In a 2-neck round bottom flask, 150 ml of a mixture o chloroform and acetic acid (1:1, v/v) were added under inert atmosphere along with a magnetic stirrer. N-bromosuccinimide (180 mmol, 1.1 eq, 32.7 g) was then added, and the solution was cooled down to 0 °C for 30 mins by using an ice bath. Compound 1 (163 mmol, 1 eq, 27.56 g) was added dropwise, while the mixture was at 0 °C and it was allowed to gradually warm up to room temperature. The reaction mixture was stirred for 12 hours. The flask and the ice bath were covered in aluminum foil to avoid decomposition of the N-bromosuccinimide. After 12 h, the mixture was diluted by adding 150 ml of dichloromethane, the resulting organic phase was washed with a saturated solution of NaHCO3 (3x150 ml) and was dried over anhydrous MgSO4 and filtered. The organic phase was then evaporated. No purification was performed and product 2 was obtained as a dark yellow oil. Yield: 38.94 g, 95%.