4-Aminopyridines undergo surprisingly rapid and highly selective H/D exchange at C-2 and C-6 in neutral D2O upon microwave irradiation at only 190 °C for two hours in a sealed vessel. This method contrasts and complements acid-mediated H/D exchange, requires no catalyst, and is appropriate for the synthesis of deuterium isotopologues of N- and C-substituted 4-aminopyridines and a benzofused (quinoline) analogue.
Key words
deuteration - heterocycles - microwave synthesis