Synthesis and Some Reactions of 2-Amino-1-azaazulene-3-carbaldehyde

Article abstract of DOI:10.1246/bcsj.65.340

2-Chloro-1-azaazulene-3-carbaldehyde (1a) reacted with pyridine, followed by a reaction with piperidine to give 2-amino-1-azaazulene-3-carbaldehyde (1b) in excellent yield.Compound 1b was also obtained by a Vilsmeier-Haack reaction of 2-amino-1-azaazulene.Acetylation of 1b yielded a 2-acetylamino derivative, whereas methylation gave a 1-methylated compound.Reactions of 1b with hydrazines and alkylamines gave the corresponding hydrazones and Schiff bases, respectively, in excellent yields.The reactions of 1b with active methylene compounds gave 1,10-diazabenzazulen-2(1H)-one derivatives.The reaction of 1b with guanidine gave pyrimidine-fuzed 1-azaazulene.