Abstract 1,5‐Benzothiazepines and 1,5‐benzodiazepines have been synthesized in solvent‐free conditions from chalcones and o‐aminothiophenol or o‐phenylenediamine in the presence of inorganic support. Silica gel was found to be an effective support for the synthesis of 1,5‐benzothiazepines, whereas alumina was effective for the synthesis of 1,5‐benzodiazepines.