tert-butyl 5,7-dichloro-2-(4-methoxybenzyl)-3-oxo-2',3'-dihydro-1'H-spiro[isoindoline-1,4'-pyridine]-1'-carboxylate → 5,7-dichloro-2',3'-dihydro-1'H-spiro[isoindoline-1,4'-pyridin]-3-one

Participants

Reaction Steps

tert-Butyl 5,7-dichloro-2-(4-methoxybenzyl)-3-oxo-2′,3′-dihydro-1′H-spiro[isoindoline-1,4′-pyridine]-1′-carboxylate (3.5 g, 7.2 mmol) in TFA (36 mL) and CF3SO3H (4 mL) was heated to 60° C. for 5 h. The solvent was removed and satd aq NaHCO3 was added till pH=7. Then EtOAc was added, the organic layer was washed with brine, dried and concentrated to give the crude product. It was purified by preparative HPLC to give 5,7-dichloro-2′,3′-dihydro-1′H-spiro[isoindoline-1,4′-pyridin]-3-one (0.2 g, 10%). 1H NMR (CDCl3): 1.66 (m, 3H), 2.81 (m, 1H), 3.15 (m, 1H), 3.76 (m, 1H), 7.57 (m, 1H), 7.75 (m, 1H).

Provenance & Evidence