Colour photographic materials and processes

N - (4 - n - dodecylphenyl) - N1 - (1 - [4 - nitrophenyl - 5 - pyrazolonyl - 3) pyromellitic diimide is obtained by reacting 1-(4-nitro-phenyl)-3 - amino - 5 - pyrazolone with N - (4 - n - dodecylphenyl) pyromellitic monoimide monoanhydride. 1 - (4 - nitrophenyl) - 3 - (a - sulphostearoylamino) - 5 - pyrazolone is obtained by reacting 1 - (4 - nitrophenyl) - 3 - amino - 5 - pyrazolone with a -sulphostearic acid monosodium salt. 4-(4n-Dodecylphenylaminocarbonyl) - N - [1 - (4 - nitrophenyl) - 5 - pyrazolonyl-3] phthalimide is obtained by reacting 4-(4-n-dodecylphenylaminocarbonyl) phthalic anhydride with 1-(4-nitrophenyl)-3-amino-5-pyrazolone. 1 - (4 - nitrophenyl) - 3 - (4 - n - dodecylanilino)-5-pyrazolone is obtained by reacting 1 - (4 - nitrophenyl) - 3 - amino - 5 - pyrazolone with 4-n-dodecylaniline in acetic acid. The sodium salt of the corresponding 3-sulpho anilino compound is prepared by reaction of the product with conc. sulphuric acid in the presence of Na+. 1-(2,4-dinitrophenyl) - 3 - heptadecyl - 5 - pyrazolone is obtained by reacting ethylstearoylacetate with 2,4-dinitrophenylhydrazine in acetic acid to give the corresponding hydrazone, followed by treatment with NaOH/ethanol. 1 - (2 - nitro - 4 - sulphophenyl) - 3 - heptadecyl - 4 - (4 - methoxy - phenylazo)-5-pyrazolone is obtained by reacting ethylstearoylacetate with 2-nitro-4-sulphophenyl hydrazine to give the corresponding hydrazone which is cyclized by treatment with NaOH/ethanol to 1-(2-nitro-4-sulphophenyl)-3-heptadecyl-5-pyrazolone, which compound is reacted with 4-methoxybenzene diazonium chloride to form the azo compound.