Reduction of nitro- and nitroso-compounds by tervalent phosphorus reagents. Part VII. A new synthesis of phenothiazines involving a new molecular rearrangement
作者:J. I. G. Cadogan、S. Kulik、C. Thomson、M. J. Todd
DOI:10.1039/j39700002437
日期:——
Reductive cyclisation of aryl 2-nitroaryl sulphides by triethyl phosphite provides a new synthesis of phenothiazines (yields ca. 50–85%) which is superior to that involving the thermal decomposition of aryl 2-azidoaryl sulphides (yields ca. 30%). Both reactions proceed via a novel molecular rearrangement whereby, for example, 4-chlorophenyl 2-nitrophenyl sulphide gives 3-chlorophenothiazine, whereas 4
亚磷酸三乙酯对芳基2-硝基芳基硫醚的还原环化提供了吩噻嗪的新合成方法(产率约50-85%),优于涉及芳基2-叠氮基芳基硫醚热分解的产率(约30%)。两个反应均通过新颖的分子重排进行,例如,4-氯苯基2-硝基苯基硫化物产生3-氯吩噻嗪,而4-氯-2-硝基苯基苯基硫化物产生2-氯吩噻嗪。[4- 2 H]苯基2-硝基苯基硫化物类似地得到[3- 2 H]吩噻嗪,如通过比较其阳离子自由基的esr光谱与计算机模拟的[2- 2 H]-和[3]比较- 2H]-吩噻嗪。还报道了吩噻嗪通过磷酸三乙酯的便利的N-乙基化。