Scheme 58. Synthesis of Unsubstituted N- and S-Annulated Perylenes.

Reagents and conditions: (a)⁹⁹ sulfur powder, NMP, 70 °C, then 58.1, 180 °C, 10 h, 50%; (b)¹⁰¹ P(OEt)₃, reflux, 2 h, 85%; (c) m-CPBA, DCM, −78 to 5 °C, 19%; (d)¹⁰⁰ NBS, 1:1 CHCl₃/AcOH, rt, 5 h; (e)¹⁰² α,α′-dibromo-p-xylene, KOH, KI, THF, reflux, 2 days, 50%; (f) N-methyl-4,4′-bipyridinium hexafluorophosphate, MeCN, reflux, 12 h, 50%.