GB355693A - Manufacture of intermediates and dyes from heterocyclic nitrogen compounds - Google Patents

Abstract

Intermediates for polymethine dyes are obtained by condensing, in equimolecular proportions, heterocyclic nitrogen compounds containing reactive methyl groups or external reactive methylene groups with compounds of the general formula X = (CH)2n + 1 Y, where X is a substituted imino group and Y an arylamino group. Polymethine dyes are obtained by using two molecular proportions of the heterocyclic nitrogen compounds, or by condensing the intermediate products with a molecular proportion of a heterocyclic nitrogen compound as defined above or of a cyclic compound which contains an intracyclic reactive methylene group (e.g. a pyrazolone) or which reacts tautomerically as though such a group were present (e.g. an indole not substituted in the b -position). The dyes may be used for sensitizing photographic emulsions to light of long wavelength. In examples (1) 5 - anilino - 1 - phenylimino - D 2 : 4 - pentadiene hydrochloride is condensed with 1 : 3 : 3-trimethyl-2-methyleneindoline (2 mols.) in the presence of acetic anhydride; the product dyes tannined cotton bright green shades, and when applied in aqueous alcoholic solution to a photographic plate sensitizes the latter in the region of 750-900 m m ; (2) b -anilinoacroleinanil is condensed with 2 : 3 : 3-trimethylindolenine methiodide or with 2-methyl-benzthiazole ethiodide in equimolecular proportions, and the products are further condensed with molecular proportions of 2-methylbenzthiazole ethiodide or 2 : 3 : 3-trimethylindolenine methiodide in the presence of acetic anhydride; the resulting dye dyes tannined cotton a bright greenish-blue; (3) the intermediate product from b -anilinoacroleinanil and 2 : 3 : 3-trimethylindolenine methiodide is further condensed with a -methylindole; the product dyes tannined cotton a lavender blue shade, and (4) 1 : 3 : 3-trimethyl-2-methyleneindoline is condensed with b -anilinoacroleinanil (molecular proportions) in the presence of acetic anhydride.