Combustion-derived CdO nanopowder as a heterogeneous basic catalyst for efficient synthesis of sulfonamides from aromatic amines using p-toluenesulfonyl chloride

A simple and rapid synthesis of CdO nanopowder via the solution combustion route employing l-(+)-tartaric acid as a fuel is reported for the first time. The catalyst was characterized by PXRD, SEM, TEM, BET surface area measurement, basic site measurement from back titration and FTIR. Combustion derived CdO nanopowder acts as a catalyst in the sulfonylation of amines with p-toluenesulfonyl chloride to obtain sulfonamides in excellent yield (85–95 %) and high purity under mild reaction conditions. CdO nanopowder has been found to be an efficient catalyst requiring a shorter reaction time (10–30 min) to obtain sulfonamide when compared with the commercial CdO powder requiring 2 h under similar conditions. The catalyst can be recovered and reused four times without any significant loss of catalytic activity. Potential role of CdO nanopowder in the synthesis of sulfonamides and its mechanism is proposed.