Hydrochloric Acid → HCID 58137281, compound

Participants

Reaction Steps

Tert-butyl 7-chloro-2-(4-methoxybenzyl)-3-oxo-2′,3′-dihydro-1′H-spiro[isoindoline-1,4′-pyridine]-1′-carboxylate (1.69 g, 3.71 mmol, 1.0 equiv) and PtO2 (100 mg, 0.440 mmol, 12 mol %) were added to a solution of 1:1 4.0 M HCl:MeCN (200 mL). The mixture was transferred to a Parr hydrogenation vessel and hydrogenated at 55 psi for 3 d. After this time the vessel was vented and the pale yellow solution filtered through a bed of Celite. The mixture was evaporated and the residue was dissolved in 1:1 MeCN:10% aq K2CO3 (200 mL); Boc2O (1.21 g, 5.56 mmol, 1.5 equiv) was added and the mixture was stirred for 17 h. After this time the solution was evaporated and the residue was diluted with EtOAc. The organic layer was washed with 1.0 M aq HCl and brine, dried over Na2SO4, and evaporated. The reduced product was purified by flash chromatography on silica gel, eluting with 20-80% EtOAc in hexanes. Tert-butyl 7-chloro-2-(4-methoxybenzyl)-3-oxospiro[isoindoline-1,4′-piperidine]-1′-carboxylate was isolated as a pale yellow foam (0.702 g, 1.54 mmol, 42%).

Provenance & Evidence