GB702247A - Oxonol dyes and photographic silver halide emulsions containing them - Google Patents

Abstract

N-Thiocarbo-n-tetradecoxyglycine is prepared by adding powdered potassium hydroxide to a solution of tetradecanol in carbon disulphide, adding the dried product to methanol, adding ethyl bromide, warming, diluting with water, refluxing the product with glycine, KOH, ethanol, and water, and acidifying. The corresponding ethyl, isopropyl, n-butyl, n- and tertamyl, n-hexyl, n-heptyl, n-octyl, n-decyl, n-dodecyl, n-hexadecyl; and g -phenyl-n-propyl compounds are similarly prepared. N-Dithiocarbo-n-octoxyglycine is prepared by shaking together glycine, carbon disulphide, and aqueous KOH, adding an ethanol solution of n-octylamine and heating, adding water, and acidifying. N-Dithiocarbo-n-dodecoxyglycine is similarly prepared. 2-Ethylthio-5-thiazolone is prepared by heating together N-dithiocarbethoxyglycine and acetic anhydride. 2-n-Octylthio-4-ethoxymethylene-5-thiazolone is prepared by heating together N-dithiocarbo-n-octoxyglycine, acetic anhydride, and ethyl orthoformate.ALSO:Oxonol dyes of the general formula <FORM:0702247/IV (c)/1> wherein R is alkyl, L a methine group, and Q represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing 5 or 6 atoms in the heterocyclic ring, are prepared by condensing a 2-alkylthio-5-thiazolone of the general formula <FORM:0702247/IV (c)/2> with a 4-ethoxymethylene compound of the general formula <FORM:0702247/IV (c)/3> wherein R2 is H or alkyl. The reaction may be effected in the presence of a basic condensing agent (e.g. triethylamine), with or without an inert solvent, and preferably with heating. [4-(2-Benzylthio-5-thiazolone)] [4-(2-phenyl-5-oxazolone)]-methine-oxonol is prepared by heating together 2-benzylthio-5-thiazolone, 4-ethoxymethylene-2-phenyl-5-oxazolone, ethanol, and triethylamine, diluting with water, and acidifying. [4-(2-n-Octylthio-5-thiazolone)] [4-(2-phenyl-5-oxazolone)]-methineoxonol, [4-(2-n-Octylthio-5-thiazolone)] [4-(2-acetamino-5-thiazolone)]-methineoxonol, and [4-(2-ethylthio-5-thiazolone)] [4-(2-n-octylthio-5-thiazolone)]-methylmethineoxonol are similarly prepared. [4-(2-Ethylthio-5-thiazolone)] [4-(2-n-tetradecylthio-5-thiazolone)]-methineoxonol is prepared by heating together N-dithiocarbo-n-tetradecoxyglycine, acetic anhydride, and ethyl orthoformate, removing volatile liquids under vacuum, adding 2-ethylthio-5-thiazolone, ethanol and triethylamine, heating, diluting with water, and acidifying. [4-(2-Ethylthio-5-thiazolone)] [4-(2-n-octylthio-5-thiazolone)]-methineoxonol and [4-(3-ethylthio-5-thiazolone)] [4-(2-n-dodecylthio-5-thiazolone)]-methineoxonol are similarly prepared. The preparation of bis-4-(2-ethylthio-5-thiazolone)-methineoxonol and bis-4-(2-benzylthio-5-thiazolone)-methineoxonol also is referred to. Specifications 689,025 and 700,734 are referred to.