An efficient aerobic oxidative aromatization of Hantzsch 1,4-dihydropyridines and 1,3,5-trisubstituted pyrazolines
文摘
4-Substituted Hantzsch 1,4-dihydropyridines and 1,3,5-trisubstituted pyrazolines were oxidized to the corresponding pyridines and pyrazoles, respectively, in high yields by molecular oxygen in the presence of catalytic amount of N-hydroxyphthalimide (NHPI) and Co(OAc)2 in acetonitrile at room temperature.