M. Pallavicini et al., Synthesis, free solution capillary electrophoresis separation and toxicityof seven potential impurities of dobutamine, ARZNEI-FOR, 51(1), 2001, pp. 18-23
The seven O-methylated analogs of dobutamine ((+/-)-4-[2-[[3-(p-hydroxyphen
yl)-1-methylpropyl] amino]ethyl]pyrocatechol, CAS 34368-04-2), a trihydroxy
secondary amine, can be considered potential impurities of the latter, the
ultimate step of the synthesis of dobutamine being the deprotection of the
three phenolic groups. In order to enable the detection and the identifica
tion of such a contamination, the di- and the monomethylated derivatives of
dobutamine were prepared and their mixture with dobutamine and its trimeth
oxy precursor completely resolved by Free Solution Capillary Electrophoresi
s (FSCE). Indeed, the above impurities proved to occur in dobutamine in con
sequence of improper demethylation conditions and to be significantly more
toxic than the latter.