Nitration of triptycene in acetic anhydride

Synthesis and Characterization of Poly(2,6-triptycene)

“…23 The predominant β-nitration was previously attributed to resonance effects, steric factors, and/or strained-ring effects and has been extensively discussed by Klanderman and Perkins. 23d,24 It is worth noting a small amount of 2,7dinitrotriptycene and trinitrotriptycene could also be isolated. 23 The latter was previously reported to be the major product of a similar reaction with higher reaction temperature and prolonged reaction time.…”

“…2,6-Dinitrotriptycene (1). 9,[23][24][25] To a solution of triptycene (21 g, 81 mmol) in acetic anhydride (400 mL) cooled by an ice-water bath was added dropwise a concentrated solution of nitric acid (68-70%, 31 mL). After addition, the ice-water bath was removed, and the mixture was allowed to warm to room temperature and stirred at room temperature for an additional 3.5 h. The reaction mixture was poured into water (1.2 L), and the resulting mixture was stirred vigorously overnight.…”

Homoconjugation and Intramolecular Charge Transfer in Extended Aromatic Triptycenes with Different π-Planes

“…45 Starting from a hexahydroxy triptycene, the selective oxidation to mono-, bis-and trisortho-quinones was possible in high yields of up to 79%. This observation, as well as the fact that triptycene is preferably mononitrated (up to 58%), 40,46,47 monoformylated (up to 60%), 48 or monoacetylated (up to 84%), 48 gives an experimental hint that, by homoconjugation, the attached electron-withdrawing groups of one phenylene ring are diminishing the electron density of the two others by homoconjugation since otherwise only statistical mixtures of all possible (mono-to threefold reacted) products would be obtained. It is worth mentioning that homoconjugation effects are not only of fundamental interest.…”