Synthesis of α-carbolines starting from 2,3-dichloropyridines and substituted anilines
9H-α-Carbolines have been prepared via consecutive intermolecular Buchwald-Hartwig reaction and Pd-catalyzed intramolecular direct arylation from commercially available 2,3-dichloropyridines and substituted anilines. The combination of a high reaction temperature (180°C) and the use of DBU were found to be crucial for the intramolecular direct arylation reactions of the 3-chloro-N-phenylpyridin-2-amines as no reaction was observed at 120°C and 180°C using different inorganic and other organic bases. On the other hand, nitrogen-methylated pyridine analogues of these substrates {N-[3-chloro-1- methylpyridin-2(1H)-ylidene]anilines} do undergo ring closure at 120°C, with K3PO4 as base, affording the respective 1-methyl-1H-α-carbolines in good yields.
Hostyn, Steven,Van Baelen, Gitte,Lemiere, Guy L. F.,Maes, Bert U. W.
supporting information; scheme or table
p. 2653 - 2660
(2009/08/14)
More Articles about upstream products of 1163681-46-6