Carbromal
![Carbromal synthesis: DE 225710 (1910);[2][3] Patent literature:[4][5]](/uploads/202501/03/Carbromal_synthesis.svg1406.png)
Carbromal is a hypnotic/sedative originally synthesized in 1909 by Bayer.
Diethylmalonic acid is decarboxylated to 2-ethylvaleric acid then converted via a Hell-Volhard-Zelinsky reaction to α-bromo-α-ethylbutyryl bromide. Reaction with urea with affords carbromal (4).