Selective one-pot synthesis of substituted pyrrole-3-phosphonates from alpha-cyanomethyl-beta-ketoesters
TETRAHEDRON, vol.63, no.19, pp.4156-4161, 2007 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 63 Issue: 19
- Publication Date: 2007
- Doi Number: 10.1016/j.tet.2007.02.097
- Journal Name: TETRAHEDRON
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.4156-4161
- Keywords: pyrroles, heteroannulation, GABA analogs, beta-ketophosphonates, pyrrolinones, AMINOBUTYRIC-ACID RECEPTORS, XENOPUS OOCYTES, REGIOSELECTIVE SYNTHESIS, PHOSPHINE OXIDES, (R)-1-ACETYL-5-ISOPROPOXY-3-PYRROLIN-2-ONE, 2-AMINOPYRROLE-4-CARBOXYLATES, PHOSPHONATES, PHARMACOLOGY, PRECURSORS, CLEAVAGE
- Middle East Technical University Affiliated: Yes
Abstract
A one-step synthesis of 5-alkoxypyrrole-3-phosphonates is presented starting from suitable alpha-cyanomethyl-beta-ketophosphonates. The key step in the synthesis involves a one-pot addition and heteroannulation sequence. The zinc perchlorate-catalyzed addition of alcohols to the nitrile carbon of alpha-cyanomethyl- beta-ketophosphonates followed by annulation furnished 5-alkoxypyrrole-3-phosphonates. The addition-annulation process is carried out in the presence of water and 4,5-dihydro-5-oxo-1H-pyrrole-3-phosphonates (pyrrolinones) are obtained in good yields. (C) 2007 Elsevier Ltd. All rights reserved.