In a 100 mL round bottom flask, 4 (1.13 g, 2.01 mmol) was dissolved in C6H6 (50 mL). 1M HCl in Et2O (2.01 mL, 2.01 mmol) was added to the stirring solution, and the mixture was allowed to react at RT. After 1h, 1M HCl in Et2O (2.01 mL, 2.01 mmol) was added and the reaction was allowed to stir for an additional hour. The volatile components were removed under reduced pressure and the resulting product recrystallized in heptane to yield the purified product as a white powder. Yield: 0.93 g, 97%. The NMR spectrum obtained agreed with previously reported data.