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Journal of Chemistry
Volume 2016 (2016), Article ID 8406172, 6 pages
http://dx.doi.org/10.1155/2016/8406172
Research Article

New Catalytic Method for the Synthesis of 2,7-Dicycloalkyl-hexaazaperhydropyrenes

Institute of Petrochemistry and Catalysis, Russian Academy of Sciences, 141 Prospekt Oktyabrya, Ufa 450075, Russia

Received 9 October 2016; Accepted 24 November 2016

Academic Editor: Gabriel Navarrete-Vazquez

Copyright © 2016 Elena Rakhimova et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

An efficient method for the synthesis of 2,7-dicycloalkyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrenes by the NiCl2·6H2O-catalyzed ring transformation reaction of 1,3,5-tricycloalkyl-1,3,5-triazines with 1,4,5,8-tetraazadecalin has been successfully developed.

1. Introduction

The interest in diazapyrenes is related to their practical applicability as drug candidates for the development of analgesics [1] and antibacterial [2] and antitumor [3, 4] drugs agents. Polyazapyrenes are actively used in supramolecular chemistry for the design of molecular devices [5], host-guest type molecules [6], and macrocyclic squares incorporating mixed transition metal systems and a main group element [7]. Currently, quite a number of isomeric diazapyrenes [8] and polyazapyrenes [9] with different arrangements of the peripheral nitrogen atoms in the pyrene ring have been synthesized. As previously reported [10], 2,7-diazapyrenes can be obtained by the reaction of dihydroazaphenalene with sym-triazine in polyphosphoric acid. There is little information about methods for the synthesis of azaperhydropyrenes. For instance, stereoisomeric tetraazaperhydropyrenes can be synthesized by the reaction of 1,4,5,8-tetraazadecalin with methyl acrylate [11]. Hexaazaperhydropyrenes are prepared by the three-component cyclocondensation of amines with formaldehyde and 1,4,5,8-tetraazadecalin in the presence of a strong acid cation exchanger [12] or by the intermolecular heterocyclization of 1,4,5,8-tetraazadecalin with N,N-bis(methoxymethyl)-N-alkylamines in the presence of the lanthanide catalyst [13].

Herein, we report a new efficient synthesis of 2,7-dicycloalkyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrenes through the ring transformation reaction of 1,3,5-tricycloalkyl-1,3,5-triazines with 1,4,5,8-tetraazadecalin catalyzed by NiCl2·6H2O.

2. Materials and Methods

The NMR spectra, including two-dimensional homonuclear (COSY and NOESY) and heteronuclear (HSQC and HMBC) spectra, were recorded on a Bruker Avance 500 spectrometer at 500.17 MHz for 1H and 125.78 MHz for 13C according to standard Bruker procedures. CDCl3 was used as the solvent, and tetramethylsilane was used as the internal standard. The MALDI TOF/TOF mass spectra (positive ion detection, 2,5-dihydroxybenzoic acid matrix) were obtained on a Bruker AutoflexTM III Smartbeam mass spectrometer. Samples were prepared by the dried drop technique. Solutions of matrix and substrate were mixed at a ratio of 50 : 1 to 100 : 1, and a drop of the mixture was applied onto a target and dried in a stream of warm air. The sample was vaporized from the target by laser pulses (200 pulses with a frequency of 100 Hz) generated by a solid state UV laser (λ 355 nm). The elemental analyses were obtained on a Carlo Erba 1106 analyzer. The melting points were determined on a PHMK 80/2617 melting point apparatus. The reaction progress was controlled by TLC using Sorbfil plates (PTSH-AF-V); spots were visualized by treatment with iodine vapor. Column chromatography was performed on KSK silica gel (100–200 μm). 1,4,5,8-Tetraazadecalin (1) was obtained as described previously [14].

Ring Transformation Reaction of 1,3,5-Tricycloalkyl-1,3,5-triazines with 1,4,5,8-Tetraazadecalin (1) (General Method). A round bottom flask equipped with a magnetic stir bar was charged with MeOH (10 mL), the corresponding 1,3,5-tricycloalkyl-1,3,5-triazine (2.00 mmol), obtained in situ by the reported procedure [15], and NiCl2·6H2O (0.012 g, 0.05 mmol). The mixture was stirred at room temperature for 30 min. Next, 1,4,5,8-tetraazadecalin (1) (0.14 g, 1.00 mmol) in H2O (1 mL) was added to the mixture. The mixture was stirred at 20°C for 3 h and evaporated. The residue was separated by column chromatography on silica gel (SiO2) with MeOH as the eluent. Compounds 28 were obtained as colorless crystals (recrystallized from MeOH). The final products 28 were identified by spectral methods.

2,7-Dicyclopropyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrene (2). = 0.63 (MeOH); m.p. = 195–197°C; 1H NMR (500.17 MHz, CDCl3): = 0.45 (d, 3Jab = 3 Hz, 4H; CH2; Ha-2′, 2′′, 3′, 3′′), 0.53 (d, 3Jab = 6 Hz, 4H; CH2; Hb-2′, 2′′, 3′, 3′′), 2.32 (br.s., 2H; CH; H-10b, 10c), 2.35 (d, 3Jab = 7 Hz, 4H; CH2; Ha-4, 5, 9, 10), 2.56–2.59 (m, 2H; CH; H-1′, 1′′), 2.63 (d, 3Jba = 7 Hz, 4H; CH2; Hb-4, 5, 9, 10), 3.10 (d, 2Jab = 10 Hz, 4H; CH2; Ha-1, 3, 6, 8), 3,77 ppm (d, 2Jba = 10 Hz, 4H; CH2; Hb-1, 3, 6, 8); 13C NMR (125.78 MHz, CDCl3): = 6.8 (C-2′, C-2′′, C-3′, C-3′′), 33.5 (C-1′, C-1′′), 48.1 (C-4, C-5, С-9, С-10), 74.4 (C-1, C-3, C-6, C-8), 82.7 ppm (C-10b, C-10c); MS (MALDI TOF/TOF): m/z (%): 303 (100) [M+−H]; elemental analysis calcd (%) for C16H28N6: С 63.12; H 9.27; N 27.61; found: С 63.06; H 9.22; N 27.54.

2,7-Dicyclopentyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrene (3). = 0.65 (MeOH); m.p. = 224–226°C; 1H NMR (500.17 MHz, CDCl3): = 1.33–1.41 (m, 4H; CH2; Ha-2′, 2′′, 5′, 5′′), 1.58–1.62 (m, 4H; CH2; Ha-3′, 3′′, 4′, 4′′), 1.70–1.73 (m, 4H; CH2; Hb-3′, 3′′, 4′, 4′′), 1.88–1.91 (m, 4H; CH2; Hb-2′, 2′′, 5′, 5′′), 2.72 (br.s., 2H; CH; H-10b, 10c), 2.33 (d, 3Jab = 7 Hz, 4H; CH2; Ha-4, 5, 9, 10), 2.57 (d, 3Jba = 7 Hz, 4H; CH2; Hb-4, 5, 9, 10), 2.97 (d, 2Jab = 10 Hz, 4H; CH2; Ha-1, 3, 6, 8), 3.27–3.34 (m, 2H; CH; H-1′, 1′′), 3.79 ppm (d, 2Jba = 10 Hz, 4H; CH2; Hb-1, 3, 6, 8); 13C NMR (125.78 MHz, CDCl3): = 23.9 (C-3′, C-3′′, C-4′, C-4′′), 31.3 (C-2′, C-2′′, C-5′, C-5′′), 48.2 (C-4, C-5, С-9, С-10), 60.2 (C-1′, C-1′′), 73.6 (C-1, C-3, С-6, С-8), 82.5 ppm (C-10b, C-10c); MS (MALDI TOF/TOF): m/z (%): 359 (100) [M+−H]; elemental analysis calcd (%) for C20H36N6: С 66.63; H 10.06; N 23.31; found: С 66.56; H 10.02; N 23.24.

2,7-Dicyclohexyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrene (4). = 0.71 (MeOH); m.p. = 225–227°C; 1H NMR (500.17 MHz, CDCl3): = 1.13–1.18 (m, 6H; CH2; Ha-2′, 2′′, 4′, 4′′, 6′, 6′′), 1.25–1.31 (m, 4H; CH2; Ha-3′, 3′′, 5′, 5′′), 1.63 (br.s., 2H; CH2; Hb-4′, 4′′), 1.77 (d, 2Jba = 12 Hz, 4H; CH2; Hb-3′, 3′′, 5′, 5′′), 1.99 (d, 2Jba = 10 Hz, 4H; CH2; Hb-2′, 2′′, 6′, 6′′), 2.25 (br.s., 2H; CH; H-10b, 10с), 2.30 (d, 3Jab = 7 Hz, 4H; CH2; Ha-4, 5, 9, 10), 2.55 (d, 3Jba = 7 Hz, 4H; CH2; Hb-4, 5, 9, 10), 2.82 (br.s., 2H; CH; H-1′, 1′′), 2.99 (d, 2Jab = 10 Hz, 4H; CH2; Ha-1, 3, 6, 8), 3.84 ppm (d, 2Jba = 10 Hz, 4H; CH2; Hb-1, 3, 6, 8); 13C NMR (125.78 MHz, CDCl3): = 25.3 (C-3′, C-3′′, C-5′, C-5′′), 26.0 (C-4′, C-4′′), 30.7 (C-2′, C-2′′, C-6′, C-6′′), 48.2 (C-4, C-5, С-9, С-10), 57.1 (C-1′, C-1′′), 71.3 (C-1, C-3, С-6, С-8), 82.7 ppm (C-10b, C-10c); MS (MALDI TOF/TOF): m/z (%): 387 (100) [M+−H]; elemental analysis calcd (%) for C22H40N6: С 68.00; H 10.37; N 21.63; found: С 67.92; H 10.32; N 21.55.

2,7-Ditetrahydropyran-4-yl-2,3a,5a,7,8a,10a-hexaazaperhydropyrene (5). = 0.47 (MeOH); m.p. = 241–243°C; 1H NMR (500.17 MHz, CDCl3): = 1.46–1.50 (m, 4H; CH2; Ha-2′, 2′′, 6′, 6′′), 1.88 (d, 2Jba = 12 Hz, 4H; CH2; Hb-2′, 2′′, 6′, 6′′), 2.26–2.29 (m, 4H; CH2; Ha-4, 5, 9, 10; 2H, CH; H-10b, 10с), 2.53 (d, 3Jba = 7 Hz, 4H; CH2; Hb-4, 5, 9, 10), 3.07 (d, 2Jab = 10 Hz, 4H; CH2; Hb-1, 3, 6, 8), 3.17–3.19 (m, 2H; CH; H-1′, 1′′), 3.41–3.47 (m, 4H; CH2; Ha-3′, 3′′, 5′, 5′′), 3.82 (d, 2Jba = 10 Hz, 4H; CH2; Hb-1, 3, 6, 8), 4.00 ppm (d, 2Jba = 10 Hz, 4H; CH2; Hb-3′, 3′′, 5′, 5′′); 13C NMR (125.78 MHz, CDCl3): = 31.3 (C-2′, C-2′′, C-6′, C-6′′), 48.0 (C-4, C-5, C-9, C-10), 54.0 (C-1′, C-1′′), 67.0 (C-3′, С-3′′, C-5′, С-5′′), 70.6 (C-1, C-3, С-6, С-8), 82.7 ppm (C-10b, C-10c); elemental analysis calcd (%) for C20H36N6O2: С 61.19; H 9.25; N 21.41; O 8.15; found: С 61.08; H 9.20; N 21.32.

2,7-Dicycloheptyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrene (6). = 0.75 (MeOH); m.p. = 229–231°C; 1H NMR (500.17 MHz, CDCl3): = 1.40–1.43 (m, 4H; CH2; Ha-3′, 3′′, 6′, 6′′), 1.52–1.55 (m, 12H; CH2; H-4′, 4′′, 5′, 5′′, Ha-2′, 2′′, 7′, 7′′), 1.60–1.65 (m, 4H; CH2; Hb- Hb-3′, 3′′, 6′, 6′′), 1.86–1.91 (m, 4H; CH2; Hb-2′, 2′′, 7′, 7′′), 2.24 (br.s., 2H; CH; H-10b, 10с), 2.34 (d, 3Jab = 7 Hz, 4H; CH2; Ha-4, 5, 9, 10), 2.58 (d, 3Jba = 7 Hz, 4H; CH2; Hb-4, 5, 9, 10), 2.91–2.92 (m, 2H; CH; H-1′, 1′′), 2.95 (d, 2Jab = 10 Hz, 4H; CH2; Ha-1, 3, 6, 8), 3.76 ppm (d, 2Jba = 10 Hz, 4H; CH2; Ha-1, 3, 6, 8); 13C NMR (125.78 MHz, CDCl3): = 24.7 (C-3′, C-3′′, C-6′, C-6′′), 28.4 (C-4′, C-4′′, C-5′, C-5′′), 31.3 (C-2′, C-2′′, C-7′, C-7′′), 48.4 (C-4, C-5, С-9, С-10), 60.2 (C-1′, C-1′′), 71.8 (C-1, C-3, С-6, С-8), 82.6 ppm (C-10b, C-10c); MS (MALDI TOF/TOF): m/z (%): 455 (100) [M++К], 439 (30) [M++Na], 415 (90) [M+–H]; elemental analysis calcd (%) for C24H44N6: С 69.18; H 10.65; N 20.17; found: С 69.09; H 10.60; N 20.08.

2,7-Dicyclooctyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrene (7). = 0.75 (MeOH); m.p. = 230–232°C; 1H NMR (500.17 MHz, CDCl3): = 1.45–1.49 (m, 10H; CH2; Ha-3′, 3′′, 4′, 4′′, 5′, 5′′, 6′, 6′′, 7′, 7′′), 1.51–1.61 (m, 10H; CH2; Ha-2′, 2′′, 8′, 8′′; Hb-3′, 3′′, 5′, 5′′, 7′, 7′′), 1.70–1.73 (m, 4H; CH2; Hb- Hb-4′, 4′′, 6′, 6′′), 1.81–1.85 (m, 4H; CH2; Hb-2′, 2′′, 8′, 8′′), 2.24 (br.s., 2H; CH; H-10b, 10с), 2.34 (d, 3Jab = 7 Hz, 4H; CH2; Ha-4, 5, 9, 10), 2.57 (d, 3Jba = 7 Hz, 4H; CH2; Hb-4, 5, 9, 10), 2.94 (d, 2Jab = 10 Hz, 4H; CH2; Ha-1, 3, 6, 8), 2.98–2.99 (m, 2H; CH; H-1′, 1′′), 3.76 ppm (d, 2Jba = 10 Hz, 4H, CH2; Hb-1, 3, 6, 8); 13C NMR (125.78 MHz, CDCl3): = 24.5 (C-4′, C-4′′, C-6′ C-6′′), 26.1 (C-5′, C-5′′), 27.2 (C-3′, C-3′′, C-7′, C-7′′), 29.2 (C-2′, C-2′′, C-8′, C-8′′), 48.4 (C-4, C-5, С-9, С-10), 58.4 (C-1′, C-1′′), 71.9 (C-1, C-3, С-6, С-8) 82.6 ppm (C-10b, C-10c); MS (MALDI TOF/TOF): m/z (%): 483 (100) [M++К], 467 (30) [M++Na], 443 (90) [M+–H]; elemental analysis calcd (%) for C26H48N6: С 70.22; H 10.88; N 18.90; found: С 70.14; H 10.81; N 18.83.

2,7-Dibi[2.2.1]hept-2-yl-2,3a,5a,7,8a,10a-hexaazaperhydropyrene (8). = 0.75 (MeOH); m.p. = 261–263°C; 1H NMR (500.17 MHz, CDCl3): = 1.05–1.12 (m, 6H; CH2; Ha-3′, 3′′, 6′, 6′′, 7′, 7′′), 1.41–1.55 (m, 10H; CH2; Hb-3′, 3′′, 6′, 6′′, 7′, 7′′; H-5′, 5′′), 2.25 (br.s., 4H; CH; H-10b, 10с, 4′, 4′′), 1.77 (d, 2Jba = 12 Hz, 4H; CH2; Hb-3′, 3′′, 5′, 5′′), 1.99 (d, 2Jba = 10 Hz, 4H; CH2; Hb-2′, 2′′, 6′, 6′′), 2.25 (br.s., 2H; CH; H-10b, 10с), 2.33 (br.s., 2H; CH; Н-2′, 2′′; 4H, CH2; Ha-4, 5, 9, 10), 2.58 (d, 3Jba = 7 Hz, 4H; CH2; Hb-4, 5, 9, 10), 2.68–2.70 (m, 2H; CH; H-1′, 1′′), 2.71–2.78 (m, 4H; CH2; Ha-1, 3, 6, 8), 3.81–3.84 ppm (m, 4H; CH2; Hb-1, 3, 6, 8); 13C NMR (125.78 MHz, CDCl3): = 27.5 (C-6′ C-6′′), 28.5 (C-7′, C-7′′), 35.0 (C-3′ C-3′′), 36.2 (C-4′, C-4′′), 37.6 (C-5′, C-5′′), 38.2 (C-2′, C-2′′), 48.3 (C-4, C-5, С-9, С-10), 62.7 (C-1′, C-1′′), 72.7 (C-1, C-3, С-6, С-8) 82.4 ppm (C-10b, C-10c); elemental analysis calcd (%) for C24H40N6: С 69.86; H 9.77; N 20.37; found: С 69.77; H 9.71; N 20.29.

3. Results and Discussion

To develop a new preparative method for the synthesis of 2,7-dicycloalkyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrenes, which are difficult to obtain by other methods, we have studied the ring transformations in the reaction of 1,3,5-tricycloalkyl-1,3,5-triazines with 1,4,5,8-tetraazadecalin (1). 1,3,5-Triazine was chosen as a new aminomethylating reagent for the synthesis of target hexaazaperhydropyrenes resorting to the reported [16] ring transformation reaction of 1,3,5-triazin-2-one induced by compounds having active hydrogen atoms (S–H). 1,4,5,8-Tetraazadecalin was hypothesized to serve as a compound containing active N–H bonds by analogy with 1,2-ethanedithiol used in the ring transformation of 1,3,5-triazin-2-one [16].

Our preliminary experiments have shown that noncatalyzed reaction of in situ generated 1,3,5-tricyclopropyl-1,3,5-triazine [15] with 1,4,5,8-tetraazadecalin at 20°С in MeOH afforded 2,7-dicyclopropyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrene (2) in no more than 10% yield. Conducting the reaction in refluxing methanol increased the yield of hexaazaperhydropyrene to 35%.

To achieve a higher yield of the target heterocycle 2, we have performed the reaction of 1,3,5-tricyclopropyl-1,3,5-triazine with 1,4,5,8-tetraazadecalin in the presence of the catalysts that showed high activity in the ring transformation reactions [1719]. The highest activity was found for catalysts based on transition metal salts and complexes, the yield of 2,7-dicyclopropyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrene (2) being increased in the series of catalysts (5 mol% toward tetraazadecalin) as follows: Pd[CH3COO]2 (41%), PdCl2 (44%), CuCl2·6H2O (65%), Cp2TiCl2 (73%), PtCl2 (75%), FeCl3·6H2O (78%), CoCl2·6H2O (82%), and NiCl2·6H2O (89%). When lanthanide (Er, Sm, Yb, La, In, and Eu) salts were used as the catalysts, the yield of hexaazaperhydropyrenes (2) did not exceed 70%. All experiments were carried out in MeOH at room temperature (~20°С) due to good solubility of the reactants and the target heterocycles.

Under optimized reaction conditions (5 mol% NiCl2·6H2O, 20°С, 3 h, MeOH), 1,3,5-tricycloalkyl-1,3,5-triazines react with 1,4,5,8-tetraazadecalin (1) to afford selectively 2,7-dicycloalkyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrenes 28 in 74–89% yield (Scheme 1).

Scheme 1: The ring transformation reaction of 1,3,5-tricycloalkyl-1,3,5-triazines with 1,4,5,8-tetraazadecalin.

In the 1Н NMR spectra (Figure 1) of compounds 28, characteristic signals are doublets at 2.71–3.10 and 3.76–3.84 ppm (J = 10 Hz, geminal) corresponding to the methylene protons (H-1, H-3, H-6, and H-8) at the carbon atoms located between two nitrogen atoms. The methylene protons (H-4, H-5, H-9, and H-10) resonate as two doublets at 2.26–2.63 ppm (J = 7 Hz, vicinal). The broadened signals at 2.24–2.72 ppm belong to the cage protons (H-10b and H-10c).

Figure 1: 1Н NMR spectra of compound 4.

The hexaazaperhydropyrene cage of compounds 28 is responsible for three 13С NMR (Figure 2) signals at 48.0–48.4, 70.6–74.4, and 82.4–82.7 ppm with a 2 : 2 : 1 integrated intensity ratio. The signals were assigned based on homonuclear (COSY and NOESY) and heteronuclear (HSQC and HMBC) 2D NMR experiments.

Figure 2: 13С NMR spectra of compound 4.

The proposed structures were confirmed by the molecular ion peaks present in the positive ion matrix assisted laser desorption ionization tandem time-of-flight mass spectra (MALDI TOF/TOF MS, resolution 0.001 a.u.).

The experimental results as well as published data suggest [2023] that the ring transformation reaction of 1,3,5-tricycloalkyl-1,3,5-triazine with tetraazadecalin 1 represents a multistaged chemical process. It comprises the successive steps of coordination of the tertiary nitrogen atom to the catalyst central ion, ring opening of the starting heterocycle, nucleophilic addition of secondary amine to a carbocation, and subsequent intermolecular cyclization to give the target hexaazaperhydropyrenes (Scheme 2). The GC/MS analysis of the reaction products formed from 1,3,5-tricyclohexyl-1,3,5-triazine and tetraazadecalin 1 showed the fragment ion at m/z 127 [M-C6H11] formed upon fragmentation of N,N-dicyclohexylmethanediamine [CH2(NH-cyclo-C6H11)2], resulting from ring transformation of 1,3,5-tricyclohexyl-1,3,5-triazine, which provides evidence for the proposed reaction pathway.

Scheme 2: The possible reaction pathway.

4. Conclusion

Polyheterocyclic structural architectures occur in many bioactive natural products and synthetic drugs, and these structural units serve as important intermediates in organic synthesis. Therefore, organic chemists have been making extensive efforts to produce polyheterocyclic compounds by developing new and efficient synthetic transformations. Among the variety of new synthetic transformations, catalyzed reactions are some of the most attractive methodologies for synthesizing polyheterocycles. In summary, we have developed an efficient method for the synthesis of 2,7-dicycloalkyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrenes, difficult to prepare previously, via the NiCl2·6H2O-catalyzed ring transformation reaction of 1,3,5-tricycloalkyl-1,3,5-triazines with 1,4,5,8-tetraazadecalin.

Competing Interests

The authors declare that there are no competing interests regarding the publication of this paper.

Acknowledgments

This work was financially supported by the Russian Foundation for Basic Research (Grants 14-03-00240, 14-03-97023, and 16-29-10687) and President of Russian Federation for Government Support of Leading Scientific Schools (Grant SS-6651.2016.3). The structural studies of compounds 28 were performed with the use of Collective Usage Centre “Agidel” at the Institute of Petrochemistry and Catalysis of RAS.

References

  1. I. V. Borovlev and O. P. Demidov, “Diazapyrenes,” Chemistry of Heterocyclic Compounds, vol. 39, no. 11, pp. 1417–1442, 2003. View at Publisher · View at Google Scholar · View at Scopus
  2. I. V. Borovlev and O. P. Demidov, “Synthesis of aza-and polyazapyrenes (Review),” Chemistry of Heterocyclic Compounds, vol. 44, no. 11, pp. 1311–1327, 2008. View at Publisher · View at Google Scholar · View at Scopus
  3. A. V. Aksenov, I. V. Borovlev, I. V. Aksenova, S. V. Pisarenko, and D. A. Kovalev, “A new method for [c,d]pyridine peri-annelation: synthesis of azapyrenes from phenalenes and their dihydro derivatives,” Tetrahedron Letters, vol. 49, no. 4, pp. 707–709, 2008. View at Publisher · View at Google Scholar · View at Scopus
  4. M. Antoine, H. Bernard, N. Kervarec, and H. Handel, “Synthesis and NMR characterisation of new cyclam-glyoxal diamides,” Journal of the Chemical Society, Perkin Transactions 2, vol. 2, no. 3, pp. 552–555, 2002. View at Google Scholar · View at Scopus
  5. P. Neumann, A. Aumueller, and H. Trauth, US Pat. 4904779, Chem. Abstr., 112, P35899h, 1990.
  6. E. B. Rakhimova, R. A. Ismagilov, E. S. Meshcheryakova, L. M. Khalilov, A. G. Ibragimov, and U. M. Dzhemilev, “An efficient catalytic method for the synthesis of 2,7-dialkyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrenes,” Tetrahedron Letters, vol. 55, no. 46, pp. 6367–6369, 2014. View at Publisher · View at Google Scholar · View at Scopus
  7. A. D. Andricopulo, L. A. Müller, V. C. Filho et al., “Analgesic activity of cyclic imides: 1,8-naphthalimide and 1,4,5,8-naphthalenediimide derivatives,” Il Farmaco, vol. 55, no. 4, pp. 319–321, 2000. View at Publisher · View at Google Scholar · View at Scopus
  8. S. G. Wakeham, “Azaarenes in recent lake sediments,” Environmental Science & Technology, vol. 13, no. 9, pp. 1118–1123, 1979. View at Publisher · View at Google Scholar · View at Scopus
  9. S. Roknić, L. Glavaš-Obrovac, I. Karner, I. Piantanida, M. Žinić, and K. Pavelić, “In vitro cytotoxicity of three 4,9-diazapyrenium hydrogensulfate derivatives on different human tumor cell lines,” Chemotherapy, vol. 46, no. 2, pp. 143–149, 2000. View at Publisher · View at Google Scholar · View at Scopus
  10. I. Steiner-Biocic, L. Glavaš-Obrovac, I. Karner et al., “4,9-diazapyrenium dications induce apoptosis in human tumor cells,” Anticancer Research, vol. 16, no. 6, pp. 3705–3708, 1996. View at Google Scholar · View at Scopus
  11. V. Balzani, S. J. Langford, F. M. Raymo, J. Fraser Stoddart, and M. Venturi, “Constructing molecular machinery: a chemically-switchable [2]Catenane,” Journal of the American Chemical Society, vol. 122, no. 14, pp. 3542–3543, 2000. View at Publisher · View at Google Scholar · View at Scopus
  12. J. Jazwinski, A. J. Blacker, J.-M. Lehn, M. Cesario, J. Guilhem, and C. Pascard, “Cyclo-bisintercalands: synthesis and structure of an intercalative inclusion complex, and anion binding properties,” Tetrahedron Letters, vol. 28, no. 48, p. 6060, 1987. View at Publisher · View at Google Scholar · View at Scopus
  13. P. J. Stang, B. Olenyuk, J. Fan, and A. M. Arif, “Combining ferrocenes and molecular squares: Self-assembly of heterobimetallic macrocyclic squares incorporating mixed transition metal systems and a main group element. Single-crystal X-ray structure of [Pt(dppf)(H2O)2][OTf]2,” Organometallics, vol. 15, no. 3, pp. 904–908, 1996. View at Publisher · View at Google Scholar · View at Scopus
  14. C. Chitwood and R. W. MacNamee, US Pat. 2345237, Chem. Abstr., 38, 4274, 1945.
  15. R. F. Borch and A. I. Hassid, “New method for the methylation of amines,” Journal of Organic Chemistry, vol. 37, no. 10, pp. 1673–1674, 1972. View at Publisher · View at Google Scholar · View at Scopus
  16. U. Wellmar, “Urea as leaving group in the synthesis of 3-(tert-butyl)perhydro-1,5,3-dithiazepine,” Journal of Heterocyclic Chemistry, vol. 35, no. 6, pp. 1531–1532, 1998. View at Publisher · View at Google Scholar · View at Scopus
  17. E. B. Rakhimova, R. A. Ismagilov, E. S. Meshcheryakova et al., “Synthesis of N-hydroxyalkyl-1,5,3-dithiazepanes based on amino alcohols,” Khim Geterotsikl Soedin, vol. 50, no. 5, pp. 782–787, 2014, Chemistry of Heterocyclic Compounds, vol. 50, no. 5, pp. 720–725, 2014 (English). View at Google Scholar
  18. E. B. Rakhimova, E. S. Meshcheryakova, L. M. Khalilov, A. G. Ibragimov, and U. M. Dzhemilev, “Efficient catalytic synthesis of (1,5,3-dithiazepan-3-yl)quinolines,” Zhurnal Organicheskoi Khimii, vol. 50, no. 11, pp. 1627–1630, 2014, English Translation: Russian Journal of Organic Chemistry, vol. 50, no. 11, pp. 1613–1616, 2014. View at Google Scholar
  19. E. B. Rakhimova, R. A. Ismagilov, L. M. Khalilov, R. A. Zainullin, A. G. Ibragimov, and U. M. Dzhemilev, “Efficient catalytic synthesis of N-cycloalkyl-1,5,3-dithiazepanes,” Russian Journal of Organic Chemistry, vol. 51, no. 7, pp. 951–956, 2015. View at Publisher · View at Google Scholar · View at Scopus
  20. S. P. Voronin, T. I. Gubina, S. A. Trushin, I. A. Markushina, and V. G. Kharchenko, “Mechanism of recyclization of furans to thiophenes and selenophenes under acid-catalysis conditions. 2. Kinetic investigations of the reaction of 2,5-dialkylfurans with hydrogen sulfide and hydrogen selenide in an anhydrous medium,” Khim Geterotsikl Soedin, vol. 25, no. 11, pp. 1458–1462, 1989, Chemistry of Heterocyclic Compounds, vol. 25, no. 11, pp. 1216–1220, 1989, (English). View at Google Scholar
  21. G. V. Mokrov, A. M. Likhosherstov, V. P. Lezina, T. A. Gudasheva, I. S. Bushmarinov, and M. Yu. Antipin, “Synthesis and selected properties of N-substituted pyrrolo[2,1-c]-1,3-diazacycloalkano[1,2-a]pyrazinones,” Izvestiya Akademii Nauk, Seriya Khimicheskaya, vol. 59, no. 6, pp. 1228–1239, 2010, Russian Chemical Bulletin, vol. 59, no. 6, pp. 1254–1266, 2010 (English). View at Google Scholar
  22. K. Krohn and S. Cludius-Brandt, “Acid-induced rearrangement reactions of α-hydroxy-1,3-dithianes,” Synthesis, no. 8, pp. 1344–1348, 2010. View at Publisher · View at Google Scholar · View at Scopus
  23. V. Y. Kukushkin and Y. N. Kukushkin, “ChemInform Abstract: Complex boron and aluminum hydrides in preparative coordination chemistry,” ChemInform, vol. 18, no. 3, article 288, 1987. View at Publisher · View at Google Scholar