Reacción #1702098

Ecuación de reacción

nBuLi

I2

5-(3,3-Dimethyl-but-1-ynyl)-thiophene-2-carboxylic acid

→

5-(3,3-Dimethyl-but-1-ynyl)-3-iodo-thiophene-2-carboxylic acid

Rendimiento 65.0%

Disolventes

THF

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONAfter addition
2. 2
   workup.WAITAfter a further 10 mins
3. 3
   Otrothe reaction was quenched with 1 N HCl (50 mL)
4. 4
   Temperaturawarmed to room temperature
5. 5
   OtroThe volatiles were removed in vacuo
6. 6
   workup.DISSOLUTIONthe residue was dissolved in ether (500 mL)
7. 7
   LavadoThe organic solution was washed with 1 M Na2S2O3 (100 mL×2), brine (100 mL)
8. 8
   Secadodried over Na2SO4
9. 9
   ConcentraciónAfter concentrated in vacuo
10. 10
    Otrothe residue was purified by silica gel chromatography (EtOAc/hexanes)

Procedimiento

To a solution of 5-(3,3-Dimethyl-but-1-ynyl)-thiophene-2-carboxylic acid (6.2 g, 30 mmol; see patent application U.S. Pat. No. 5,861,421) in THF (100 mL) was added a solution of nBuLi (2.0 M in pentane, 33 mL, 66 mmol) via an addition funnel at −78° C. After addition, the reaction was stirred at −78° C. for 1 h. A solution of I2 (7.7 g, 30 mmol) in THF (100 mL) was added slowly (ca. 15 min) to the flask. After a further 10 mins, the reaction was quenched with 1 N HCl (50 mL) and warmed to room temperature. The volatiles were removed in vacuo and the residue was dissolved in ether (500 mL). The organic solution was washed with 1 M Na2S2O3 (100 mL×2), brine (100 mL) and dried over Na2SO4. After concentrated in vacuo, the residue was purified by silica gel chromatography (EtOAc/hexanes) to give 5-(3,3-Dimethyl-but-1-ynyl)-3-iodo-thiophene-2-carboxylic acid (5.9 g, 65%) as a white solid.

Fuente