Synthesis of aryl conjugated (1-azaazulenyl)acetylenes and facile synthesis of thiophene fused 1-azaazulenes

3-Ethynyl-1-azaazulene derivatives were obtained by Sonogashira-Hagihara reaction of 3-iodo-2-chloro-1-azaazulenes, and 2-(phenylethynyl)-1-azaazulenes were obtained by the reaction of 2-bromo-1-azaazulenes. Glaser reaction of 2-chloro-3-ethynyl-1-azaazulenes gave 1,4-bis(2-chloro-1-azaazulen-3-yl)-1,3-butadiyne. Treatment of 2-chloro-3-ethynyl-1-azaazulene derivatives with sodium hydrosulfide gave corresponding 1-thia-9-azacyclopent[a]azulene derivatives in good yield.