioacetamide, a -(3-ethyl-5-methoxybenzselenazolylidene) - thioacetanilide, a  - (3 - ethyl - 4 : 5 - diphenyloxazolylidene) - thioacetanilide, a  - (3 - ethyl - 5 : 6 - dimethylbenzoxazolylidene) - thioacetanilide, a  - (3 - ethylbenzthiazolylidene)-thioacet-o-toluidide, a -(3-ethyl6 - methoxybenzthiazolylidene) - thioacet - a  - naphthalide, a  - (3 - ethylbenzthiazolylidene) - N - ethylthioacetamide, a  - (3 : 6 - dimethylbenzthiazolylidene) - thioacetanilide, a  - (3 - ethyl - 6 - methoxybenzthiazolylidene) - thioacet - b  - naphthalide, a  - (1 - methyl - 2 - quinolylidene) - thioacetanilide, a  - (3 - methylbenzselenazolylidene) - thioacetanilide, and a  - (3 - ethyl - 5 - methyl - 4 - phenylthiazolylidene) - thioacetanilide are similarly prepared. Specification 646,896 is referred to.ALSO:A thiazolone cyanine dye is prepared by heating a substituted thioamide of the general formula <FORM:0646900/IV (c)/1> wherein A1 is the residue of a heterocyclic nucleus having 5 or 6 carbon atoms in the heterocyclic ring, R2 is alkyl, allyl, aryl, or aralkyl, R3 is alkyl or aralkyl, and m is 1 or 2, with an a -halogen- or a  : a -dihalogen-acetic acid or with an a -halogenpropionic acid.  The reactants may be heated together in a bomb or sealed tube or may be refluxed or heated together with an alcohol or acetic acid or anhydride.  Numerous thioamides are specified.  Dyes are prepared by heating together: (1) a  - (3 - ethylbenzthiazolylidene) - thioacetanilide and bromacetic acid in n-butanol; (2) a  - (3 - methyl - 6 - methoxybenzthiazolylidene)-thioacetanilide and bromacetic acid in n-butanol; (3) a  - (1 - ethyl - 3 : 3 : 5 - trimethylindolinylidene)-thioacetanilide and bromacetic acid in n-butanol; (4) a -(3-ethylbenzthiazolylidene)-N-allylthioacetamide and chloracetic acid in n-butanol; (5) a -(3-ethyl-5-methoxybenzselenazolylidene) - thioacetanilide and bromacetic acid in n-butanol; (6) a -(3-ethylbenzthiazolylidene)-thioacet-o-toluidide and bromacetic acid in n-butanol; (7) a -(3-ethyl-6-methoxybenzthiazolylidene) - thioacet - a  - naphthalide and bromacetic acid in n-butanol; (8) a -(3-ethylbenzthiazolylidene) - N - ethylthioacetamide and bromacetic acid in acetic acid; (9) a  - (3 - ethyl - 6 - methoxybenzthiazolylidene)-thioacet-b -naphthalide and bromacetic acid in n-butanol; (10) a -(3 : 6-dimethylbenzthiazolylidene)-thioacetanilide and bromacetic acid in n-butanol; (11) a -(3-ethyl-5-methyl-4-phenylthiazolylidene)-thioacetanilide and bromacetic acid in acetic acid; (12) a -(3-methylbenzselenazolylidene) - thioacetanilide and bromacetic acid in n-butanol; (13) a -(1-methyl-2-quinolylidene) - thioacetanilide and bromacetic acid in n-butanol; (14) a -(3-ethylbenzthiazolylidene) - thioacetanilide and a  - chloropropionic acid in n-propanol; (15) a -(3-ethylbenzthiazolylidene)-thioacetanilide and dichloracetic acid in n-propanol; (16) a -(3-ethyl-4 : 5-diphenyloxazolylidene)-thioacetanilide and bromacetic acid in p acetic acid; and (17) a -(3-ethyl-5 : 6 - dimethylbenzoxazolylidene) - thioacetanilide and bromacetic acid in acetic acid.  The dyes may be converted to iodides, perchlorates, or thiocyanates. Specification 646,896 is referred to.