The Synthesis and analysis of methaqualone and some positional structural isomers thereof

Abstract

An extensive review of the reported synthesis of methaqualone (2-methyl-3-ο-tolyl-4(3H)-quinazolinone) and some positional and structural isomers of methaqualone is given. A detailed summary of the synthetic routes reviewed is given as an appendix. Methaqualone, four previously reported, and seven until hereto unreported isomers of methaqualone were prepared using a modified, known synthetic route for quinazolinones. The modified route allowed for the rapid laboratory scale preparation of the desired quinazolinones in high yields. Melting points are given. The prepared compounds were characterized using various organic analytical techniques. NMR and IR was found to be the most specific single techniques for the effectively and unequivocally differentiation between the studied compounds. The most convenient, and equally specific, differentiation was achieved using coupled gas-liquid chromatography. The thin-layer chromatography and liquid chromatography systems evaluated proved of no value in differentiating the thirteen isomers.