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Benzannelated analogs of phenanthro[1,2‐ b ]‐ and [2,1‐ b ]thiophene: Synthesis and structural characterization by two‐dimensional NMR and X‐ray techniques
Author(s) -
Stuart John G.,
Quast Michael J.,
Martin Gary E.,
Lynch Vincent M.,
Simonsen Stanley H.,
Lee Milton L.,
Castle Raymond N.,
Dallas Jerry L.,
John Boban K.,
Johnson LeRoy F.
Publication year - 1986
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570230451
Subject(s) - thiophene , chemistry , intramolecular force , heteronuclear molecule , planarity testing , molecule , crystallography , intermolecular force , chemical shift , stereochemistry , carbon 13 nmr , single crystal , nuclear magnetic resonance spectroscopy , organic chemistry
Syntheses of benzo[3,4]phenanthro[1,2‐ b ]thiophene, benzo[3,4]phenanthro[2,1‐ b ]thiophene and their 1‐methyl analogs are reported as potential constituents of solvent refined coal liquids and for mutagenicity testing. The attempted synthesis of the 13‐methyl analogs which gave the 11‐methyl isomers is also described. Total assignments of the 1 H‐ and 13 C‐nmr spectra based on long range optimized heteronuclear protoncarbon two‐dimensional chemical shift correlation are reported. Carbon assignments obtained for benzo[3,4]‐phenanthro[1,2‐ b ]thiophene using this approach were confirmed with a 125 MHz 13 C– 13 C INADEQUATE spectrum. X‐Ray crystal structures were determined for benzo[3,4]phenanthro[1,2‐ b ]thiophene and 1‐methyl‐benzo[3,4]phenanthro[2,1‐ b ]thiophene. Both molecules were helically distorted from planarity. Close intramolecular contacts between the bay region H1–H13 and ClMe‐H13 of 2.03 and 2.28 Å, respectively, were responsible for the distortions. There were no close intermolecular contacts of <3.5Å. both molecules refined to an R value of <0.05.