Synthesis, structural characterization, analytical profiling, and application to authentic samples of synthesized Phase I metabolites of the synthetic cannabinoid 5F-MDMB-PICA

5F-MDMB-PICA, an indole-type synthetic cannabinoid (SC), was classified illicit globally in 2020. Although the extensive metabolism of 5F-MDMB-PICA in the human body warrants the development of robust analytical methods for metabolite detection and quantification, a current lack of reference standards for characteristic metabolites hinders such method creation. This work described the synthesis of 18 reference standards for 5F-MDMB-PICA and its possible Phase I metabolites, including three hydroxylated positional isomers R14 to R16 . All the compounds were systematic characterized via nuclear magnetic resonance, Fourier transform infrared spectroscopy, and high-resolution mass spectrometry. Furthermore, two methods were developed for the simultaneous detection of all standards using liquid chromatography–tandem mass spectrometry and ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry. By comparison with authentic samples, R17 was identified as a suitable urine biomarker for 5F-MDMB-PICA uptake.