Sodium Hydroxide → (2'S,3R,4'E,6'S)-6-bromo-2'-(3-chlorophenyl)-4'-hydroxyimino-6'-methoxyspiro[1H-indole-3,1'-cyclohexane]-2-one

Participants

Reaction Steps

To the suspension of rac-(1R,2S,6S)-6′-bromo-2-(3-chlorophenyl)-6-methoxyspiro[cyclohexane-1,3′-[3H]indole]-2′,4(1′H)-dione (1.69 g, 3.89 mmol) and NH4OH—HCl (0.27 g, 3.89 mmol) in EtOH (40 mL) was added a queous NaOH solution (1N, 4 mL, 4 mmol). The reaction mixture was heated at reflux for 1 h. TLC analysis indicated the formation of desired product and complete consumption of starting material. The reaction was cooled to room temperature, and water was added. The mixture was extracted with ethyl acetate. The organic layer was separated, dried over MgSO4, and concentrated. The residue was purified by chromatography (EtOAc:hexanes=1:3, 1:2, then 1:1) to give the less polar product rac-E-(1R,2S,6S)-6′-bromo-2-(3-chlorophenyl)-6-methoxy spiro[cyclohexane-1,3′-[3H]indole]-2′,4(1′H)-dione-4-oxime as a white solid (0.8 g, 46%): HRMS (ES+) m/z Calcd for C22H18BrClN2O3+H [(M+H)+]: 449.0262, Found: 449.0260; rac-Z-(1R,2S,6S)-6′-bromo-2-(3-chlorophenyl)-6-methoxy spiro[cyclohexane-1,3′-[3H]indole]-2′,4(1′H)-dione-4-oxime as a white solid (0.8 g, 46%): HRMS (ES+) m/z Calcd for C22H18BrClN2O3+H [(M+H)+]: 449.0262, Found: 449.0261.

Provenance & Evidence