PALLADIUM-CATALYZED HETEROARYLAMINATION OF ETHYL 2-CHLORO-1-AZAAZULENE-3-CARBOXYLATE AND ANNULATION OF HETEROARYLAMINO-1-AZAAZULENES

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-POCl3 mixture gave corresponding annulation products. 2-(2-Benzothiazolylamino)-1-azaazulene (3h) showed anticancer activity against HeLa S3 cells (IC50: 6.5 mu M).