A practical synthesis of LFA-1 inhibitors utilizing CuCl-promoted intramolecular cyclization of thiohydantoins
作者:Xiao-jun Wang、Li Zhang、Yibo Xu、Dhileepkumar Krishnamurthy、Richard Varsolona、Laurence Nummy、Sherry Shen、Rogelio P. Frutos、Denis Byrne、J.C. Chung、Vittorio Farina、Chris H. Senanayake
DOI:10.1016/j.tetlet.2004.11.065
日期:2005.1
An efficient and chromatography-free approach for synthesis of a new class of LFA- I inhibitor was developed. A copper(I) chloride-promoted intramolecular cyclization of thiohydantoins 7a-b serves as a key step to highly functionalized bicyclic guanidines 5a-b, that were subsequently converted to H-imidazol[l,2-a]imidazol-2-one LFA-1 inhibitors. This process has been successfully implemented in the pilot plant to produce multikilogram quantities of LFA-1 inhibitors such as la-b. (C) 2004 Elsevier Ltd. All ri.-hts reserved