The new 4'- hydroxy and 3'- aldehyde phase- 1 metabolites of butobarbitone and
pentobarbitone are fully synthesized for the first time. These metabolites were used to
idenfity and quantify the natural metabolites in human urine after single and multiple
doses of these drugs. The synthesized metobolites have spectral characterizations (IR,
NMR, U.V. and mass spectroscopy) consisted with the assigned structures