Synthesis and Aqueous Chemistry of α-Acetoxy-<i>N</i>-nitrosomorpholine: Reactive Intermediates and Products
作者:Charles N. Zink、Hyun-Joong Kim、James C. Fishbein
DOI:10.1021/jo051936z
日期:2006.1.1
reactivity of 7 at neutral pH compared with its carbon analogue, α-acetoxy-N-nitrosopiperidine, is also consistent with the electronic effects expected for such a reaction. The dinitrophenylhydrazones derived from pH-independent and acid-catalyzed reactions are identical in kind and quantity, within experimental error, to those observed in the decay of α-hydroxy-N-nitrosomorpholine. Decay of 7 in the presence
α-乙酰氧基-N-亚硝基吗啉(7)是通过N-乙酰基吗啉在甲醇中的阳极氧化反应开始合成的。经过氰化物为甲氧基的交换和水解后,N-亚硝基吗啉酸的55%收率比我们最初的10步法提高了约10倍,并且很容易转化为7。在1至12的pH范围内,在25°C和1 M离子强度下在水性介质中7的分解动力学进行了研究。在所有pH值下反应均表现出良好的一级动力学。k 0的对数,针对pH的与缓冲液无关的分解速率常数表明,pH无关的反应在中性pH区域占主导,而酸催化和碱催化的反应分别在低pH和高pH区域占主导。在醋酸盐离子浓度增加的情况下,在中性pH下反应会导致k obsd值降低至一个明显的极限值,该值与通过捕获N和竞争性碱催化水合N引起的普通离子抑制相一致。-亚硝基亚胺离子中间体。7在中性pH下的反应活性比其碳类似物α-乙酰氧基N小100倍-亚硝基哌啶也与这种反应预期的电子效应相一致。在实验误差范围内,与pH无关和酸