Reacción #1824331

Ecuación de reacción

methyl iodide

cycloheptanecarboxylic acid

diisopropylamine

n-butyllithium

→

1-methylcycloheptanecarboxylic acid

Disolventes

water ether

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   Temperaturabefore refluxing for a further 2 hours
3. 3
   TemperaturaThe reaction was cooled to 0° C.
4. 4
   Temperaturabefore refluxing for a further 1 hour
5. 5
   Temperaturabefore cooling to room temperature
6. 6
   Otrothe aqueous layer was separated
7. 7
   Extracciónextracted with ether (5×25 ml)
8. 8
   LavadoThe combined ether layers were washed with water (2×50 ml) and saturated sodium chloride solution (50 ml)
9. 9
   Secadobefore being dried over MgSO4
10. 10
    FiltraciónFiltration and evaporation of solvent under reduced pressure

Procedimiento

To a stirred solution of diisopropylamine (7.47 g, 73.8 mmol) in dry THF at -78° C. under nitrogen was added n-butyllithium(2.5M, 29.5 ml, 73 8 mmol). The mixture was stirred for 10 minutes before cycloheptanecarboxylic acid (2.10 g, 14.8 mmol) was added dropwise and the reaction stirred at -78° C. for a further 10 minutes before refluxing for a further 2 hours. The reaction was cooled to 0° C. and methyl iodide (5.76 g, 40.6 ml) was added dropwise before refluxing for a further 1 hour before cooling to room temperature. The reaction mixture was poured onto an admixture of water/ether (100 ml/SO ml) and the aqueous layer was separated, acidified with dilute hydrochloric acid (2M) and extracted with ether (5×25 ml). The combined ether layers were washed with water (2×50 ml) and saturated sodium chloride solution (50 ml) before being dried over MgSO4. Filtration and evaporation of solvent under reduced pressure yielded the 1-methylcycloheptanecarboxylic acid which was recrystallised from hexane (2.20 g, mp 46° C.). The title compound was produced by the method of Example 24 using this acid in place of the 1-methylcyclopentanecarboxylic acid.

Fuente