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m-Aminophenol
Published in John R. Kosak, Thomas A. Johnson, Catalysis of Organic Reactions, 2020
The highest 3-ACI salt selectivities were obtained in the narrow temperature range of 50–70°C. Higher temperatures gave increasing amounts of cyclohexylamine, cyclohexanol, cyclohexanone, and dicyclohexylamine by-products (Table 2). Temperatures of 120–150°C give no 3-ACI but only the above by-products. These by-products have been previously found in the hydrogenation of aniline in the presence of acetic acid and a catalytic quantity of a group VIII metal [6], and in the rhodium- and rutheniumcatalyzed hydrogenation of MPD and PPD in acetic acid [5]. No hydro-genolysis of 1,3-diaminocyclohexane was observed in a separate experiment under these conditions [5]. Thus, all of these products are apparently formed via the transition-metal-catalyzed hydrogenolysis of a C—N bond of the MPD to give aniline followed by reduction and hydrolysis of the intermediate imine to cyclohexanone or cyclohexanol. The ketone or imine can then condense with the cyclohexylamine and on subsequent hydrogenation give dicyclohexylamine.
Recognition of the prioritized types and individual of pharmaceuticals and personal care products (PPCPs) in the drinking water of Shanghai and a health risk assessment
Published in Human and Ecological Risk Assessment: An International Journal, 2019
Guoqiang Gu, Haowen Yin, Qing Zhu, Lu Shen, Kun Zhang, Min Liu, Qiang Wu
Dicyclohexylamine inhibits spermidine synthase (Pegg and Mccann 1982) and is used in animal and bacterial systems (Hibasami et al. 1980). Dicyclohexylamine was detected in all samples at concentrations ranging from 0.11 ng/L to 11.8 ng/L, with an average concentration of 4.7 ng/L. This value was the highest detected concentration of all the PPCPs examined, as shown in Table 1. Although the enzyme inhibitor only contains one analyte, it had the highest concentration and detection frequency (Figure 3). It was also determined that dicyclohexylamine was the main component in all samples, as shown in Figure 4. The proportion of dicyclohexylamine was higher than 50% in 16 of 35 samples, and it had a maximum value of 86.3%. As a result, the compound accounted for nearly 50% of all detected PPCPs, as shown in Figure 5. Dicyclohexylamine is used as both an enzyme inhibitor and an important initiator in chemical synthesis (Han et al. 2013). Additionally, one of the most important uses of dicyclohexylamine is as a vapor-phase corrosion inhibitor (Fazullin et al. 2017). The prominence of dicyclohexylamine in pollution may result from these extensive and varied methods of industrial emission.