Tetrahedron

Synthesis of 1, 3-diazaazulene derivatives of colchicinoids and isocolchicinoids via ipso-or tele-substitution-condensation with amidines

M Cavazza, F Pietra

Index: Cavazza, Marino; Pietra, Francesco Tetrahedron, 1998 , vol. 54, # 46 p. 14059 - 14064

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Citation Number: 8

Abstract

Condensation of colchicinoids and isocolchicinoids with amidines in dry benzene affords regioselectively 1, 3-diazaazulene derivatives: ipso-substitution-condensation products (eg 7) are best obtained from cycloheptatrienone-ring deactivated substrates (eg 4), whereas isomeric tele-substitution-condensation products (eg 13), are best accessible from cycloheptatrienone-ring activated substrates (eg 10). Hydroxylic solvents inhibit tele- ...