Study on selectivity in the reaction of 2-substituted pyridinium- N -imines with dimethyl acetylenedicarboxylate
作者:Vyacheslav I. Supranovich、Aleksey Yu. Vorob’ev、Gennady I. Borodkin、Yury V. Gatilov、Vyacheslav G. Shubin
DOI:10.1016/j.tetlet.2016.01.092
日期:2016.3
Reactions of 2-X-pyridinium-N-imines (X = F, Cl, Br, CN, OPh, NH2, N-morpholine) with dimethyl acetylenedicarboxylate (DMAD) have been studied. In the case of X = Cl, Br, CN, OPh both 7-substituted- and 7-H-pyrazolo[1,5-a]pyridines are formed. The 7-H/7-X ratio usually increases with the growing solvent polarity. The reaction of N-amino-2-iminopyridine with DMAD gives substituted pyrido[1,2-b][1,2
研究了2-X-吡啶鎓-N-亚胺(X = F,Cl,Br,CN,OPh,NH 2和N-吗啉)与乙炔二羧酸二甲酯(DMAD)的反应。在X = Cl,Br,CN,OPh的情况下,同时形成7-取代的和7- H-吡唑并[1,5- a ]吡啶。7-H / 7-X比率通常随着溶剂极性的增加而增加。N-氨基-2-亚氨基吡啶与DMAD的反应得到取代的吡啶并[1,2- b ] [1,2,4]三嗪。