One-pot tandem synthesis of 2,3-unsubstituted indoles, an improved Leimgruber–Batchoindole synthesis

A concise, fast and efficient one-pot methodology has been developed for preparing 2,3-unsubstituted indoles from 2-nitrotoluenes and dimethylformamide dimethyl acetal. Compared with the classical Leimgruber–Batcho reaction, such a one-pot process simplified the operation procedures, generated less by-products and chemical residues, and resulted in higher overall yields in a shorter reaction time.