1-benzyl-1,4-dihydronicotinamide (BNAH). Two different mechanisms were found, i.e. one-step hydride transfer (polar pathway) and multi-step sequence initiated by single electron transfer (SET pathway). The effect of electron-withdrawing groups on the reactivity of the substrates were discussed in terms of Hammett substituent constants, 13C NMR chemical shift values and cyclic voltammetric redox potentials
一系列化合物中,ö -bromomethylbenzylidene甲基-丙二腈(1),二甲基Ô溴甲基benzylidenemalonate(2)和甲基α氰基Ö -bromomethylcinnamate(3)一种由NAD在黑暗中和在照射下被减少(P)H模型,1-苄基-1,4-二氢烟酰胺(BNAH)。发现了两种不同的机理,即一步法氢化物转移(极性途径)和由单电子转移引发的多步序列(SET途径)。根据哈米特取代基常数,13 C NMR化学位移值和循环伏安氧化还原电势及其相关性,讨论了吸电子基团对底物反应性的影响。
Process for preparation of pyridine derivatives of NK-1 receptor antagonist
申请人:Harrington J. Peter
公开号:US20060014959A1
公开(公告)日:2006-01-19
The present invention provides a process for preparing a pyridine compound of the formula:
wherein R
1
, R
2
, R
3
and a are those defined herein.
A novel bifunctional phosphine-catalyzed reaction was developed. Cross-RauhutâCurrier, Michael and aldol reactions were successfully combined into a domino process. This method offers a powerful approach to the construction of highly substituted cyclohexene skeletons.
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