Synthesis and some reactions of n-amino-2-methoxy-1-azaazulenium salt: leading to 3,3a-diazacyclopent[a]azulene and 2a,3-diazabenz[cd]azulene systems

Creators Abe Noritaka

Creators Odagiri Kunihiko

Creators Kakehi Akikazu

N-Amino-2-methoxy-1-azaazulenium salt 2 has been synthesized from 2-methoxy-1-azaazulene with O-mesitylenesulfonylhydroxylamine and its structure has been characterized by X-ray crystal analysis. The salt 2 reacts with ethyl cyanoacetate in the presence of potassium carbonate in acetonitrile to give ethyl (1-amino-1,2-dihydro-1-azaazulen-2-ylidene)cyanoacetate 4, which undergoes cyclization with potassium carbonate in ethanol to give ethyl 2-amino-3,3a-diazacyclopent[a]azulene-1-carboxylate. Reaction of 2 with diethyl ethoxymethylenemalonate in the presence of potassium carbonate in acetonitrile gives ethyl 2-methoxy-2a,3-diazabenz[cd]azulene-5-carboxylate and ethyl 3,3a-diazacyclopent[a]azulene-1-carboxylate as cyclization products. Cycloaddition of the salt 2 with an acetylenic ester proceeds regioselectively and gives 3,3a-diazacyclopent[a]azulene derivatives and 2a,3-diazabenz[cd]azulene derivatives.

[ISSN]0300-922X

[NCID]AA00695134

info:doi/10.1039/a701793f

[isVersionOf] [URI]http://www.rsc.org/Publishing/Journals/P1/Index.asp