| 摘要 |
<p>1,3-Diaryl triazenes, e.g., 1,3-diphenyltriazene, intermediates in the synthesis of aromatic diamines, e.g., p-phenylenediamine, are prepared by catalytically oxidizing ammonia, and subsequently the resulting nitric oxide, with a gas comprising diluted molecular oxygen, e.g., air, so as to produce a gas mixture containing dilute NOx, i.e., NO2 preferably admixed with NO, a being (1 + n), wherein n is the NO2 fraction of the NOx; and contacting the gas mixture, preferably at a temperature in the range of about from 25.degree. to 350.degree.C, with excess primary aromatic monoamine, e.g., aniline, so as to result in a monomamine temperature in the range of about from 25.degree. to 90.degree.C, preferably 40.degree. to 60.degree.C, during contact. Highest yields of triazene are obtained when the x in NOx is about from 1.3 to 1.7, and the amount of NOx gas mixture contacted with the monoamine and the time of contact are such that at least about 60% by weight of the monoamine remains unconsumed. A gas mixture temperature just prior to gas contact with the liquid monoamine in the range of about from 110.degree. to 275.degree.C is more preferred under certain circumstances.</p> |
