Thiazole → Ethyl (E)-4-[2-(5,5-dimethyl-8-(thiazol-2-yl)-5,6-dihydronaphthalen-2-yl)ethenyl]-benzoate

Participants

Reaction Steps

To a cold (−78° C.) solution of thiazole (0.38 g (0.10 mL, 1.4 mmol) in THF (2.0 mL) was added n-butyl lithium (1.6 M solution in hexanes, 0.5 mL, 0.8 mmol) and stirred for 30 min. To this solution was added 0.176 g (1.3 mmol) of zinc chloride in 3.0 mL of tetrahydrofuran and stirred for 45 min. The resulting turbid solution was transferred, via cannula, to a flask containing a mixture of 0.17 g (0.35 mmol) of ethyl (E)-4-[2-(5,5-dimethyl-8-(trifluoromethylsulfonyl)oxy-5,6-dihydronaphthalen-2-yl)ethenyl]benzoate (Compound A9) and 15 mg (0.01 mmol) of tetrakis(triphenylphosphine)palladium(0) in 3.0 mL of tetrahydrofuran. The reaction mixture was stirred for 1 h at ambient temperature and 1.5 h at 55° C. The reaction mixture was treated with aqueous NH4Cl, and extracted with EtOAc (2×). The combined organic layer was washed with brine and dried (MgSO4). The solvent was removed under reduced pressure and the crude product was purified by flash chromatography (silica, 20% ethyl acetate in hexane) to afford the title compound as a white solid.

Provenance & Evidence