Perchloric Acid → Methyl 2-{3-bromothieno[2,3-b]pyridin-2-yl}-2-(tert-butoxy)acetate
Reaction equation
Cl(O)(=O)(=O)=O.[Br:6][C:7]1[C:15]2[C:10](=[N:11][CH:12]=[CH:13][CH:14]=2)[S:9][C:8]=1[CH:16]([OH:21])[C:17]([O:19][CH3:20])=[O:18]>C(OC(C)(C)C)(=O)C>[Br:6][C:7]1[C:15]2[C:10](=[N:11][CH:12]=[CH:13][CH:14]=2)[S:9][C:8]=1[CH:16]([O:21][C:15]([CH3:7])([CH3:10])[CH3:14])[C:17]([O:19][CH3:20])=[O:18]Participants
4
Procedure
Under a nitrogen atmosphere, perchloric acid (70%, 750 μL) was added at −10° C. to a solution of methyl 2-{3-bromothieno[2,3-b]pyridin-2-yl}-2-hydroxyacetate (14f) (180 mg, 0.6 mmol) in tertbutyl acetate (5 mL). After 1 hour, the reaction was quenched with a saturated aqueous solution of sodium bicarbonate and extracted with dichloromethane (2×10 mL). The organic layer was washed with brine (10 mL), dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was purified by flash chromatography on silica gel (dichloromethane/ethyl acetate 90/10) to afford the desired product (14g) as a white solid (55 mg, 0.15 mmol, 26%).