Hydrochloric Acid → rac-(2'S,3'S,4'S)-6-chloro-2'-(3-chloro-2-fluoro-phenyl)-4'-(3-hydroxy-2,2-dimethyl-propyl)-2-oxo-1,2-dihydro-spiro[indole-3,3'-pyrrolidine]-1'-carboxylic acid ((S)-3,4-dihydroxy-butyl)-amide

Participants

Reaction Steps

To a solution of rac-(2′S,3′S,4′S)-6-chloro-2′-(3-chloro-2-fluoro-phenyl)-4′-(3-hydroxy-2,2-dimethyl-propyl)-1H-spiro[indole-3,3′-pyrrolidin]-2-one prepared in Example 32 (60 mg, 0.14 mmol) in dichloromethane (5 mL) was added saturated aqueous NaHCO3 solution (5 mL). The temperature of the mixture was lowered to 0° C., and a toluene solution (Aldrich, 20%) of phosgene (0.13 mL, 0.25 mmol) was added dropwise via a syringe. The reaction mixture was stirred at room temperature for 30 min, then diluted dichloromethane. The organic layer was separated, the aqueous layer was extracted with dichlormethane twice. The combined organic layers were washed with water, brine, dried over MgSO4, and concentrated. The residue was dissolved into tetrahydrofuran (5 mL), and 2-((S)-2,2-dimethyl-[1,3]-dioxolan-4-yl)-ethylamine prepared in Example 7 (24 mg, 0.16 mmol) and triethylamine (0.038 mL, 0.27 mmol) were added sequentially. The reaction mixture was stirred at room temperature for 1 h. An aqueous HCl solution (1 N, 2 mL) was added. The reaction mixture was stirred at room temperature for 1 h. The solvents were removed and the residue was partitioned between ethyl acetate and saturated aqueous NaHCO3 solution. The organic layer was separated, and the aqueous layer was extracted with ethyl acetate. The organic layers were combined, washed with water, brine, dried over MgSO4, and concentrated. The residue was purified by chromatography (15% MeOH in EtOAc) to give rac-(2′S,3′S,4′S)-6-chloro-2′-(3-chloro-2-fluoro-phenyl)-4′-(3-hydroxy-2,2-dimethyl-propyl)-2-oxo-1,2-dihydro-spiro[indole-3,3′-pyrrolidine]-1′-carboxylic acid ((S)-3,4-dihydroxy-butyl)-amide as a off white solid (Yield 16 mg, 20%).

Provenance & Evidence