## 2 Materials and Methods  
### Synthesis of the Target Compound  
All solvents and reagents were purchased from Merck and Sigma-Aldrich. Melting points were determined on a Boetius hot stage apparatus and are uncorrected. All the compounds were characterized by \({}^{1}\)H NMR, \({}^{13}\)CNMR, IR, and microanalysis. The purity of these compounds was determined by TLC using several solvent systems of different polarity. TLC was carried out on precoated 0.2 mm Fluka silica gel 60 plates (Merck KGaA, Darmstadt, Germany) using chloroform: diethyl ether: n-hexane = 6:3:1 as a chromatographic system. Elemental analyses were performed with a TruspecMicro (LECO, Monchengladbach, Germany). Neutral Al\({}_{2}\)O\({}_{3}\) was used for column chromatographic separation. The products, after evaporation of the solvent, were purified by recrystallization from diethyl ether. IR spectra were determined on a VERTEX 70 FT-IR spectrometer (Bruker Optics, Germany). \({}^{1}\)H NMR and \({}^{13}\)C NMR spectra were recorded on a Bruker Avance III HD 500 spectrometer (Bruker, Billerica, MA, USA) at 500 MHz (\({}^{1}\)H NMR) and 125 MHz (\({}^{13}\)C NMR), respectively. Chemical shifts are provided in relative ppm and were referenced against tetramethylsilane (TMS) (\(\delta\) = 0.00 ppm) as an internal standard; the coupling constants are indicated in Hz. The NMR spectra were recorded at room temperature (ac. 295 K). Mass analyses were carried out on a Q Exactive Plus mass spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). Liquid chromatography with mass detection (LC-MS/MS) of analytes was performed using the chromatographic system Thermo Dionex Ultimate 3000 LC and triple quadrupole mass spectrometer Thermo TSQ Quantum Access MAX (Thermo Fisher Scientific, MA, USA), with HESI (Heated Electrospray Ionization). The chromatographic system includes a quaternary two-piston pump, autosampler, and column thermostat. Chromatographic separation was performed under isocratic conditions on a coreshell AccucoreTM RP-MS 100 \(\times\) 2.1 mm, 2.6 \(\upmu\)m particles analytical column (Thermo Fisher Scientific, MA, USA). Chromotographic Condition and MS Parameter Optimization: To avoid residual signals and inaccuracies, the chromatographic conditions were established in an isocratic mode for sample analysis. The peak shapes and MS signals of the analytes were improved using mobile phases A: 0.1% formic acid in acetonitrile-water (90:10, \(v/v\)) and B: 0.1% formic acid in acetonitrile-water (10:90, \(v/v\)) in 40:60 (A:B) ratio at flow rate 0.150 mL min\({}^{-1}\). HESI was used for analyte detection in positive ionization mode with spray voltage \(-\)4000 V; source temperature 400 \({}^{\circ}\)C; sheath gas pressure 30; vaporizer temperature 350 \({}^{\circ}\)C; capillary temperature 270 \({}^{\circ}\)C. Protonated molecules of analyte and IS were used as precursor ions for selected reaction monitoring (SRM). IQP (**6**) was synthesized from starting (2S)-methyl-N-toyslaziridine **1**, a known compound prepared according to a standard procedure from commercially available (S)-alanine [19]. A nucleophilic ring opening with 4-bromoanisole **2** in THF and dry CuI was obtained. The desulfonylation was carried out with magnesium in methanol under ultrasonic conditions [19], and we did not find any racemization of the stereogenic center. That allows us to obtain (S)-1-(3,4-dimethoxyyphenyl)propan-2-amine **4**. (S)-1-(3,4-dimethoxyyphenyl)propan-2-amine (4): yellow liquid, \({}^{1}\)H-NMR: 1.17 (d, J = 6.1, 3H, CH-CH\({}_{3}\)), 2.03 (broad s, 2H, NH\({}_{2}\)), 2.48-2.56 (m, 1H, CH\({}_{2}\)), 2.67-2.74 (m, 1H, CH\({}_{2}\)), 3.16-3.21 (m,1H, CH-CH\({}_{3}\)), 3.88 (s, 3H, OCH\({}_{3}\)), 3.90 (s, 3H, OCH\({}_{3}\)), 6.74-6.77 (m, 2H, Ar), 6.82-6.85 (m, 1H, Ar), 13C-NMR: 148.9, 147.6, 121.2, 112.5, 111.4, 55.95, 55.9, 48.6, 45.8, 23.2. Anl. calcd. for C\({}_{11}\)H\({}_{17}\)NO\({}_{2}\): C, 67.66; H, 8.78; N, 7.17; Found: C, 67.67; H, 8.75; N, 7.18. HRMS Electrospray ionization (ESI) m/z 197.8069.