GB468375A - Improvements in the manufacture and production of partially hydrogenated compounds containing several nuclei - Google Patents

Abstract

Partially hydrogenated hydroxy compounds are manufactured by treating aromatic or heterocyclic monohydroxy compounds, containing at least two nuclei which are joined together directly and which may contain other substituents in addition to the hydroxy group, in alkaline solution with hydrogen under increased pressure, e.g. above 25 atmospheres, preferably at 100--250 atmospheres, in the presence of hydrogenation catalysts, preferably at elevated temperatures, e.g. 70--150 DEG C., whereby hydrogenation takes place in the nucleus not containing the hydroxy group, and in some cases also partially in the nucleus containing the hydroxy group. The process is applicable to the hydrogenation of monohydroxy compounds of the naphthalene series, e.g. a - and b -naphthol, hydroxynaphthoic acids and their amides, e.g. anilides, toluidides or xylidides, and similar hydroxy compounds of anthracene, phenanthrene, diphenyl, diphenylene oxide, quinoline and carbazole, and also phenylpyrazolones, which are capable of reacting as hydroxy compounds. The reaction is effected by bringing the hydroxy compound into aqueous or alcoholic alkaline solution, adding a hydrogenation catalyst, e.g. a nickel, nickel-chromium or nickel-cobalt catalyst, which may be distributed on a carrier, and treating with hydrogen under pressure, e.g. in a rotary or stirring autoclave. In examples, the following hydrogenations are carried out in the presence of a nickel-chromium catalyst prepared by drying an aqueous mixture of nickel carbonate and chromic acid and treating with nitrogen at 300 DEG C. and then with hydrogen at 350 DEG C.; (1) 2 : 3-hydroxynaphthoic acid to its 5 : 6 : 7 :-8-tetrahydro derivative; (2) 2 : 3-hydroxynaphthoic acid anilide to its 5 : 6 : 7 : 8-tetrahydro derivative; (3) 1-phenyl-3-methyl-5-pyrazolone to the corresponding 1-cyclohexyl compound. Reference is also made to the production of 2-hydroxy-5 : 6 : 7 : 8-tetrahydronaphthalene from b -naphthol. Azo dyes; azo dyes forming upon the material.--The alkaline solution of 5 : 6 : 7 : 8-tetrahydro-2 : 3-hydroxynaphthoic acid anilide yields a brown dyestuff by coupling in substance or on the fibre with diazo compounds, e.g. with diazotized p-nitraniline.ALSO:Aromatic or heterocyclic monohydroxy compounds containing at least two nuclei joined together directly, e.g. monohydroxy compounds of the naphthalene series such as a - and b -naphthol, hydroxynaphthoic acids and their amides, e.g. anilides, toluidides or xylidides, similar hydroxy compounds of anthracene, phenanthrene, diphenyl, diphenylene oxide, quinoline and carbazole, and also phenylpyrazolones, which are capable of reacting as hydroxy compounds, are partially hydrogenated, in the nucleus not containing the hydroxy group, and in some cases also partially in the nucleus containing the hydroxy group, by treating them in alkaline solution with hydrogen under increased pressure, e.g. above 25 atmospheres, preferably at 100--250 atmospheres, in the presence of hydrogenation catalysts, e.g. a nickel, nickel-chromium or nickel-cobalt catalyst, preferably at elevated temperatures, e.g. 70--150 DEG C. In examples, the following hydrogenations are effected in the presence of a nickel-chromium catalyst prepared by drying an aqueous mixture of nickel carbonate and chromic acid and treating with nitrogen at 300 DEG C. and then with hydrogen at 350 DEG C.: (1) 2 : 3-hydroxynaphthoic acid to its 5 : 6 : 7 : 8-tetrahydro derivative; (2) 2 : 3-hydroxynaphthoic acid anilide to its 5 : 6 : 7 : 8-tetrahydro derivative; (3) 1-phenyl-3-methyl-5-pyrazolone to the corresponding 1-cyclohexyl compound. Reference is also made to the production of 2-hydroxy-5 : 6 : 7 : 8-tetrahydronaphthalene from b -naphthol.