Tandem oxidation processes for the regioselective preparation of 5-substituted and 6-substituted 1,2,4-triazines
作者:Surat Laphookhieo、Stuart Jones、Steven A. Raw、Yolanda Fernández Sainz、Richard J.K. Taylor
DOI:10.1016/j.tetlet.2006.03.178
日期:2006.6
undergo MnO2-mediated oxidation, followed by in situ trapping with 2-pyridylamidrazone, to give 3-pyridyl-5-substituted 1,2,4-triazines in a one-pot procedure, which avoids the need to isolate the reactive α-ketoaldehyde intermediates. By modifying this procedure to allow condensation prior to oxidation, the corresponding 6-substituted 1,2,4-triazines were obtained. The preparation of a novel unsymmetrical
α-羟基酮经历MnO 2介导的氧化,然后用2-吡啶基dra唑酮原位捕集,通过一锅法制得3-吡啶基-5-取代的1,2,4-三嗪,无需分离反应性α-酮醛中间体。通过修改该程序以允许在氧化之前缩合,获得了相应的6-取代的1,2,4-三嗪。还描述了使用本文制备的吡啶基1,2,4-三嗪之一制备新颖的不对称2,2'-联吡啶。