Samarium(III) nitrate-catalyzed one-pot synthesis of 42-membered N,S,O-containing cyclophanes

An effective one-pot method for the synthesis of N-aryl-substituted 1,15,29-trioxa6,10,20,24,34,38-hexathia-8,22,36-triaza[1.5.1.5.1.5]paracyclophanes by Sm(NO3)36H2Ocatalyzed heterocyclization of N,N-bis(methoxymethyl)-N-arylamines with 4,4′-dimercaptodiphenyl oxide has been developed. The structural features of the obtained N,S,O-containing cyclophanes have been studied.

The IR spectrum of 3a shows the characteristic absorption band of the CS group (680 cm -1 ), ether group COC (1237 cm -1 ) and CN group (1383 cm -1 ).The molecular ion [M-H] + with m/z 1156.225 was observed in the MALDI-TOF mass spectrum (HCCA matrix), confirming the structure of paracyclophane 3a.
For compound 3a (Figure 1), crystals were obtained from a C 6 H 12 : EtOAc = 5 : 1 solvent mixture by slow evaporation at room temperature.A crystal was studied by X-ray diffraction.According to the X-ray diffraction data, the paracyclophane 3а has a threefold symmetry axis.The highly symmetric structure of 3а consists of three repeating phenylsulfanylmethylaminomethylsulfanylphenol moieties, which form the cyclophane cavity.In the crystalline state, an endocyclic arrangement of the N-aryl substituents with syn-oriented chlorine atoms is observed.The oxodibenzene moiety has pseudo-perpendicular phenyl groups, the angle between the planes being 107.46º.The molecules of compound 3а form crystals with a trigonal crystal lattice.In the crystal, these molecules form stacks along the с axis corresponding to a crystallographic direction.It is noteworthy that adjacent stacks overlap near the phenylsulfanylmethylaminomethylsulfanylphenol moieties (Figure 2).

Experimental Section
General.All reactions were performed at room temperature under an air atmosphere in a round bottom flask equipped with a magnetic stir bar.The 1 H and 13 C NMR spectra were recorded on a Bruker Avance-400 spectrometer (400 and 100 MHz, respectively) in CDCl 3 , internal standard was TMS.Two-dimensional homonuclear (COSY, NOESY) and heteronuclear (HSQC, HMBC) experiments were carried out under Bruker standard procedures at the same operating frequencies.The mixing time for the NOESY experiments was 0.3 s.Mass spectra were recorded on a Bruker Autoflex III MALDI TOF/TOF instrument with α-cyano-4-hydroxycinnamic acid as a matrix.Samples of the compounds were prepared by the "dried droplet method".Elemental analysis was carried out on a Carlo Erba 1106 analyzer.The content of S, Cl and Br was determined by the Shenigers method. 48Melting points were determined on a PHMK 80/2617 apparatus.The progress of reactions was monitored by TLC on Sorbfil (PTSKh-AF-V) plates, eluent was C 6 H 12 : EtOAc, 5:1 (compounds 3 a-g), visualization with I 2 vapour.For column chromatography, silica gel KSK (100-200 μm) was used.Single crystals of 3а was grown from C 6 H 12 : EtOAc, 5:1 solution at room temperature.Data were recorded on a XCalibur Eos diffractrometer (graphite monochromated Mo Kα radiation, λ = 0.71073 Å, ω-scan technique).Crystallographic details of cell data, data collection and refinement are summarized in Table .Collection and processing of data performed with using the program CrysAlisPro Oxford Diffraction Ltd., Version 1.171.36.20.Structure solution and refinement were performed with SHELX. 49The structure was refined by a full-matrix leastsquare technique using anisotropic thermal parameters for non-hydrogen atoms.Crystallographic data for the structures of 3a have been deposited in the Cambridge Crystallographic Data Centre as a CIF deposition with file number CCDC-1430901.Copies of these data can be obtained free of charge on application to CCDC, 12, Union Road, Cambridge, CB2 1EZ, UK (fax: +44 1223 336033, e-mail: deposit@ccdc.cam.ac.uk) or from http://www.ccdc.cam.ac.uk/data_request/cif.
6H 2 O (0.05 mmol) were stirred under argon for 30 min at room temperature, then solution of 4,4′-dimercaptodiphenyl oxide (1.00 mmol) in 1 mL of CH 2 Cl 2 was added.The choice of solvent was determined by the solubility of N,N-bis(methoxymethyl)-N-arylamines 1a-g (CH 2 Cl 2 for 1 a,f,g; EtOAc + CH 2 Cl 2 for 1 b,c; EtOAc + EtOH for 1 d; EtOAc for 1e). 46The reaction mixture was stirred ~ 20 о С for 7 h and concentrated, and the residue was purified by column chromatography on SiO 2 to isolate pure heterocyclic product.

Figure 1 .
Figure 1.Geometry of the structure of 3а with atoms represented by the thermal vibration ellipsoids (p=50%) (left) and by the van der Waals radii (right).

Figure 2 .
Figure 2. The packing arrangement of 3а with atoms represented by the thermal vibration ellipsoids (p=50%) (left) and by the van der Waals radii (right).

Table .
Crystal data and structure refinement for 3a