反应详情

A solution of 8-methyl-8-azabicyclo[3.2.1]octane-2,3-dione-2-oxime (0.93 g, 5.5 mmol) in acetic acid/acetic anhydride (4:1, 40 mL) in a Parr bottle was treated with Raney nickel (Aldrich, 1/2 tsp.), then subjected to hydrogenation in a Parr apparatus at 45-50 psi for 5 h The solution was carefully evacuated of hydrogen, filtered through Celite® (wash filter cake carefully with methanol), and the filtrate was concentrated in vacuo. The residue was taken up in toluene and reconcentrated to remove most of the acetic acid. This residue was taken up in saturated sodium carbonate (40 mL), then treated with 15% sodium hydroxide (2 mL) and extracted with methylene chloride (3×50 mL) containing some 2-propanol. The combined extracts were dried (Na2SO4), concentrated in vacuo, and chromatographed on silica gel (eluted with 1:1 ethyl acetate/methanol) to afford a white solid, which contained some silica gel. This was removed by dissolving the product in warm ethyl acetate, filtering, and concentration in vacuo to afford 2-acetamido-8-methyl-8-azabicyclo[3.2.1]octan-3-one (0.53 g, 49%) as a white solid.

1. customThe solution was carefully evacuated of hydrogen
2. filtrationfiltered through Celite® (
3. washwash
4. filtrationfilter cake carefully with methanol), and the filtrate
5. concentrationwas concentrated in vacuo
6. customto remove most of the acetic acid
7. additiontreated with 15% sodium hydroxide (2 mL)
8. extractionextracted with methylene chloride (3×50 mL)
9. additioncontaining some 2-propanol
10. dry with materialThe combined extracts were dried (Na2SO4)
11. concentrationconcentrated in vacuo
12. customchromatographed on silica gel (eluted with 1:1 ethyl acetate/methanol)
13. customto afford a white solid, which
14. customThis was removed
15. dissolutionby dissolving the product in warm ethyl acetate
16. filtrationfiltering
17. concentrationconcentration in vacuo