Research and Development of an Efficient Process for the Construction of the 2,4,5-Substituted Pyridines of NK-1 Receptor Antagonists
作者:Peter J. Harrington、Dave Johnston、Henk Moorlag、Jim-Wah Wong、L. Mark Hodges、Les Harris、Gerald K. McEwen、Blair Smallwood
DOI:10.1021/op060128m
日期:2006.11.1
oxo-1,3‘-bipyridinium inner salts from 1-(2-amino-2-oxoethyl)pyridinium chloride, aromatic aldehydes, and ethyl cyanoacetate in the presence of a base. Reaction of these salts with phosphorus oxychloride affords 4-aryl-3-cyano-2,6-dichloropyridines. These are efficiently converted to nicotinamide precursors of the Roche NK-1 receptor antagonists by regioselective displacement of one chlorine by an
罗氏(Roche)已为新型强效NK 1受体拮抗剂确定了2,4,5-三取代的吡啶模板。构建这些NK-1受体拮抗剂的吡啶核心的先前策略涉及2,5-二取代吡啶的功能化。现在我们报告从商品成分构建吡啶核的情况。Shestopalov报告了反式的合成1-(2-氨基)的-4'-芳基-5'-氰基-1',2',3',4'-四氢-6'-羟基-2'-氧代-1,3'-联吡啶鎓内盐在碱的存在下,氯化-2-氧代乙基)吡啶鎓,芳族醛和氰基乙酸乙酯。这些盐与三氯氧化磷反应,得到4-芳基-3-氰基-2,6-二氯吡啶。通过胺对一个氯的区域选择性置换,剩余氯的氢解和腈水解,这些化合物可有效地转化为罗氏NK-1受体拮抗剂的烟酰胺前体。