meso-(1S*,21R*)-25-Methyl-8,11,14-trioxa-22,24,25-triazatetracyclo[19.3.1.02,7.015,20]pentacosa-2,4,6,15(20),16,18-hexaene-23-thione chloroform monosolvate

The title compound crystallizes as a chloroform solvate, C20H23N3O3S·CHCl3, with two crystallographically independent units. The independent units have distinctly different interaction patterns between the azacrown macrocycle and the chloroform solvent molecule. In one of them, the chloroform molecule forms C—H⋯N and Cl⋯H—C hydrogen bonds with the azacrown macrocycle (as a proton donor and an acceptor, respectively), whereas in the other, one of the chloroform molecules is bound to the azacrown macrocycle by an attractive Cl⋯O [3.080 (3) Å] interaction. The azacrown macrocycles of different units are structurally similar; the aza-14-crown-3-ether ring adopts a bowl conformation with dihedral angles between the planes of the fused benzene rings of 60.7 (1) and 68.0 (1)°. The triazinanethione ring in both cases has a sofa conformation. The crystal packing is characterized by N—H⋯S, N—H⋯O, C—H⋯Cl and C—H⋯S hydrogen bonds.

The title compound crystallizes as a chloroform solvate, C 20 H 23 N 3 O 3 SÁCHCl 3 , with two crystallographically independent units. The independent units have distinctly different interaction patterns between the azacrown macrocycle and the chloroform solvent molecule. In one of them, the chloroform molecule forms C-HÁ Á ÁN and ClÁ Á ÁH-C hydrogen bonds with the azacrown macrocycle (as a proton donor and an acceptor, respectively), whereas in the other, one of the chloroform molecules is bound to the azacrown macrocycle by an attractive ClÁ Á ÁO [3.080 (3) Å ] interaction. The azacrown macrocycles of different units are structurally similar; the aza-14-crown-3-ether ring adopts a bowl conformation with dihedral angles between the planes of the fused benzene rings of 60.7 (1) and 68.0 (1) . The triazinanethione ring in both cases has a sofa conformation. The crystal packing is characterized by N-HÁ Á ÁS, N-HÁ Á ÁO, C-HÁ Á ÁCl and C-HÁ Á ÁS hydrogen bonds.
In an attempt to apply these for a synthesis of a macrocyclic ligand with an N-methylsubstituted perhydrotriazine moiety, we studied the multicomponent condensation of thiourea with 1,5-bis(2-formylphenoxy)-3-oxapentane and methylammonium acetate. The reaction has proceeded smoothly under mild conditions to give the expected azacrown moiety in a good yield ( Figure 1).
The molecule of I possesses two asymmetric centers at the C1 and C21 carbon atoms and represents a meso-form (an internal racemate).
In the crystal, the molecular I.CHCl 3 associates are linked by the intermolecular N-H···S, N-H···O, C-H···Cl and C -H···S hydrogen bonds into a three-dimensional framework (

Experimental
Methylamine ammonium acetate (4.0 g, 44 mmol) was added to a solution of 1,5-bis(2-formylphenoxy)-3-oxapentane (1.57 g, 5.0 mmol) and thiourea (0.38 g, 5.0 mmol) in a mixture of ethanol (30 ml) and acetic acid (1 ml). The reaction mixture was stirred at 293 K for 3 days. At the end of the reaction, the formed precipitate was filtered off, washed with ethanol and re-crystallized from ethanol and ethylacetate (4:1) to give 1.19 g of white crystals of I. Yield is 61.8%. M.p. = 417-419 K. IR (KBr), ν/cm -1 : 1603, 3215, 3332. 1 HNMR (DMSO-d 6 , 400 MHz, 300 K): δ = 1.53 (s, 3H, CH 3 ), 3.63 and 3.92 (both m, 3H and 5H, respectively, OCH 2 CH 2 OCH 2 CH 2 O), 6.21 (s, 2H, H1 and H21), 6.87 (      Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq S1 0.40501 (