Synthesis of methaqualone and its diphasic titration in pure and tablet forms.

A one-step synthesis of methaqualone from N-acetylanthranilic acid and o-toluidine in the absence of a catalyst is described. A rapid diphasic titration procedure for its microestimation in pure and tablet forms, using dioctyl sodium sulfosuccinate and dimethyl yellow screened with oracet blue B, is proposed. The data were compared with those obtained from nonaqueous titration methods.