Potassium Hydroxide → 6-chloro-4'-[5-chloro-2-(1-hydroxycarbonyl-1-methyl-ethoxy)-phenyl]-2'-(5-fluoro-2-methyl-phenyl) spiro[3H-indole-3,3'-piperidine]-2,6'(1H)-dione

Participants

Reaction Steps

Racemic (2′S, 3S, 4′R)-6-chloro-4′-[5-chloro-2-(1-ethoxycarbonyl-1-methyl-ethoxy)-phenyl]-2′-(5-fluoro-2-methyl phenyl) spiro[3H-indole-3,3′-piperidine]-2,6′(1H)-dione (2.7 g, 4.5 mmol) prepared in Example 5 was dissolved in THF (20 mL). Then aqueous solution (10 mL) of KOH (0.5 g) was added. The mixture was refluxed for 1 h. After cooled to room temperature, the solution was concentrated and then the residue was acidified to “pH” 2-3 by addition of concentrated aqueous HCl solution. The white solid was collected by filtration to give title compound (1.6 g).

Provenance & Evidence