Reaction #312569

Reaction equation

benzophenone imine

cesium carbonate

HCl

Trifluoro-methanesulfonic acid 3-(2-benzyl-2-aza-bicyclo[3.3.1]non-5-yl)-phenyl ester

→

title compound

Yield 62.3%

3-(2-Benzyl-2-aza-bicyclo[3.3.1]non-5-yl)-phenylamine

Yield 62.3%

Solvents

THF

—

hexanes

THF

THF

Conditions

Workup

1. 1
   OtherThe reaction vessel was degassed
2. 2
   Other(evac./N2 purge 3×)
3. 3
   workup.ADDITIONwere introduced
4. 4
   Temperaturethe reaction was warmed to 80° C. for 60 h. at which point it
5. 5
   TemperatureThe reaction was cooled
6. 6
   Filtrationfiltered through Celite
7. 7
   Washrinsed with THF
8. 8
   Concentrationconcentrated
9. 9
   workup.DISSOLUTIONThe resulting oil was dissolved in CH2Cl2 (200 mL)
10. 10
    Washwashed with water (100 mL) and saturated aqueous NaCl solution (100 mL)
11. 11
    Otherdried through a cotton plug
12. 12
    Concentrationconcentrated
13. 13
    Otherto give the crude product
14. 14
    Temperaturethis stirred solution was warmed to 65° C. for 60 min
15. 15
    FiltrationThe resulting orange solid is filtered
16. 16
    Other(On occasion an orange gum separates and is separated by decantation or filtration
17. 17
    Other) The biphasic filtrate was separated
18. 18
    ExtractionThe aqueous layer was extracted with Et2O (150 mL)
19. 19
    Extractionthe product was extracted with CH2Cl2 (5×40 mL)
20. 20
    Washwashed with saturated aqueous NaCl solution (1×30 mL)
21. 21
    Dryingdried over Na2SO4
22. 22
    Concentrationconcentrated
23. 23
    Otherto give the crude product

Procedure

Trifluoro-methanesulfonic acid 3-(2-benzyl-2-aza-bicyclo[3.3.1]non-5-yl)-phenyl ester (13.33 g, 30.33 mmol) was azeotroped with THF (2×50 mL) then dissolved in anhydrous THF (150 mL) with benzophenone imine (6.3 mL, 17.61 mmol), cesium carbonate (14.23 g, 43.67 mmol) and BlNAP (racemic, 1.89 g, 3.03 mmol). The reaction vessel was degassed (evac./N2 purge 3×) before charging with palladium (11) acetate (410 mg, 1.82 mmol). The reaction was warmed to 80° C. for 18 h, at which point it was judged incomplete by APCl MS. After cooling additional BlNAP (racemic, 1.89 g, 3.03 mmol) and palladium (11) acetate (410 mg, 1.82 mmol) were introduced and the reaction was warmed to 80° C. for 60 h. at which point it was judged complete by APCl MS. The reaction was cooled and filtered through Celite, rinsed with THF and concentrated. The resulting oil was dissolved in CH2Cl2 (200 mL), washed with water (100 mL) and saturated aqueous NaCl solution (100 mL), dried through a cotton plug and concentrated to give the crude product. To this was added fresh THF (150 mL) followed by 2N HCl (150 mL) and this stirred solution was warmed to 65° C. for 60 min then at room temperature for 18 h. The reaction mixture was treated with hexanes (150 mL). The resulting orange solid is filtered. (On occasion an orange gum separates and is separated by decantation or filtration.) The biphasic filtrate was separated and the hexane layer discarded. The aqueous layer was extracted with Et2O (150 mL) and the Et2O layer discarded. The aqueous layer was then neutralized with 25% aqueous NaOH solution to achieve pH 9 and the product was extracted with CH2Cl2 (5×40 mL), washed with saturated aqueous NaCl solution (1×30 mL), dried over Na2SO4 and concentrated to give the crude product. Flash chromatography provided the title compound as a thick yellow oil (3.36 g, 36%). (TLC 50% EtOAc/hexanes Rf 0.30); 1H NMR (400 MHz, CDCl3) δ 7.24 (m, 2H), 7.36 (m, 2H), 7.26 (m, 2H), 7.07 (t, J=7.9 Hz, 1H), 6.71 (dd, J=7.9, 1.6 Hz, 1H). 6.64 (m, 1H), 6.50 (dd, J=7.9, 2.0 Hz, 1H), 3.80 (m, 2H), 3.61 (m, 1H), 3.15 (m, 2H), 2.80 (m, 1H), 2.17 (br d, J=14.2 Hz, 2H), 2.00 (m, 3H), 1.79 (br d, J=12.5 Hz, 1H), 1.72 (m, 1H), 1.64 (m, 1H), 1.38 (m, 1H); APCl MS m/z 307.1 (M+1)+.

Source