Synthesis and some reactions of 1,8-diamino-1-azaazulenium salts

Amination of 8-amino-3-phenyl-1-azaazulene gave 1,8-diamino-3-phenyl-1-azaa zulenium salt (2). Reactions of the salt (2) with triethyl orthoformate and acetic anhydride gave 1-phenyl-2a,3, 5-triazabenz[cd]azulene derivatives ( 3a and 3b). The compound (3a) was also obtained by the reaction of 2 with d iethyl ethoxymethylenemalonate in the presence of potassium carbonate. The reaction of 2 with ethyl pyruvate gave 4-acetyl-1-phenyl-2a, 3,5-triazabenz [cd]azulene (3c). The structure of 3c was deduced by X-Ray structure analys is. Reaction of 2 with acetylenic esters in the presence of potassium carbo nate gave 2a,3-diazabenz[cd]azulene derivatives (10a, b).