Comparison of benzene, nitrobenzene, and dinitrobenzene 2-arylsulfenylpyrroles.
J Org Chem
; 72(19): 7382-5, 2007 Sep 14.
Article
em En
| MEDLINE
| ID: mdl-17705533
ABSTRACT
The effectiveness of the 2,4-dinitrobenzenesulfenyl and 4-nitrobenzenesulfenyl groups as masking and directing groups at the 2-position of pyrrole has been investigated and compared to that of 2-phenylthiopyrrole. The presence of the nitro group(s) enhances stability of the corresponding pyrrole toward acid and does not significantly decrease the ability of the pyrrolic unit to undergo electrophilic aromatic substitution reactions in the form of formylation, nitration, and condensation with aldehydes. The synthetic utility of 2-(2,4-dinitrobenzenesulfenyl)pyrrole was demonstrated through the synthesis of meso-substituted dipyrromethanes. The sulfoxides 2-(2,4-dinitrobenzenesulfinyl)pyrrole and 2-(4-nitrobenzenesulfinyl)pyrrole underwent neither formylation nor nitration, and the increasing presence of nitro groups within the moiety at the 2-position resulted in decreased stability under acidic conditions.
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Base de dados:
MEDLINE
Assunto principal:
Pirróis
/
Sulfamerazina
/
Benzeno
/
Nitrobenzenos
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article