40200-14-4Relevant academic research and scientific papers
Catalytic hydrogenation of 1,4-phenylenediamine to 1,4-cyclohexanediamine
Ma, Hongxian,Cai, Jianguo
, p. 397 - 403 (2014)
Catalytic hydrogenation of 1,4-phenylenediamine to 1,4-cyclohexanediamine using Ru/Al2O3 as a catalyst was carried out in water, and the results were compared with those in isopropanol and SC-CO2. 80% 1,4-phenylenediamine conversion with 87% selectivity to 1,4-cyclohexanediamine was achieved on 5% Ru/Al2O3 catalyst at 90°C and H2 pressure of 4 MPa. The hydrogenation of 1,4-phenylenediamine is influenced by the solvent. A systematic study of the hydrogenation of 1,4-phenylenediamine revealed that the reaction was consecutive. The longer the time, the lower was the CHDA selectivity. Also, the reaction temperature was an important parameter and played a vital role in preventing the formation of side products. Pleiades Publishing, Ltd., 2014.
Preparation of trans cyclohexane 1,4 diisocyanate
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, (2008/06/13)
A process is disclosed for selectively making trans-cyclohexane-1,4-diisocyanate, trans-cyclohexane-1,4-diamine, a trans-cyclohexane-1,4-diurethane, a trans-cyclohexane-1,4-diurea and trans-cyclohexane-1,4-disulphonyl urea by reacting ammonia with a mixture of cis and trans-cyclohexane-1,4-dicarboxylic acid, a lower alkyl ester, a glycol ester, an oligomeric ester or a polyester to make a solid trans-dicarboxylic acid diamide in a first step. The diamide is chlorinated to form cyclohexane-1,4-dicarboxylic acid-bis-N-chloramide. The latter compound is then converted into a (a) trans-cyclohexane-1,4-diamine with an alkali metal hydroxide or alkaline earth metal hydroxide; or into a (b) a trans-cyclohexane-1,4-diurethane by reaction with an alcohol or glycol in a reaction mixture containing an alkali metal hydroxide or alkaline earth metal hydroxide; or into (c) a trans-cyclohexane-1,4-diurea by reaction with a primary or secondary amine in a reaction mixture containing an alkali metal hydroxide or alkaline earth metal hydroxide; or into a (d) trans-cyclohexane-1,4-sulphonyl urea by reaction with a primary sulphonamide in a reaction mixture containing an alkali metal hydroxide and dimethyl formamide and water. The diurea prepared in (c) may be converted into trans-cyclohexane-1,4-diisocyanate with gaseous hydrogen chloride in an inert solvent. The diurethane prepared in (b) and the disulphonyl urea prepared in (d) may be thermally decomposed into trans-cyclohexane-1,4-diisocyanate.
