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Three closely related 4,5,6,7‐tetrahydro‐1 H ‐pyrazolo[4,3‐ c ]pyridines: synthesis, molecular conformations and hydrogen bonding in zero, one and two dimensions
Author(s) -
Sagar Belakavadi K.,
Harsha Kachigere B.,
Yathirajan Hemmige S.,
Rangappa Kanchugarakoppal S.,
Rathore Ravindranath S.,
Glidewell Christopher
Publication year - 2017
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s205322961700273x
Subject(s) - chemistry , trifluoromethyl , isostructural , pyridine , substituent , hydrogen bond , ring (chemistry) , molecule , stereochemistry , crystallography , crystal structure , medicinal chemistry , organic chemistry , alkyl
In each of 1‐(4‐fluorophenyl)‐5‐methylsulfonyl‐3‐[4‐(trifluoromethyl)phenyl]‐4,5,6,7‐tetrahydro‐1 H ‐pyrazolo[4,3‐ c ]pyridine, C 21 H 19 F 4 N 3 O 2 S, (I), 1‐(4‐chlorophenyl)‐5‐methylsulfonyl‐3‐[4‐(trifluoromethyl)phenyl]‐4,5,6,7‐tetrahydro‐1 H ‐pyrazolo[4,3‐ c ]pyridine, C 21 H 19 ClF 3 N 3 O 2 S, (II), and 1‐(3‐methylphenyl)‐5‐methylsulfonyl‐3‐[4‐(trifluoromethyl)phenyl]‐4,5,6,7‐tetrahydro‐1 H ‐pyrazolo[4,3‐ c ]pyridine, C 22 H 22 F 3 N 3 O 2 S, (III), the reduced pyridine ring adopts a half‐chair conformation with the methylsulfonyl substituent occupying an equatorial site. Although compounds (I) and (II) are not isostructural, having the space groups Pbca and P 2 1 2 1 2 1 , respectively, their molecular conformations are very similar, but the conformation of compound (III) differs from those of (I) and (II) in the relative orientation of the N ‐benzyl and methylsulfonyl substituents. In compounds (II) and (III), but not in (I), the trifluoromethyl groups are disordered over two sets of atomic sites. Molecules of (I) are linked into centrosymmetric dimers by C—H…π(arene) hydrogen bonds, molecules of (II) are linked by two C—H…O hydrogen bonds to form ribbons of R 3 3 (18) rings, which are themselves further linked by a C—Cl…π(arene) interaction, and a combination of C—H…O and C—H…π(arene) hydrogen bonds links the molecules of (III) into sheets. Comparisons are made with the structures of some related compounds.