Microwave-induced Mannich reaction — Synthesis of some Mannich derivatives of p -aminophenol

Mono and bis substituted dialkylamino alkyl-p-aminophenol 3 are prepared by treating paracetamol 1 with formaldehyde and appropriate secondary amines followed by deacetylation using 6 M HCI in unmodified domestic microwave oven in unsealed borosil vessels. The compounds are obtained within a short duration of time (3 min). The rate of the reaction is found to be accelerated by about 60 fold when compared to conventional heating.