2615-25-0Relevant articles and documents
The Rhodium Catalysed Direct Conversion of Phenols to Primary Cyclohexylamines
Tomkins, Patrick,Valgaeren, Carlot,Adriaensen, Koen,Cuypers, Thomas,Vos, Dirk E. De
, p. 3689 - 3693 (2018/07/31)
Cyclohexylamines are important intermediates in chemical industry, which are currently produced from petrochemical sources. Phenols, however, are an attractive sustainable feedstock. We here demonstrate the transformation of phenols with ammonia to primary cyclohexylamines. In contrast to previously reported chemistry which used palladium catalysts, we here show that rhodium is an excellent catalyst for the formation of primary cyclohexylamines. Different parameters were studied and it was shown that the reaction is applicable to a scope of phenolic compounds providing high selectivity.
Catalytic hydrogenation of 1,4-phenylenediamine to 1,4-cyclohexanediamine
Ma, Hongxian,Cai, Jianguo
, p. 397 - 403 (2014/08/18)
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.