Palladium-Catalyzed Heteroarylamination of Ethyl 2-Chloro-1-azaazulene-3-carboxylate and Annulation of Heteroarylamino-1-azaazurenes

Abstract

The palladium catalyzed heteroarylamination of ethyl 2-chloro-1-azaazulene-3-carboxylate was achieved using a catalyst based on Pd 2 (dba) 3 / Xantphos system.Treatment of ethyl 2-(heteroarylamino)-1-azaazulene-3-carboxylates with a PPA-POCl 3 mixture gave corresponding annulation products.2-(2-Benzothiazolylamino)-1-azaazulene (3h) showed anticancer activity against HeLa S3 cells (IC 50 : 6.5 µM).3][4][5][6] The chemistry of azaazulenes 7 is of interest for their physiological properties 8,9 as well as physical and chemical properties.Therefore, it is expected that heteroarylamino-1-azaazulenes have potential bioactivities.It is known that ethyl 2-chloro-1-azaazulene-3-carboxylate (1) reacted with good nucleophile, such as ----