102435-13-2Relevant academic research and scientific papers
Novel 2,6-Disubstituted Azulenes
Balschukat, Dietmar,Dehmlow, Eckehard V.
, p. 2272 - 2288 (2007/10/02)
Methods are described to introduce varying residues into 2- and 6-positions of azulene, starting from diethyl 6-bromo-2-methoxy-1,3-azulenedicarboxylate (1). 2-Substitution is achieved by Grignard reaction or exchange of the alkoxy group and by aldol condensation of 2-methyl compounds whereas 6-substitution is conducted by nucleophilic displacement and by homo- and hetero-aromatic coupling.Consecutive dealkoxycarbonylation yields azulenes 20 with free 1,3-positions.Biazulenes 9a - c and 20l, 20m, styryl- and bis(styryl)azulenes 15 - 18 and 20i - k, and finally the azulenedialdehyde 19 are novel compounds which were difficult to prepare or were inaccessible so far.
