title: Structural characterization of [1,4]diazepino[6,5-b]indoles by powder diffraction.
abstract: As part of a systematic structural study of potentially pharmacologically active [1,4]diazepino[6,5-b]indoles, the crystal structures of nine compounds have been determined from laboratory powder diffraction data. The investigated compounds are: 2-oxo-1-(4-nitrophenyl)-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(17)H(12)N(4)O(4) (1a); 2-oxo-1-phenyl-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(17)H(13)N(3)O(2) (1b); 2-oxo-1-(4-ethoxyphenyl)-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(19)H(17)N(3)O(3) (1c); 2-oxo-1-(4-chlorophenyl)-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(17)H(12)N(3)O(2)Cl (1d); 2-oxo-1-(4-cyanophenyl)-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(18)H(12)N(4)O(2) (1e); 6-methyl-2-oxo-1-phenyl-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(18)H(15)N(3)O(2) (1f); 2-formyl-3-[N'-(omega-chloracetyl)-N'-(4-nitrophenyl)]aminoindole, C(17)H(12)N(3)O(4)Cl (2a); 2-formyl-3-[N'-(omega-chloracetyl)-N'-(4-nitrophenyl)]aminoindole solvate with toluene (2:1), C(17)H(12)N(3)O(4)Cl.0.5C(7)H(8) (2as); 2-formyl-3-[N'-(omega-chloracetyl)-N'-(4-cyanophenyl)]aminoindole, C(18)H(12)N(3)O(2)Cl (2e). Compounds (1a)-(1f) crystallize in non-centrosymmetric triclinic, monoclinic and orthorhombic space groups. The three-dimensional structures of (1a)-(1e) demonstrate identical intermolecular NH(indole)...O<--N hydrogen bonds, which form linear chains of connected molecules. A comparison of the crystal structures (2a), (2e) and (2as) shows that the solvent used in the re-crystallization of (2a) and (2e), which are intermediates in the synthesis of (1a) and (1e), affects the intermolecular hydrogen-bond formation and, as a result, leads to essentially different yields of the goal products.
authors.affiliation: Department of Medicinal Chemistry, State Scientific Center of Antibiotics, Nagatinskaya str. 3a, 113105 Moscow, Russia.
authors.forename: Svetlana Yu
authors.initials: SY
authors.lastname: Ryabova
authors.forename: Nina A
authors.initials: NA
authors.lastname: Rastorgueva
authors.forename: Eduard J
authors.initials: EJ
authors.lastname: Sonneveld
authors.forename: Rene
authors.initials: R
authors.lastname: Peschar
authors.forename: Henk
authors.initials: H
authors.lastname: Schenk
authors.forename: Viktor A
authors.initials: VA
authors.lastname: Tafeenko
authors.forename: Leonid A
authors.initials: LA
authors.lastname: Aslanov
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Chernyshev