A Versatile Synthetic Method of 1-Alkylazulenes and Azulene by the iReactions of 3-Methoxycarbonyl-2H-cyclohepta (b) furan-2-one with in situ Generated Enamines.

M Yasunami, S Miyoshi, N Kanegae…

Index: Yasunami, Masafumi; Miyoshi, Shiro; Kanegae, Noriko; Takase, Kahei Bulletin of the Chemical Society of Japan, 1993 , vol. 66, # 3 p. 892 - 899

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Citation Number: 52

Abstract

Methyl 3-alkylazulene-1-carboxylates were synthesized in high yields by the reaction of 3- methoxycarbonyl-2H-cyclohepta [b] furan-2-one with in situ generated morpholine enamines of aldehydes. Treatment of the esters with 100% phosphoric acid gave 1-alkylazulenes in excellent yields. Azulene was also synthesized in a good yield via methyl azulene-1- carboxylate with a modification of this method.

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