Abstract Reaction of diethyl 2-chloroazulene-1, 3-dicarboxylate (2) with phenyl magnesium bromide, followed by oxidation with o-chloranil, gave diethyl 2-chloro-4-phenylazulene-1, 3- dicarboxylate (3), diethyl 2-chloro-5-phenylazulene-1, 3-dicarboxylate (4) and diethyl 6- phenylazulene-1, 3-dicarboxylate (5).
