Guaiazulene formed blue needle crystals on reaction with maleic anhydride or acrylic acid in a boiling water bath. The products obtained in this experiment were confirmed as 3-(7-isopropyl-1, 4-dimethyl) azulenyl compounds from visible, infrared, nuclear magnetic resonance, and mass spectra, and maleic anhydride adduct was found to be dissociated at a high temperature from gas chromatography and mass spectra.
