| 摘要 |
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, x 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 DEG to 350 DEG C., with excess primary aromatic monoamine, e.g., aniline, so as to result in a monoamine temperature in the range of about from 25 DEG to 90 DEG C., preferably 40 DEG to 60 DEG 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 DEG to 275 DEG C. is more preferred under certain circumstances. |
