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Bromothiophene reactions. II. A novel rearrangement in the zinc and acetic acid reduction
Author(s) -
AlvarezInsúa A. S.,
Conde S.,
Corral C.
Publication year - 1982
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.5570190402
Subject(s) - chemistry , acetic acid , protonation , zinc , ring (chemistry) , side chain , medicinal chemistry , bromine , oxygen atom , carbon atom , stereochemistry , organic chemistry , ion , molecule , polymer
The elimination of the α‐bromine atoms of the bromothienylethanolamine derivatives 2a,b,c,d with zinc and acetic acid unexpectedly involved a migration of the ethanolamine side chain from the 3 to the 2 position in the thiophene ring. Experiments carried out with simpler analogous compounds 3, 4 and 6 seem to indicate that this rearrangement takes place only in those cases in which the carbon atom of the side chain next to the ring supports an oxygen atom capable of being protonated in the reaction medium. A tentative mechanism is proposed to explain the experimental results.