Premium
Reactions of electron‐rich heterocycles with orthocarboxylic acid derivatives. 11 . Reactions of carbazole and 4‐methoxycarbazole with triethyl orthoformate: Regiospecific functionalization of the carbazole nucleus
Author(s) -
Witzel H.,
Pindur U.
Publication year - 1988
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.5570250339
Subject(s) - triethyl orthoformate , chemistry , carbazole , electrophile , amide , electrophilic substitution , surface modification , medicinal chemistry , organic chemistry , catalysis
Abstract Carbazole ( 1a ) and 4‐methoxycarbazole ( 1b ) can be regioselectively functionalized by reaction with triethyl orthoformate. Whereas the reaction of 1a with the ortho ester furnishes the amide acetal 2 , the new carbazole derivatives 4–10 are formed, depending on the reaction conditions, in the electrophilic substitution of 1b . The products of this reaction sequence provide a contribution to studies on the mechanism of the transformation of 1b to tris‐carbazolylmethane 5 . Compound 5 represents a new, three‐bladed propeller in the triheteroarylmethane series.