Reacción #47852

Ecuación de reacción

5-bromothiophene-2-carboxylic acid

thionyl chloride

tert-butylamine

→

amide

Rendimiento 83.4%

5-Bromo-N-tert-butylthiophene-2-carboxamide

Rendimiento 83.4%

Disolventes

DCM

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturaunder reflux for 3 hrs
2. 2
   OtroExcess of thionyl chloride was removed by distillation under reduced pressure
3. 3
   Otrobeing kept below 10° C
4. 4
   workup.STIRRINGThe resulting solution was stirred at 25° C. for 12 hrs
5. 5
   Lavadowashed with water (3×20 ml)
6. 6
   Secadodried over MgSO4
7. 7
   Extracciónextracted with DCM (3×100 ml)
8. 8
   Secadodried over MgSO4
9. 9
   OtroThe combined organic solutions were evaporated under reduced pressure
10. 10
    Otroto give the crude product (12.5 g)
11. 11
    OtroRecrystallization from (C6H12/CHCl3)

Procedimiento

A mixture of 5-bromothiophene-2-carboxylic acid (10.0 g, 48 mmol) and thionyl chloride (3.5 ml, 48 mmol) was boiled under reflux for 3 hrs. Excess of thionyl chloride was removed by distillation under reduced pressure. The residue was taken up in DCM (30 ml) and a solution of tert-butylamine (7.0 g, 96 mmol) in DCM (30 ml) was added with stirring, the temperature of the mixture being kept below 10° C. The resulting solution was stirred at 25° C. for 12 hrs, washed with water (3×20 ml) and dried over MgSO4. The combined washings were basified to pH11 with 5M KOH(aq) and extracted with DCM (3×100 ml) and dried over MgSO4. The combined organic solutions were evaporated under reduced pressure to give the crude product (12.5 g). Recrystallization from (C6H12/CHCl3) gave the pure amide (10.5 g) as a white solid. MS (ES+): 263 (M+H)+.

Fuente