General. All chemicals were of reagent grade, purchased from commercial sources (e.g., Sigma-Aldrich, abcr, Enamine and BLDpharm) and used without further purification unless otherwise specified. Test compound 6 was obtained from TCI, test compound 7 was acquired from Sigma Aldrich, test compound 9 was obtained from Prestwick Chemical Libraries, and test compounds 10 and 52-54 were acquired from Enamine Ltd. All reactions were conducted in oven-dried glassware under Ar atmosphere and in absolute solvents. Other solvents, especially for work-up procedures, were of reagent grade or purified by distillation (isohexane, EtOAc, EtOH). Reactions were monitored by thin layer chromatography (TLC) on TLC Silica gel 60 F254 aluminum sheets by Merck and visualized under ultraviolet light (254 nm) or by in-process LC/MS. Purification by column chromatography (CC) was either performed using silica gel (40-60 μm) or performed on a puriFlash® XS520Plus system (Advion Inc., Ithaca, NY, USA) using high performance spherical silica columns (SIHP, 50 μm) by Interchim. Reverse phase CC was performed on a puriFlash® 5.250 system (Advion) using C18HP columns (SIHP, 15 μm) by Interchim and a gradient of 0.1% formic acid in H2O to 100% acetonitrile (HPLC gradient grade). Or semi-preparative purification was performed on a LCMS 2020 (Shimadzu, Duisburg, Germany) using a Luna 10μ C18(2) (250 × 21.20 nm)-column from Phenomenex LTD Deutschland (Aschaffenburg, Germany). As eluent mixtures of acetonitrile/0.1% aqueous formic acid were used, with a flow rate of 21 mL/min at r.t.. The following methods were used: linear gradient from 50 to 90% ACN over 10 min, 90% ACN for 5 min, linear gradient from 90 to 50% ACN over 1 min, 50% for 2 min (method A); 5% ACN over 2 min, linear gradient from 5% to 90% ACN over 12 min, 90% ACN for 6 min, linear gradient from 90% to 5% ACN over 1 min, 50% for 4 min (method B). NMR spectra were recorded on Bruker AV 300, Bruker AV 400, Bruker AV 500, Bruker Avance III HD 400, or Bruker Avance III HD 500 spectrometers (Bruker Corporation, Billerica, MA, USA). Deuterated solvents DMSO-d6, CDCl3, Acetone-d6, and MeOD-d4 used for NMR spectroscopy were purchased and used without further drying. Chemical shifts (δ) are reported in ppm relative to TMS as reference or residual solvent signal protons. Approximate coupling constants (J) are shown in Hertz (Hz). Mass spectra were obtained on a VG Platform II (Thermo Fischer Scientific, Inc., Waltham, MA, USA) using electrospray ionization (ESI) or on an Advion expression™ CMS (Advion) using atmospheric pressure chemical ionization (APCI) or on a LCMS 2020 (Shimadzu) equipped with an ESI-TOF. High resolution mass spectra were recorded on a MALDI LTQ ORBITRAP XL instrument or on a LTQ FT instrument for electrospray ionization (ESI) (Thermo Fisher Scientific) or on a Finnigan MAT 95 spectrometer (Thermo Fisher Scientific) using electron impact ionization (EI) at a source temperature of 250 °C and an electron energy of 70 eV with a method dependent range from 40 to 1040 u. Compound purity was analyzed either by HPLC-UV, HPLC-MS or qHNMR quantification. For HPLC-UV, purity was analyzed either on a Waters 600 Controller HPLC using a Waters 2487 Dual Absorbance Detector and Waters 717 plus Autosampler or on a Hitachi Chromaster with a 5160 pump system, using a DAD 5430 and 5260 Autosampler both equipped with a MultoHigh100 RP18-5 μ 250x4 mm column (CS-Chromatographie Service GmbH, Langerwehe, Germany) using a gradient (H2O+0.1% formic acid/MeOH 80:20 isocratic for 5 min to MeOH after additional 45 min and MeOH for additional 10 min) at a flow rate of 1 mL/min and UV-detection at 254 nm and 280 nm (method C) or using a gradient (H2O+0.1% formic acid/MeOH 60:40 isocratic for 5 min to MeOH after additional 25 min and MeOH for additional 10 min) at a flow rate of 1 mL/min and UV-detection at 245 nm and 280 nm (method D). Or, HPLC-UV purity was analyzed on a LCMS 2020 (Shimadzu) using a Luna 10u C18(2) (250 × 4.6 nm)-column from (Phenomenex LTD Deutschland). The system is equipped with a SPD 20A UV/VIS detector (λ = 240/280 nm) and an ESI-TOF (measuring in the positive-and/or negative-ion mode). As eluent mixtures of acetonitrile/0.1% aqueous formic acid were used, with a flow rate of 0.1 mL/min at r.t.. The following method was used: linear gradient from 50 to 90% ACN over 10 min, 90% ACN for 5 min, linear gradient from 90 to 50% ACN over 1 min, 50% for 2 min (method A). Purity of the compounds was determined by integrating the peaks of the UV-chromatogram. Quantitative 1 H NMR (qHNMR) were acquired according to a method described by Pauli et al. with internal calibration. The qHNMR measurements were carried out under conditions allowing complete relaxation to assure the exact determination of peak area ratios. All final compounds for biological evaluation had a purity of >95% according to qHNMR or to HPLC-MS or to HPLC-UV analysis at wavelengths 254 and 280 nm. Synthesis and analytical characterization of 11, 24, 28, 33-35, 42-50, 55-60, and their precursors are described in the Supporting Information.