Water → racemic (2'R,3R,4'S)-4'-(3-chlorophenyl)-6-cyclopropyl-2'-isopropenylspiro[3H-indole-3,3'-piperidine]-2,6'(1H)-dione

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Reaction Steps

Under nitrogen atmosphere, to a solution of racemic (2′R,3R,4′S)-6-bromo-4′-(3-chlorophenyl)-2′-isopropenyl-2,6′-dioxospiro[indole-3,3′-piperidine]-1-carboxyl acid tert-butyl ester (0.050 g) prepared in Example 172b in toluene (5 mL) was added water (0.1 mL), cyclopropyl boronic acid (0.020 g, 0.23 mmol), K3PO4 (0.098 g, 0.46 mmol), and Pd(PPh3)4 (0.018 g, 0.016 mmol). The mixture was irradiated at 130° C. by microwave for 0.5 h. Then cooled to room temperature and filtered through a short pad of silica gel, the silica gel was washed with ethyl acetate. The filtrate was concentrated. To the residue was added trifluoroacetic acid (5 mL). The solution was stirred at room temperature for 0.5 h, then partitioned between ethyl acetate and water. The organic layer was separated, and the aqueous layer was extracted with ethyl acetate. The combined organic layer was washed with NaHCO3 aqueous solution, dried over MgSO4 and concentrated. The residue was purified with Prep.LC to give title compound as a white solid (Yield: 8 mg).

Provenance & Evidence