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

Temperature

-78 °C

A solution of lithiothiophene was prepared by the addition of 0.10 g (0.095 mL, 1.2 mmol) of thiophene to a cold solution (-78° C.) of 0.61 g (0.90 mL, 1.4 mmol, 1.6M in hexanes) of n-butyl lithium in 2.0 mL of tetrahydrofuran. The solution was stirred at -78° C. for 35 min and then a solution of 0.158 g (1.2 mmol) of zinc chloride in 2.0 mL of tetrahydrofuran was added. The resulting solution was stirred at -78° C. to room temperature for 1 h and then the organozinc was added via cannula to a mixture of 0.212 g (0.44 mmol) of ethyl(E)-4-[2-(5,5-dimethyl-8-(trifluoromethylsulfonyl)oxy-5,6-dihydronaphthalen-2-yl)ethenyl]benzoate (Compound A9) and 18 mg (0.016 mmol) of tetrakis(triphenylphosphine)palladium(0) in 2.0 mL of tetrahydrofuran. The resulting mixture was stirred at room temperature for 10 min and then heated at 50° C. for 1 h. The reaction was quenched by the addition of sat. aqueous NH4Cl. The mixture was extracted with EtOAc (2×), and washed with brine. The organic phase was dried over Na2SO4 and then concentrated in vacuo. The crude material product was purified by flash chromatography (silica, 15% ethyl acetate in hexanes) to afford the title compound as a solid.

1. stirringThe resulting solution was stirred at -78° C. to room temperature for 1 h
2. stirringThe resulting mixture was stirred at room temperature for 10 min
3. temperatureheated at 50° C. for 1 h
4. customThe reaction was quenched by the addition of sat. aqueous NH4Cl
5. extractionThe mixture was extracted with EtOAc (2×)
6. washwashed with brine
7. dry with materialThe organic phase was dried over Na2SO4
8. concentrationconcentrated in vacuo
9. customThe crude material product was purified by flash chromatography (silica, 15% ethyl acetate in hexanes)

ORD record

ord-833ae973b3214608bac2a8fbd227ff25

Source dataset

uspto-grants-1998_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05723666