Chlorotrimethylsilane (TMSCI) is effective as a catalyst for the preparation of 1,2-dihydro-1-arylnaphtho[1,2-e] [1,3]oxazine-3- ones using a one-pot condensation of 2-naphthol, aromatic aldehydes and urea in DMF as solvent. The reaction times, temperature, and catalyst amounts were varied.