Zur Constitutionsfrage des Chinolins

Abstract

In analoger Weise habe ich durch Einwirkung von Anilin, Paratoluidin und jj-Naphtylamin die a m S t i c k s t o f f s u b s t i t u i r t e n P y r r o l d e r i v a t e gewonnen. I n iihnlicher Weise werden voraussichtlich alle p r i n i a r e n A m i nb a s e n auf den Diacetbernsteinsaureester reagiren. I n ihrem gesammten Verhalten sind alle diese Produkte dem fruher beschriebenen Dimethylpyrroldicarbonsiiureester ausserordentlich ahnlich. Da die msfuhrliche 'Untersuchung dieser KGrper wohl noch langere Zeit in Anspruch nehmen wjrd, so miichte ich mir durch diese kurze Notiz die ungestiirte Rearbeitung dieses Capitels sichern. 617. Ludwig K n o w und Otto Antrick: Zur Constitutionsfrage des Chinolins.

Hexaalkylguanidinium salts as ionic liquids – applications in titanium and aluminium alcoholate assisted synthesis

“…61 Up to day a great number of pyrrole syntheses exists, of which the Paal-Knorr condensation is the most simple, straightforward reaction, which consists in an acid-catalysed cyclisation of a 1,4-dicarbonyl compound and ammonia or a primary amine. Although this reaction was rst reported concurrently by C. Paal 62 and L. Knorr 63 already in 1884, it still awakes the interest of researchers, who continue to develop new catalysts and solvents to render the reaction "green". Noteworthy, a Paal-Knorr condensation is one of the steps in the synthesis of atorvastatin, a drug for lowering cholesterol levels.…”

Ribose conversion with amino acids into pyrraline platform chemicals – expeditious synthesis of diverse pyrrole-fused alkaloid compounds

“…1). [10][11][12] The Hantzsch method by the reaction of a-haloketone and b-ketoester with a primary amine is useful for the preparation of 3-carboxylated pyrroles. 13,14 In 1948, Clauson-Kaas reported furan conversion into 2,5-dimethoxytetrahydrofuran for the efficient preparation of pyrroles.…”

Cascade Synthesis of Pyrroles from Nitroarenes with Benign Reductants Using a Heterogeneous Cobalt Catalyst

“…Hence, a variety of methods for their synthesis exists, including traditional, but still popular, Hantzsch and Paal–Knorr synthesis. Since its discovery in 1884, the latter reaction (1,4‐diketones and primary amines) remains a reliable transformation that continues to be used, for example, in the total synthesis of natural products. As a prominent example, the pyrrole ring of the drug Lipitor is produced on an industrial scale using Paal–Knorr synthesis…”