SYNTHESIS AND STRUCTURE OF 2,6-DI-TERT-BUTYL-1,4-BENZOQUINONE-4N-(8-TOSYLAMINO-1-NAPHTHYL)IMINE

Article abstract of DOI:10.1007/BF01172258

The structure of 2,6-di-tert-butyl-1,4-benzoquinone-4-N-(-tosylamino-1-naphthyl)imine (IId) has been studied as a model for the open form of thermo- and photochromic compounds in the cyclohexadienoneperimidine series (I), in which rearrangement occurs due to C_spiro-N bond cleavage and N <*> N proton transfer upon thermal or photoexcitation.Introduction of a bulky, electron-withdrawing tosyl substituent to the nitrogen atom stabilizes the open quinoneimine form, both in the crystalline state and in solution.The cyclohexadienone fragment is nonplanar and exists in a "boat" configuration.The open quinoneimine structure is retained upon replacement of the tosyl substituent by a less bulky electron-withdrawing acetyl substituent, suggesting that electronic factors are decisive in formation of the open structure.