Patent GB-562675-A (GB)
Title: Improvements in or relating to dyestuff intermediates
IPC: G03C7/327
Filed: 1941-10-31
Abstract: Polymeric dyestuff intermediates, useful in colour photography and also in coating or moulding compositions and viscose dopes, are produced by reacting, in a solvent medium, an aldehyde or ketone, or substance reacting as such, with a pyrazolone compound containing an unsubstituted intracyclic methylene group and an amino residue; the amino residue may be a primary or secondary amino, amido or sulphonamido group.  About one molar equivalent of aldehyde or ketone, or a small excess, is employed per mol. of pyrazolone compound.  The aldehyde or ketone is preferably a lower aliphatic one, e.g. formaldehyde, acetaldehyde, acetone, methyl ethyl ketone or diethyl ketone; other specified aldehydes are propionaldehyde, n - butyraldehyde, isobutyraldehyde, n - heptaldehyde, aldol, glyoxal, 2-ethylhexanol, benzaldehyde, cinnamaldehyde, o-nitrobenzaldehyde, phenylacetaldehyde, mesityl oxide, cyclohexanone, cyclopentanone, acetophenone and benzophenone; aldehydes containing carboxylic or sulphuric acid solubilising groups, e.g. glyoxylic and phthaldehydic acids, may be employed; aldehyde- or ketone-reacting substances are methylolamides and methylolamines, e.g. dimethylolurea, methylolurea, dimethyloladipamide, trimethylolmelamine, dimethylolguanidine, methyllauramide and trimethylolnitromethane.  Specified amino - pyrazolone compounds are 1-m-aminophenyl-3-methyl-5-pyrazolone, 1 - p - aminophenyl - 3 - methyl - 5 - pyrazolone, s-bis[meta(3-methyl-5-pyrazolone-1-yl)phenyl] urea and s-bis[meta(3-methyl-5-pyrazolone-1-yl)phenyl]adipamide.  The solvent medium may be aqueous, assisted, if necessary, with a water miscible organic solvent.  For colour photographic purposes, condensation is stopped before alkali-insolubility is reached. The polymeric dyestuffs may be dispersed in a colloid layer to form a photographic element which layer may contain light-sensitive silver salts.  The colour images are developed by aromatic amino colour-developing agents or by treatment to form azo dyes.  In examples, 1 - meta - aminophenyl - 3 - methyl - 5 - pyrazolone, dissolved in aqueous sodium hydroxide, is reacted with (I) formaldehyde, (II) acetaldehyde, (IV) benzaldehyde-o-sulphuric acid, (V) dimethylolurea, and (VIII) benzaldehyde-o-sodium sulphonate; s-bis[meta(3-methyl-5-pyrazolone - 1 - yl)phenyl]urea is reacted with (III) acetone, (VI) trimethylnitromethane, and (VII) benzaldehyde-o-sodium-sulphonate. The products are incorporated in silver halide emulsions and colour images developed with aromatic amino colour-developing agents or aryl hydrazines.  The products of examples (I), (II) and (VIII) give magenta images with p-aminodiethylaniline. Specifications 467,087, [Group XX], and 551,120 are referred to.  The Specification as open to inspection under Sect. 91 describes also the production of polymeric dye intermediates by reaction of similar aldehydes or ketones with acylacetarylides and exemplifies the production of intermediates by the reaction of bis-acetoacet benzidide with dimethylformamide; bis-acetoacet - p - phenylendiamine with benzaldehyde - o - sodium - sulphonate; acetoacetsulphanilide with benzaldehyde - o - sodium - sulphonate; and (p - amino - benzoyl) acetanilide with dimethylolurea.  The intermediates are incorporated in silver halide emulsions and the exposed images colour developed with p-aminodiethylaniline to give yellow pictures.  This subject-matter does not appear in the Specification as accepted.