Literature examples illustrating the use of oxalyl chloride to prepare dicarboxylicacid anhydrides are surprisingly limited. At the same time, we have discovered a method involving the use of this readily available reagent which allowed the preparation of novel cyclic anhydrides where other, more conventional, methods had failed. Herein, we demonstrate that the method is applicable to a wide diversity
Complications in the Castagnoli-Cushman reaction: An unusual course of reaction between cyclic anhydrides and sterically hindered indolenines
作者:Maria Chizhova、Dmitry Dar'in、Mikhail Krasavin
DOI:10.1016/j.tetlet.2017.07.077
日期:2017.8
Attempted reaction of indolenines (which represent rather sterically hindered cyclic imines) with a series of dicarboxylic acidanhydrides yielded no expected product, the Castagnoli-Cushman lactam. Instead, products presumably formed via N-acyliminium species trapping by a carboxylate anion. Among them, hydrolytically labile 2:2 adducts of an indolenine and a cyclicanhydride, containing a 16-membered
The discovery of a sulphonamide by-product with VLA-4 antagonistic activity led to a series of potent, small molecule VLA-4 antagonists. Synthesis, SAR and in vivo evaluation of the selected compound will be presented. (C) 2003 Elsevier Ltd. All rights reserved.