Base-free amination of BH acetates of 2-chloroquinolinyl-3-carboxaldehydes: a facile route to the synthesis of N-substituted-1,2-dihydrobenzo[b][1,8]naphthyridines

An efficient base-free one-pot synthesis of 1,2-dihydrobenzo[b][1,8]naphthyridines from BH acetates of 2-chloro-3-formylquinolines and activated alkenes followed by their acetylation, with different amines have been reported. These reactions are completed in very short time and provided the products in good to excellent yields. We further explored the scope of BH acetate with carbon nucleophile providing a new route to the synthesis of acridine derivative in excellent yield under mild condition.