The photoinduced and thermal denitrogenation of crystalline triazolines with bulky substituents leads to the quantitative formation of aziridines in clean solid-to-solid reactions despite very large structural changes in the transition from reactant to product. Analysis of the reaction progress by powder X-ray diffraction, solid-state (13)C CPMAS NMR, solid-state FTIR spectroscopy, and thermal analysis has revealed that solid-to-solid reactions proceed either through metastable phases susceptible to amorphization or by mechanisms that involve a reconstructive phase transition that culminates in the formation of the stable phase of the product. While the key for a solid-to-solid transformation is that the reaction occurs below the eutectic temperature of the reactant and product two-component system, experimental evidence suggests that those reactions will undergo a reconstructive phase transition when they take place above the glass transition temperature.

We performed an extensive analysis about the reaction conditions of the 1,4-Michael addition of amino acids to 1,4-naphthoquinone and substitution to 2,3-dichloronaphthoquinone, and a complete evaluation of stoichiometry, use of different bases, and the pH influence was performed. We were able to show that microwave-assisted synthesis is the best method for the synthesis of naphthoquinone–amino acid and chloride–naphthoquinone–amino acid derivatives with 79–91% and 78–91% yields, respectively. The cyclic voltammetry profiles showed that both series of naphthoquinone–amino acid derivatives mainly display one quasi-reversible redox reaction process. Interestingly, it was shown that naphthoquinone derivatives possess a selective antitumorigenic activity against cervix cancer cell lines and chloride–naphthoquinone–amino acid derivatives against breast cancer cell lines. Furthermore, the newly synthetized compounds with asparagine–naphthoquinones (3e and 4e) inhibited ~85% of SiHa cell proliferation. These results show promising compounds for specific cervical and breast cancer treatment.

The solid-state photodenitrogenation of crystalline triazolines proceeds with high efficiency to form the corresponding aziridines in high chemical yields upon selection of the proper irradiation wavelength. It was shown that the solid-to-solid reactions occur by formation of the product in metastable crystalline phases.

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Background: Fluoroquinolones are widely prescribed synthetic antimicrobial agents. Quinolones act by converting their targets, gyrase and topoisomerase IV, into toxic enzymes that fragment the bacterial chromosome; the irreversible DNA damage eventually causes the killing of bacteria. Thorough knowledge of the structure-activity relationship of quinolones is essential for the development of new drugs with improved activity against resistant strains. Methods: The compounds were screened for their antibacterial activity against 4 representing strains using the Kirby-Bauer disk diffusion method. Minimal inhibitory concentration (MIC) was determined by measuring the diameter of the inhibition zone using concentrations between 250 and 0.004 μg/mL. Results: MIC of derivatives 2, 3, and 4 showed potent antimicrobial activity against gram-positive and gram-negative bacteria. The effective concentrations were 0.860 μg/mL or lower. MIC for compounds 5-11 were between 120 and 515 μg/mL against Escherichia coli and Staphylococcus aureus, and substituted hydrazinoquinolones 7-10 showed poor antibacterial activity against gram-positive and gram-negative bacteria compared with other quinolones. Conclusion: Compounds obtained by modifications on C-7 of norfloxacin with the acetylated piperazinyl, halogen atoms, and substituted hydrazinyl showed good in vitro activity - some even better than the original compound.

TABLE OF CONTENTS General Information S1General procedure for compounds 16a-l (GP1) S2Synthesis and NMR spectra of the products 16a-l S2-S19General procedure for compounds 17a-m (GP2) S20Synthesis and NMR spectra of the products 17a-m S20-S39 General informationReagents and solvents were purchased from commercial sources and used without further purification. NMR spectra were recorded on a Bruker Fourier (300 Mhz), Bruker Avance I (400 Mhz) and on a Mercury (400 Mhz). Chemical shifts were reported as δ values (ppm). Coupling constants J are reported in Hertz (Hz). Internal reference for NMR spectra is in respect to TMS at 0.0 ppm. Multiplicities are reported, using the standard abbreviations, as follows: singlet (s), doublet (d), triplet (t), quartet (q), doublet of doublets (dd), broad signal (bs), doublet of triplets (dt), triplet of doublets (td), quartet of doublets (qd), multiplet (m), apparent triplet (at).NMR spectra were analyzed using the MestreNova software (version 6.0.2-5475). IR spectra were recorded on a Thermo Scientific NICOLET iS10 by ATR method using neat compounds. The wavelengths are reported in reciprocal centimeters ( /cm -1 ). HRMS spectra were acquired on a Bruker MicroTOF-II spectrometer. Melting points were determined on a Fisher-Johns melting point apparatus and are uncorrected. Reaction progress was monitored by thin layer chromatography (TLC) using silica gel 60 F254 from Merck and the spots were visualized under UV light at 254 or 365 nm. Column chromatography was performed using silica gel (230-400 mesh). Chemical names and drawings were obtained using ChemDraw Professional (version 15.0.0.106). S2General procedure for compounds 16a-l (GP1)Propargylamine (1.0 equiv.) and aldehyde (1.0 equiv.) were placed on a 5 mL round bottom flask and reacted for 5 min, then isocyanide (1.0 equiv.) and TMSN3 (1.3 equiv.) were sequentially added. The reaction mixture was stirred at room temperature for 24 h. Then, the reaction crude was purified by flash column chromatography with Hexane:EtOAc 7:3 (v/v) to afford the 1,5-DS-T 16a-l.Based on the GP1, propargylamine (11.6 µL, 0.18 mmol), 2-fluorobenzaldehyde (19.0 µL, 0.18 mmol), TMSN3(30.9 µL, 0.23 mmol) and tert-butyl isocyanide (20.5 µL, 0.18 mmol) were used and 16a was obtained as a yellow oil (yield 47.9 mg, 92%).

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