GB659128A - Improvements in the production of photographic dye images - Google Patents

Abstract

2-Naphthyl-J-acid is prepared by refluxing together b -naphthylamine, sodium metabisulphite, and water, adding J-acid, and continuing refluxing, adding more J-acid and continuing refluxing, filtering hot, extracting the press cake at 60-80 DEG C. with dilute sodium chloride solution and again filtering, agitating the press cake with a mixture of water and toluene, adding ammonium hydroxide solution until the aqueous phase is basic to phenolphthalein, separating the aqueous phase, re-extracting with toluene, diluting, adding sodium chloride solution, neutralizing with acetic acid, decolorizing, treating with concentrated hydrochloric acid and washing, and purifying by forming the pyridine salt. The Specification as open to inspection under Sect. 91 comprises also the preparation of the ethyl urethane of b -naphthyl-J-acid by adding sodium hydroxide solution to a suspension of 2-naphthyl-J-acid in water, treating with ethyl chlorocarbonate, adding further quantities of sodium hydroxide and ethyl chlorocarbonate, filtering, dissolving in water, and treating with a salt solution. The butyl and methyl urethanes are similarly prepared. The hexadecyl urethane of 2-naphthyl-J-acid is prepared by dissolving the pure dry pyridine salt of 2-naphthyl-J-acid in a hot mixture of dry dimethylformamide and benzene, cooling, adding hexadecyl chlorocarbonate, and then adding pyridine. The urethane is obtained finally as the lithium salt. The dodecyl and octadecyl urethanes are similarly prepared. A brominated derivative of the hexadecyl urethane of 2-naphthyl-J-acid is prepared by refluxing together the lithium salt of the hexadecyl urethane of 2-naphthyl-J-acid, acetic anhydride, glacial acetic acid, and sodium acetate, cooling, and adding bromine dissolved in glacial acetic acid. This subject-matter does not appear in the Specification as accepted.