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Chemistry of condensed thiophenes. IV . Acetylation of phenanthro[4,5‐ bcd ]thiophene
Author(s) -
Klemm L. H.,
Lam Lee,
Severns Bryon,
Sur Sandip K.
Publication year - 1990
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.5570270722
Subject(s) - chemistry , nitration , nitrobenzene , yield (engineering) , thiophene , acetylation , diacetyl , sulfur , chloride , organic chemistry , medicinal chemistry , catalysis , biochemistry , materials science , metallurgy , gene
Treatment of phenanthro[4,5‐ bcd ]thiophene ( 2 ) with acetyl chloride and aluminum chloride in nitrobenzene gives acetylation of positions ortho and para to the heteroatomic sulfur atom. In separate experiments, mixtures of 1‐ and 3‐acetyl (50% yield, ratio 1.9:1) or of 1,5‐, 1,7‐, and 3,5‐diacetyl (79% yield, ratio 3:1:1) derivatives were obtained. Isolated as isomerically pure products were the 1‐acetyl and the 1,5‐diacetyl compounds, as well as the oximes of the 1‐ and 3‐acetyl derivatives. Comparison of these results is made with those reported for nitration of 2 , which also occurs ortho and para to the sulfur atom, and with nitration and acetylation of pyrene (the benzolog of 2 ) which substitutes in the corresponding positions.