To a solution of 7 (454 mg, 1.2 mmol) in pyridine 10 mL was added 5-hydroxy-2-methyl-benzoic acid methyl ester (412 mg, 2.4 mmol). The reaction mixture was heated to reflux for 5 days. Once the reaction was determined to be complete by TLC, the reaction mixture was diluted with EtOAc (100 mL) and washed two times with 100 mL portions of saturated aqueous ammonium chloride. The combined organic layers were dried over MgSO4 filtered and concentrated in vacuo to give a crude brown oil. The resulting oil was purified on ISCO (EtOAc/Hexanes=2/3) to give title compound 8 as a yellow oil.
