Lawesson's reagent → racemic (2'S,3R)-6-chloro-2'-(3-chlorophenyl)-4'-isopropyl-6'-thioxospiro[3H-indole-3,3'-piperidine]-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

The mixture of racemic (2′S,3R)-6-chloro-2′-(3-chlorophenyl)-4′,4′-isopropylspiro[3H-indole-3,3′-piperidine]-2,6′(1H)-dione (60 mg, 0.15 mmol) prepared in example 3b and 2,4-bis-(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane 2,4-disulfide (100 mg, 0.25 mmol) (Aldrich) in toluene (20 mL) was heated at 120° C. for 0.5 h. The mixture was cooled to room temperature and then concentrated. The residue was purified by chromatography (EtOAc:hexanes=1:1) to give racemic (2′S,3R)-6-chloro-2′-(3-chlorophenyl)-4′-isopropyl-6′-thioxospiro[3H-indole-3,3′-piperidine]-2(1H)-one as a white solid (Yield 60 mg, 92%).

Provenance & Evidence