In(OTf)3-mediated synthesis of substituted pyridazines
作者:Meng-Yang Chang、Yi-Ju Lu、Yu-Chieh Cheng
DOI:10.1016/j.tet.2015.07.025
日期:2015.9
In(OTf)(3) (4c)-mediated one-pot (4+2) cyclocondensation of gamma-alkynones 3 with N2H4(aq) in dioxane affords substituted pyridazines 5 in good yields via a sequential desulfonative or dehydrogenative aromatization. The facile transformation proceeds by a facile synthetic sequence starting with an alpha-propargylation of beta-ketosulfones 1 and a cyclocondensation of gamma-alkynones 3 with N2H4(aq). The method provides a mild and efficient condition. Moreover, this route can be enlarged to multigram scale. (C) 2015 Elsevier Ltd. All rights reserved.