Synthesis and Electrochemical Behaviour of 2-N-Substituted Indazoles.
作者:B. A. Frontana-Uribe、C. Moinet、Yves Dory、Jean Marc Chapuzet、Jean Lessard、André Tallec、Tatsuya Shono、H. Toftlund
DOI:10.3891/acta.chem.scand.53-0814
日期:——
A new 2-N-aryl-3-methoxycarbonylindazole synthesis from the 6 F mol(-1) reduction of appropriately substituted aryl-nitrones has been developed. The indazoles bearing an electron withdrawing group in the 2-position are electroreducible compounds at high negative potentials producing selectively the corresponding 2-N-substituted indazolines in aqueous alcoholic medium. The nitrile and ester groups are not reduced under the reaction conditions. Three new 2-N-aryl-indazolines were synthesized and characterized. A second electron withdrawing group attached at the 3-position leads to a less cathodic reduction of the 2-N-aryl-3-methoxycarbonylindazole. An appropriately substituted indazoline was used to generate ill situ a new tetracyclic heterocycle.