Microwave-assisted synthesis and myorelaxant activity of 9-indolyl-1,8-acridinedione derivatives.

In this study a microwave-assisted method was applied for the synthesis of novel 9-(substituted indolyl)-3,4,6,7-tetrahydroacridine-1,8-(2H,5H,9H,10H)-dione derivatives. The structures of the compounds were confirmed by spectral methods including X-ray studies and elemental analysis. The Emax and pD2 values of the compounds and pinacidil were determined on noradrenaline precontracted tissues of isolated strips of rabbit gastric fundus smooth muscle. The obtained results indicated that some compounds and pinacidil produced concentration-dependent relaxation on the strips. The efficacy of compound 9 was higher than pinacidil. Docking studies were carried out to understand the interactions of the compounds with the active site of potassium channel. Methyl substituents on the acridine backbone and bromine atom on the indole ring led to more active compounds.

7-Methyl-1-phenyl-1,10-di-hydro-pyrazolo-[3,4-a]carbazole.

In the title mol-ecule, C20H15N3, the atoms in the carbazole unit deviate from planarity [maximum deviation from mean plane = 0.1082 (15) Å]. The pyrrole ring makes dihedral angles of 3.17 (8)/4.10 (9), 7.20 (9) and 44.62 (9)° with the fused benzene, pyrazole and phenyl rings, respectively. In the crystal, mol-ecules are linked via N-H⋯N hydrogen bonds, forming an infinite chain along [010]. Mol-ecules are further linked by nine π-π [centroid-centroid distances vary from 3.6864 (11) to 3.9802 (11) Å] and one C-H⋯π inter-action, forming a three-dimensional network.

catena-Poly[[[O,O'-bis-(2-methyl-phen-yl) dithio-phosphato-κ(2) S,S]lead(II)]-µ-O,O'-bis-(2-methyl-phen-yl) dithio-phosphato-κ(3) S,S':S].

In the title compound, [Pb(C14H14O2PS2)2] n , the metal atom is surrounded by two O,O'-bis-(2-methyl-phen-yl) dithio-phosphate ligands bonding through the S-donor atoms. Three of the Pb-S bond lengths are are close to each other at 2.7710 (18), 2.8104 (16) and 2.8205 (16) Å, while the fourth Pb-S bond is elongated at 3.0910 (18) Šand reflects the fact that this atom is involved in inter-molecular bridging to an adjacent Pb(II) atom [Pb-S = 3.145 (2) Å]. The bond angles demonstrate that the Pb(II) atom contains a stereochemically active lone pair with a distorted octa-hedral geometry about the Pb(II) atom. This distortion is shown by the S-Pb-S bite angles of 73.63 (4) and 69.50 (4)°, while the remaining S-Pb-S angles range from 81.03 (5) to 143.66 (5)°. One of the benzene rings shows positional disorder over two orientations with occupancy factors of 0.747 (11) and 0.253 (11).

Ethyl 2,7,7-trimethyl-4-(1-methyl-1H-indol-3-yl)-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate.

In the title mol-ecule, C24H28N2O3, the cyclo-hexene ring is in a sofa conformation and the 1,4-dihydro-pyridine ring is in a slight boat conformation. In the indole ring system, the pyrrole and benzene rings form a dihedral angle of 2.63 (7)°. In the crystal, N-H⋯O hydrogen bonds connect the mol-ecules into C(6) chains parallel to the b axis and pairs of weak C-H⋯O hydrogen bonds link inversion-related chains into a ladder motif through R2(2)(18) rings. A weak intra-molecular C-H⋯O hydrogen bond is also observed.

2-(1-Phenyl-1H-benzimidazol-2-yl)phenol.

In the title mol-ecule, C19H14N2O, the benzimidazole unit is close to being planar [maximum deviation = 0.0253 (11) Å] and forms dihedral angles of 68.98 (6) and 20.38 (7)° with the adjacent phenyl and benzene rings; the dihedral angle between the latter two planes is 64.30 (7)°. An intra-molecular O-H⋯N hydrogen bond generates an S(6) ring motif. In the crystal, mol-ecules are linked by C-H⋯N and C-H⋯O hydrogen bonds, and consolidated into a three-dimensional architecture by π-π stacking inter-actions, with a centroid-centroid distance of 3.8428 (12) Å.

2,2,7,7-Tetra-methyl-1,2,3,4,5,6,7,8-octa-hydro-acridine-1,8-dione.

The whole molecule of the title compound, C17H21NO2, is generated by twofold rotational symmetry. The N atom and the C and H atoms in position 4 of the pyridine ring lie on the twofold axis. The cyclohexene ring has a sofa conformation with the CH2 C atom adjacent to the dimethyl-substituted C atom displaced by 0.5949 (16) Šfrom the mean plane of the other five C atoms. In the crystal, weak C-H⋯O inter-actions link the mol-ecules into chains parallel to the a axis. In addition, π-π stacking inter-actions [centroid-centroid distance = 3.8444 (7) Å] contribute to the stabilization of the crystal structure.

(E)-2-[(Furan-2-yl)methyl-idene]-7-methyl-2,3,4,9-tetra-hydro-1H-carbazol-1-one.

In the title mol-ecule, C(18)H(15)NO(2), the atoms in the carbazole unit deviate from planarity [maximum deviation from mean plane = 0.1317 (12) Å]. The pyrrole ring makes dihedral angles of 1.01 (8) and 18.56 (10)° with the benzene and furan rings, respectively. The cyclo-hexene ring adopts a half-chair conformation. In the crystal, pairs of N-H⋯O hydrogen bonds form an R(2) (2)(10) ring. Mol-ecules are further linked by C-H⋯O and C-H⋯π inter-actions, forming a three-dimensional network.

2-(4-Fluoro-phen-yl)-1-(4-methyl-phen-yl)-1H-phenanthro[9,10-d]imidazole.

The phenanthrene tricyclic ring system in the title mol-ecule, C(28)H(19)FN(2), is slightly skewed with a dihedral angle of 7.50 (6)° between the outer benzene rings. The p-tolyl and fluoro-benzene rings are twisted from the attached imidazole ring by 70.40 (7) and 28.33 (7)°, respectively. In the crystal, C-H⋯F hydrogen bonds link the mol-ecules into zigzag chains in [001], and weak C-H⋯π inter-actions further consolidate the crystal packing.

N,N-Dicyclo-hexyl-3,5-dinitro-benzamide.

In the title compound, C(19)H(25)N(3)O(5), the benzene ring is not coplanar with the amide group [dihedral angle = 61.90 (5)°]. The cyclo-hexyl rings are in chair conformations. There is a strong inter-molecular inter-action between the C=O group of the amide group and the nitro group of an adjoining mol-ecule, with a short O⋯N distance of 2.7862 (17) Å. In the crystal, C-H⋯O inter-actions occur along the [100] direction.

1,1,2,2-Tetra-kis[2,4-dichloro-6-(dieth-oxy-meth-yl)phen-oxy-meth-yl]ethene.

In the title compound, C(50)H(60)Cl(8)O(12), the mol-ecules are disordered about an inversion center located at the mid-point of the central C=C bond. These atoms show disorder and were modelled with two different orientations with site occupancies of 0.828 (3) and 0.172 (3). The dihedral angle between the two benzene rings in the asymmetric unit is 52.80 (6)°. Intramolecular C-H⋯O and C-H⋯Cl interactions occur and the crystal packing features inversion dimers linked by pairs of C-H⋯O bonds, generating R(2) (2)(10) loops.

4-(Naphthalene-2-carboxamido)-pyridin-1-ium thio-cyanate-N-(pyridin-4-yl)naphthalene-2-carboxamide (1/1).

The asymmetric unit of the title compound, C(16)H(13)N(2)O(+)·NCS(-)·C(16)H(12)N(2)O, contains two N-(pyridin-4-yl)naphthalene-2-carboxamide mol-ecules, both are partially protonated in the pyridine moiety, i.e. the H atom attached to the pyridine N atom is partially occupied with an occupancy factor of 0.61 (3) and 0.39 (3), respectively. In the crystal, protonated and neutral N-(pyridin-4-yl)naphthalene-2-carboxamide mol-ecules are linked by N-H⋯N hydrogen bonding; the thio-cyanate counter-ion links with both protonated and neutral N-(pyridin-4-yl)naphthalene-2-carboxamide mol-ecules via N-H⋯S and N-H⋯N hydrogen bonding. The dihedral angles between the pyridine ring and naphthalene ring systems are 11.33 (6) and 9.51 (6)°, respectively. π-π stacking is observed in the crystal structure, the shortest centroid-centroid distance being 3.5929 (8) Å. The crystal structure was determined from a nonmerohedral twin {ratio of the twin components = 0.357 (1):0.643 (1) and twin law [-100 0-10 -101]}.

2-Methyl-3-nitro-N-{(E)-[5-(4-nitro-phen-yl)furan-2-yl]methyl-idene}aniline.

In the title Schiff-base type compound, C(18)H(13)N(3)O(5), the central furan ring makes dihedral angles of 12.80 (7) and 51.43 (4)° with the terminal benzene rings. The dihedral angle between the benzene rings is 45.43 (3)°. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into layers parallel to (010). In addition, there are π-π stacking inter-actions within the layer [centroid-centroid distance = 3.584 (1) Å] and between the layers [centroid-centroid distance 3.751 (1) Å].

(E)-{[But-2-ene-1,4-diylbis(-oxy)]bis-(4,1-phenyl-ene)}bis-(phenyl-methanone).

The title mol-ecule, C(30)H(24)O(4), lies about an inversion center located at the mid-point of the central C=C bond. The diphenyl-methanone unit adopts an all-trans conformation. The dihedral angle between the adjacent rings is 53.57 (4)°.

N,N-Dicyclo-hexyl-4-nitro-benzamide.

The title compound, C(19)H(26)N(2)O(3), crystallizes with two independent mol-ecules in the asymmetric unit which differ in the twist of the phenyl rings with respect to the plane of the amide group [the C-C-C-O torsion angles are 121.5 (3) and -119.6 (3)° in the two mol-ecules. Both cyclo-hexane rings adopt chair conformations. In the crystal, weak C-H⋯O inter-actions occur. The crystal studied was a non-merohedral twin with a minor component of 4.8 (1)%.

4-[2-(4-Hy-droxy-phen-yl)eth-yl]-3-propyl-1H-1,2,4-triazol-5(4H)-one.

The asymmetric unit of the title compound, C(13)H(17)N(3)O(2), contains eight crystallographically independent mol-ecules. The planes of the benzene and triazole rings in the eight mol-ecules make dihedral angles of 5.53 (13), 9.33 (13), 19.28 (11), 17.36 (8), 12.84 (12), 8.03 (8), 19.97 (11), and 7.98 (8)°. The eight mol-ecules in the asymmetric unit are linked by inter-molecular O-H⋯O and N-H⋯O hydrogen bonds, forming a three-dimensional network.

2-Chloro-7,8,9,10-tetra-hydro-cyclo-hepta-[b]indol-6(5H)-one.

In the title mol-ecule, C(13)H(12)ClNO, the dihedral angle between the benzene and pyrrole rings is 1.38 (9)°. The cyclo-heptene ring adopts a distorted twist chair and sofa conformation. Inter-molecular N-H⋯O hydrogen bonds form an R(2) (2)(10) loop in the crystal packing. Further, weak C-H⋯O and C-H⋯π (involving the benzene ring) inter-actions are found in the crystal structure.

2-[(E)-(Naphthalen-2-yl-imino)-meth-yl]-4-(trifluoro-meth-oxy)phenol.

In the title compound, C(18)H(12)F(3)NO(2), the planes of the benzene ring and the naphthalene system form a dihedral angle of 47.21 (3)°. The hy-droxy group is involved in an intra-molecular O-H⋯N hydrogen bond. In the crystal, weak C-H⋯O and C-H⋯F inter-actions link the mol-ecules related by translations along the c and a axes, respectively, into sheets.

5-(Thio-phen-2-ylmeth-yl)-1,3,4-thia-diazol-2-amine.

In the title mol-ecule, C(7)H(7)N(3)S(2), the dihedral angle between the thio-phene and thia-diazole rings is 72.99 (5)°; the two rings are oriented so that the S atoms in each ring are on the same side. In the crystal, the three-dimensional network involves strong N-H⋯O hydrogen bonds, as well as C-H⋯π and π-π stacking inter-actions [centroid-centroid distances = 3.654 (1) and 3.495 (1) Å].

2-[(E)-(1,10-Phenanthrolin-5-yl)imino-meth-yl]phenol methanol monosolvate.

In the title multi-donor Schiff base compound, C(19)H(13)N(3)O·CH(3)OH, the dihedral angle between the mean planes of the phenanthroline and phenol rings is 59.3 (1)°. The Schiff base mol-ecule is linked to the solvent mol-ecule by an O-H⋯O hydrogen bond. In the crystal, the components are linked by O-H⋯N hydrogen bonds, weak O-H⋯N inter-actions and π-π stacking inter-actions [centroid-centroid distances = 3.701 (1) and 3.656 (1) Å].

1,2-Diphenyl-1H-benzimidazole.

In the title mol-ecule, C19H14N2, the benzimidazole unit is close to being planar [maximum deviation = 0.0102 (6) Å] and forms dihedral angles of 55.80 (2) and 40.67 (3)° with the adjacent phenyl rings; the dihedral angle between the phenyl rings is 62.37 (3)°. In the crystal, one C-H⋯N hydrogen bond and three weak C-H⋯π inter-actions involving the fused benzene ring and the imidazole ring are observed, leading to a three-dimensional architecture.