The title compound, C19H17N3O3S (I), was prepared by a [3 + 2]cycloaddition azide condensation reaction using sodium azide and l-proline as a Lewis base catalyst. N-Methylation of compound (I) using CH3I gave compound (II), C20H19N3O3S. The benzothiophene ring systems in (I) and (II) are almost planar, with r.m.s deviations from the mean plane = 0.0205 (14) in (I) and 0.016 (2) Å in (II). In (I) and (II), the triazole rings make dihedral angles of 32.68 (5) and 10.43 (8)°, respectively, with the mean planes of the benzothiophene ring systems. The trimethoxy phenyl rings make dihedral angles with the benzothiophene rings of 38.48 (4) in (I) and 60.43 (5)° in (II). In the crystal of (I), the molecules are linked into chains by N—H⋯O hydrogen bonds with R 2 1(5) ring motifs. After the N-methylation of structure (I), no hydrogen-bonding interactions were observed for structure (II). The crystal structure of (II) has a minor component of disorder that corresponds to a 180° flip of the benzothiophene ring system [occupancy ratio 0.9363 (14):0.0637 (14)].
Digital Object Identifier (DOI)
This investigation was supported by NIH/National Cancer Institute grant R01 CA140409.
Penthala, Narsimha Reddy; Madadi, Nikhil Reddy; Bommagani, Shobanbabu; Parkin, Sean; and Crooks, Peter A., "Comparison of Crystal Structures of 4-(benzo[b]thiophen-2-yl)-5-(3,4,5-trimethoxyphenyl)-2H-1,2,3-triazole and 4-(benzo[b]thiophen-2-yl)-2-methyl-5-(3,4,5-trimethoxyphenyl)-2H-1,2,3-triazole" (2014). Chemistry Faculty Publications. 28.
Crystal structure: contains datablock(s) global I, II. DOI: 10.1107/S1600536814023095/hg5414sup1.cif
e-70-00392-Isup2.hkl (218 kB)
Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814023095/hg5414Isup2.hkl
e-70-00392-IIsup3.hkl (224 kB)
Structure factors: contains datablock(s) II. DOI: 10.1107/S1600536814023095/hg5414IIsup3.hkl
e-70-00392-Isup4.cml (7 kB)
Supporting information file. DOI: 10.1107/S1600536814023095/hg5414Isup4.cml
e-70-00392-IIsup5.cml (7 kB)
Supporting information file. DOI: 10.1107/S1600536814023095/hg5414IIsup5.cml