Reacción #74390

Ecuación de reacción

(4S)-2-bromobicyclo[2.2.1]heptane-1-carboxylic acid

→

bicyclo[2.2.1]heptane-1-carboxylic acid

Rendimiento 81.3%

Disolventes

acetic acid

acetic acid

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroA 2-L reactor equipped with an overhead mechanical stirrer, condenser, nitrogen gas inlet port, temperature probe and reagent
2. 2
   workup.ADDITIONwas then added
3. 3
   Lavadoto rinse the walls of the reactor
4. 4
   Temperaturaa gentle reflux (ca. 30 min)
5. 5
   TemperaturaThe cooled
6. 6
   Otro(room temperature) reaction mixture
7. 7
   Lavadowas washed with acetic acid (1 (300 mL) and ethyl acetate (1 (500 mL)
8. 8
   ConcentraciónThe filtrate was concentrated
9. 9
   workup.ADDITIONwater (300 mL) was added
10. 10
    Otroprecipitation
11. 11
    FiltraciónThe precipitate was collected by filtration
12. 12
    Lavadowashed with water
13. 13
    Otrodried under vacuum at 35° C. overnight
14. 14
    workup.ADDITIONPentane (50 mL) was then added
15. 15
    workup.STIRRINGthe mixture was stirred vigorously for 20 min during which time a fine white precipitate
16. 16
    Otroformed
17. 17
    FiltraciónThe resulting precipitate was filtered
18. 18
    Lavadowashed with pentane (20 mL), and air
19. 19
    Otrodried

Procedimiento

A 2-L reactor equipped with an overhead mechanical stirrer, condenser, nitrogen gas inlet port, temperature probe and reagent charging port, was placed under an atmosphere of nitrogen. The reactor was charged with zinc powder (<10 micron) (298 g, 4560 mmol) and acetic acid (500 mL). While vigorously stirring the heterogeneous mixture, (4S)-2-bromobicyclo[2.2.1]heptane-1-carboxylic acid (100 g, 456 mmol) was then added. A second portion of acetic acid (500 mL) was then used to rinse the walls of the reactor. The reaction mixture was brought to a gentle reflux (ca. 30 min) and then held at this temperature for 5 h. The cooled (room temperature) reaction mixture was passed through a pad of Celite, which was washed with acetic acid (1 (300 mL) and ethyl acetate (1 (500 mL). The filtrate was concentrated, water (300 mL) was added, and then the mixture was stirred vigorously to induce precipitation. The precipitate was collected by filtration, washed with water, and dried under vacuum at 35° C. overnight. Pentane (50 mL) was then added, and the mixture was stirred vigorously for 20 min during which time a fine white precipitate formed. The resulting precipitate was filtered, washed with pentane (20 mL), and air dried to afford bicyclo[2.2.1]heptane-1-carboxylic acid (52 g) as a white solid.

Fuente