Abuse of the hypnotic quinazolinone is well recognized and increasing. Clandestine laboratories producing methaqualone (2-methyl-3-ortho-tolyl-4(3H) quinazolinone) and mecloqualone (2-methyl-3-ortho-chlorophenyl-4(3H) quinazolinone) have been discovered throughout the United States. These laboratories utilize one of many synthesis routes to produce the illicit quinazolinone. Frequently, the clandestine chemist has little, if any, formal education in chemistry; does not keep notes; and does not label flasks and beakers containing solutions. The forensic chemist may be asked to analyze unmarked reaction mixtures that were seized in a clandestine laboratory raid. As a result, a rapid method of isolation and identification of the precursors and products of such a mixture is presented.