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organic compounds
The title azulene, C17H10BrN, (I), and ester, C26H16O4, (II), are precursors for the preparation of the corresponding 1,8a-dihydroazulenes which are potentially photochromic compounds. In both compounds the azulene moiety is found to be planar. All aromatic bonds in the azulenes lie in the range 1.369 (7)-1.416 (3) Å and the bridging bond between the seven- and five-membered rings is longer, 1.471 (3) and 1.478 (6) Å in (I) and (II), respectively.