Reaction #1481

Reaction equation

ethyl 4-[(5,6-dihydro-5,5-dimethyl-8-trifluoromethylsulfonyloxy-naphthalen-2-yl)azo]benzoate

thiophene

t-BuLi

→

title compound

Ethyl 4-[(5,5-dimethyl-8-(2-thienyl)-5,6-dihydronaphthalen-2-yl)azo]benzoate

Solvents

THF

THF

NH4Cl

THF

Conditions

Workup

1. 1
   workup.STIRRINGstirred for 1 h
2. 2
   TemperatureThe resulting mixture was heated at 50° C. for 2.5 h
3. 3
   Extractionextracted with ethyl acetate
4. 4
   DryingThe combined organic layer was dried over Na2SO4
5. 5
   Concentrationconcentrated to an oil
6. 6
   OtherThe crude product was purified by flash chromatography (silica, ethyl acetate:hexane 5:95)

Procedure

To a cold solution (-78° C.) of thiophene (0.07 ml, 0.75 mmol) in 1.5 ml of THF was added t-BuLi (0.457 ml, 0.75 mmol, 1.7M in pentane) and stirred for 2 h. To this solution, ZnCl2 (168 mg, 1.2 mmol) in 1.5 ml of THF was added. The resulting solution was warmed to room temperature, stirred for 1 h and was added (via cannula) to a solution of ethyl 4-[(5,6-dihydro-5,5-dimethyl-8-trifluoromethylsulfonyloxy-naphthalen-2-yl)azo]benzoate (Compound D11, 150 mg, 0.30 mmol) and tetrakis(triphenylphosphine)palladium(0) (10.6 mg) in 2.5 ml of THF. The resulting mixture was heated at 50° C. for 2.5 h. The reaction was diluted with sat. aqueous NH4Cl and extracted with ethyl acetate. The combined organic layer was dried over Na2SO4 and concentrated to an oil. The crude product was purified by flash chromatography (silica, ethyl acetate:hexane 5:95) to afford the title compound as a red foam.

Source