X-RAY Crystallographic studies of four monosubstituted thienopyridines. comparison of experimental data with calculated or measured values for the parent compounds

摘要

X-ray crystallographic data are reported for thieno[3,2-b]pyridine-2-carbonitrile (1b), thieno[3,2-c]pyridine-4-carbonitrile (2b), 3-acetylaminothieno[2,3-c]pyridine (3b), and ethyl thieno[2,3-b]pyridine-3-carboxylate (4b). All of the thienopyridine ring systems are planar with internal bond angles of 90.7+-0.6deg for C-S-C and 115.9 +-1.9deg for C-N-C. C-S and C-N bond lengths in the rings are 1.73+-0.02 A and 1.34+-0.02 A, respectively. Comparison is made of our measured data with bond angles and lengths calculated from molecular orbital theory for the parent unsubstituted compounds 1a, 2a, and 4a and for reported experimental data for parent 3a. In general, numerical values are remarkably close in the corresponding a and b systems. ~(13)C Nmr spectral data are also reported for 2b-4b.