Synthesis and characterization of novel azo-morphine derivatives for possible use in abused drugs analysis.

A new simple and fast spectroscopic method was presented as a new marker for heroin use. Novel azo-morphine derivatives with spectroscopic absorption peaks ranging from 330-470 nm, were synthesized by the coupling of morphine (M) and 6-acetyl morphine (6-AM) with freshly prepared diazonium salt of aniline hydrochloride at 0 degrees C. However, no reaction was observed with codeine under the same reaction conditions. Separation of azo dyes was performed by TLC using tetrahydrofuran and dichloromethane in the ratio 1:1. The chemical structure of the products was established by their microanalysis, NMR, IR, UV-vis, and mass spectroscopies. Electronic absorption and excitation spectra of the dyes were measured in solvents of different polarities. The dyes exhibited positive solvatochromism, i.e., a bathochromic band shift as the solvent polarity is increased. Also, the fluorescence quantum yield was sensitive to the polarity and the pH of the medium. The UV-vis spectroscopy of spiked compounds in human urine samples was also reported. The drugs (M, 6-AM and mixture of both) were coupled with freshly prepared diazonium salt even at very low concentration of the drugs 10(-9)M.