PROCESS FOR THE PREPARATION OF 1-ALKYL-OR 1,4-DIALKYL- 1H-PYRROLE-2-ACETIC ACID ESTERS

PROCESS FOR THE PREPARATION OF 1-ALKYL-OR 1,4-DIALKYL- 1H-PYRROLE-2-ACETIC ACID ESTERS

The invention relates to a new process for the preparation of 1-alkyl- or 1,4-dialkyl-1H-pyrrole- -2-acetic acid, esters of the general formula (I) < IMG > (I) wherein R1 is hydrogen or an alkyl group having from 1 to 4 carbon atoms, R2 and R3 each independently represent an alkyl group having...

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Bibliographische Detailangaben
Hauptverfasser: HARSANYI, KALMAN, KRUZICS, ANNA, MAJOR, PIROSKA, AGAI, EVA, DOMANY, GYORGY, SZOLLOSY, MARTA, MOLNAR, KAROLY
Format: Patent
Sprache:eng ; fre
Schlagworte:
CHEMISTRY
HETEROCYCLIC COMPOUNDS
HUMAN NECESSITIES
HYGIENE
MEDICAL OR VETERINARY SCIENCE
METALLURGY
ORGANIC CHEMISTRY
PREPARATIONS FOR MEDICAL, DENTAL, OR TOILET PURPOSES
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Beschreibung
Zusammenfassung:The invention relates to a new process for the preparation of 1-alkyl- or 1,4-dialkyl-1H-pyrrole- -2-acetic acid, esters of the general formula (I) < IMG > (I) wherein R1 is hydrogen or an alkyl group having from 1 to 4 carbon atoms, R2 and R3 each independently represent an alkyl group having from 1 to 4 carbon atoms, by selective desalkoxycarbonylation of the corresponding 1-alkyl- and 1,4-dialkyl-3-alkoxycarbonyl-1H-pyrrole- -2-acetic acid esters of the general formula (II) < IMG > (II) wherein R1, R2 and R3 have the same meaning as defined above, by heating in the presence of a concentrated mineral acid or an aliphatic or aromatic sulfonic acid. Compounds of the general formula (I) are known pharmaceutically active materials, which can be prepared by this process in a single reaction step selectively, without the formation of by-products.