Chlorotrimethylsilane → Benzyl 3-(3-acetyl-5-chloro-2-methoxy-6-methylphenyl)azetidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Zinc (1.15 g, 17.6 mmol) was suspended with 1,2-dibromoethane (0.101 mL, 1.17 mmol) in DMF (21 mL). The mixture was heated at 70° C. for 10 min and then cooled to room temperature. Chlorotrimethylsilane (0.149 mL, 1.17 mmol) was added dropwise and stirring was continued for 1 hour. A solution of benzyl 3-iodoazetidine-1-carboxylate (4.6 g, 15 mmol, from Pharmablock) in DMF (20 mL) was then added and the mixture was heated at 40° C. for 1 h before a mixture of 1-(5-chloro-3-iodo-2-methoxy-4-methylphenyl)ethanone (5.0 g, 15 mmol, from Example 60, Step 2), tris(dibenzylideneacetone)dipalladium(0) (0.27 g, 0.29 mmol) and tri-(2-furyl)phosphine (0.14 g, 0.59 mmol) in DMF (40 mL) was added. The reaction mixture was warmed to 70° C. and stirred overnight. The mixture was then cooled to room temperature and partitioned between ether and sat. NH4Cl solution. The organic layer was washed with water, dried over MgSO4, concentrated and purified on silica gel (eluting with 0 to 20% EtOAc in hexane) to give the desired product (2.5 g, 44%). LCMS calculated for C21H23ClNO4 (M+H)+: m/z=338.1. found: 388.1.

Provenance & Evidence