On amination and diazotization of azulene and its derivatives

A practical procedure for synthesis of 6-aminoazulene (3) via Vicarious Nuc leophilic Substitution of Hydrogen (VNS) amination of azulene with 4-amino- 1,2,4-triazole is reported. Amination with use of N,N,N-trimethylhydraziniu m iodide (TMHI) of more electrophilic azulene derivatives, substituted at p osition 1- with CN or COPh group, afforded a mixture of 4-, 6-, and 8-amino azulenes, Attempts to convert 6-aminoazulene (3) into diazonium salt failed , only formation of small quantities of the "auto-coupling" product, 1-(azu len-6-ylazo)-azulen-6-yl-amine, was observed.