The synthesis of methyl 6-(trifluoromethylsulfonyloxy)-1-naphthoate is as follows:
Diisopropylethyiamine (2.35 mL, 13,5 mmol) and irifluoromethanesuifonic anhydride (0,95 mL, 5.6 mmol) were added sequentially to a solution of methyl 6-hydroxy- l- naphthoate ( 10 mg, 4.5 mmol) in CH2C12 (60 mL) at - 78 °C. After 1 h at - 78 °C, the reaction mixture was poured into saturated aqueous NH4C1 (30 mL). The resulting mixture was extracted with CH2CI2 (3x50 mL). The combined organic phase was washed with brine (50 mL) then dried ( a2S0 ), filtered and concentrated in vacuo. The resulting residue was purified on 80 g silica gel (100% hexanes - 100% EtOAc, gradient) to afford 1 ,45 g (96%) of methyl 6-(trifluoromethylsulfonyloxy)-1-naphthoate.
