Premium
A New Synthesis of Push‐Pull Pyrroles, Their Oxidation to Stable 3 H ‐Pyrroles and an Unexpected Anellation Reaction
Author(s) -
Buehrdel Gunther,
Beckert Rainer,
Herzigova Petra,
Petrlikova Eva,
Schuch Dirk,
Birckner Eckhard,
Goerls Helmar
Publication year - 2009
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200900295
Subject(s) - chemistry , intramolecular force , benzothiazole , ring (chemistry) , medicinal chemistry , oxidative phosphorylation , combinatorial chemistry , stereochemistry , organic chemistry , biochemistry
A new synthesis of push‐pull pyrroles of type 5 was developed starting from bis(imidoyl chlorides) 1 and various iminodiacetic acid derivatives 3 . The use of appropriate N ‐trifluoroacetyl residues as protecting/activating group proved to be the method of choice for the straightforward preparation of the 3,4‐diarylamino‐1 H ‐pyrroles 5 . When benzothiazole substructures are present in 2,5‐position of heterocycles 5 , a two‐electron oxidation leads to 3 H ‐pyrroles of type 6 in excellent yields. However, in the case of cyano or ester groups, a further oxidative process immediately led to the new 3 H ‐pyrrolo[3,4‐ b ]quinoxalines 7 via intramolecular ring anellation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)