What is "apronal"

Apronal (brand name Sedormid), or apronalide, also known as allylisopropylacetylurea or allylisopropylacetylcarbamide, is a hypnotic/ sedative drug of the ureide (acylurea) group synthesized in 1926 by Hoffmann-La Roche that is no longer used. Though it is not a barbiturate, apronalide is similar in structure to the barbiturates (being an open-chain carbamide instead of having a heterocyclic ring). In accordance, it is similar in action to the barbiturates, although considerably milder in comparison (formerly used as a daytime sedative at doses of 1 to 2 grams every 3 to 4 hours). Upon the finding that it caused patients to develop thrombocytopenic purpura, apronalide was withdrawn from clinical use.