MICROWAVE-INDUCED RAPID PREPARATION OF FLUORO-DERIVATIVES OF AMPHETAMINE, METHAMPHETAMINE, AND 3,4-METHYLENEDIOXYMETHAMPHETAMINE FOR GC-MS CONFIRMATION ASSAYS

We prepared trifluoroacetyl, pentafluoropropyl, and heptafluorobutyl d erivatives of amphetamine, methamphetamine, and 3,4-methylenedioxymeth amphetamine (MDMA) in 45 s, 1 min, and 6 min, respectively, by using m icrowave irradiation. Conventional techniques require heating the reac tion mixture for 15 min at 40 degrees C for trifluoroacetyl derivative s, 15 min at 75 degrees C for pentafluoropropyl derivatives, and 40 mi n at 60 degrees C for heptafluorobutyl derivatives. The mass-spectral fragmentation patterns and the gas-chromatographic retention times of the derivatives obtained by both microwave irradiation and conventiona l heating were similar. Perfluorooctanoyl derivatives of amphetamine c an be prepared quantitatively by either heating the reaction mixture f or 30 min at 60 degrees C or by 1 min of microwave irradiation. Conver sion of methamphetamine and MDMA to the corresponding perfluorooctanoy l derivatives was not quantitative by either technique, although the y ield of the derivative in the conventional technique was much higher.