Synlett 2009(14): 2245-2248  
DOI: 10.1055/s-0029-1217799
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Iron-Catalyzed Inexpensive and Practical Synthesis of N-Substituted Pyrroles in Water

Najmedin Azizi*a, Alireza Khajeh-Amiria, Hossein Ghafurib, Mohammad Bolourtchiana, Mohammad Reza Saidib
a Chemistry & Chemical Engineering Research Center of Iran, P.O. Box 14335-186, Tehran, Iran
Fax: +98(21)44580762; e-Mail: azizi@ccerci.ac.ir;
b Department of Chemistry, Sharif University of Technology, P. O. Box 11465-9516, Tehran 11365, Iran
Further Information

Publication History

Received 27 April 2009
Publication Date:
06 August 2009 (online)

Abstract

An operationally simple, practical, and economical protocol for iron(III) chloride catalyzed Paal-Knorr pyrrole synthesis in water in good to excellent yields has been developed. Several N-substituted pyrroles are readily prepared from the reaction of 2,5-dimethoxytetrahydrofuran and aryl/alkyl, sulfonyl and acyl amines under very mild reaction conditions

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General Procedure for the Synthesis of Pyrroles in Water To a mixture of the amine (5 mmol) and 2,5 dimethoxy-tetrahydrofuran (6 mmol) in H2O (4 mL) at 60 ˚C FeCl3˙7H2O (2 mol%) was added. The mixture was stirred at this temperature for 1-4 h and was diluted with EtOAc and filtered. The organic solution was evaporated under vacuum affording the pyrrole derivative with good analytical purity. In the few cases, the crude product was purified by flash chromatography.