Mecloqualone is a quinazoline-class GABAergic and an analog of methaqualone. It acts as an agonist of the beta subtype of GABAa receptor and induces sedative, hypnotic and anxiolytic effects. Mecloqualone was marketed (mostly in france) under the names Nubrene and Casfen for the treatment of insomnia. Mecloqualone is no longer prescribed because of concerns about its potential for abuse and overdose. In the United States, it is registered as a Schedule-I non-narcotic controlled substance.

Mecloqualone:
https://drugs.ncats.io/drug/09XU4VDV7E

First made in 1960. Mecloqualone is faster-acting but shorter-lasting than methaqualone and so was used only as a sleeping pill, in contrast to methaqualone, which was used as a general purpose anxiolytic as well. Mecloqualone was never as widely used as methaqualone.