Compound 2 (1 eq.), K 2 CO 3 (3 eq.) and the halogenated linker (1.5 eq.) was dissolved in DMF (~ 50 mL per mmol) and heated at 70 °C overnight. Complete conversion of the starting material was observed by LC-MS (acidic method). The reaction mixture was taken up with water and extracted with DCM (x3). Organic layers were collected, dried over MgSO 4 , evaporated under reduced pressure and purified by HPLC using a gradient from 5% to 95% acetonitrile with 0.01% v/v aqueous solution of formic acid over 10 min to yield the desired compound.