Methanol → 1-Azabicyclo[3.2.2]nonan-4-one

An ice-cooled (5° C.) solution of tri-methylsilyldiazomethane/hexane (2N, 30 mL, 60 mmol) under nitrogen was treated dropwise with a solution of quinuclidin-3-one free base (from aqueous Na2CO3 neutralization of HCl salt followed by ether extraction, 6.26 g, 50 mmol) in anhydrous tetrahydrofuran (40 mL). Methanol (20 mL) was added, and the yellow solution was warmed to room temperature, stirred for 16 h, and quenched to colorless by addition of acetic acid (~20 drops). After a few min saturated sodium carbonate (15 mL) was added. The organic (top) layer was separated and the aqueous solution was extracted with methylene chloride (3×50 mL). The combined organic layer and extracts were dried (Mg2SO4), concentrated in vacuo, dissolved in minimal methylene chloride, and filtered through a short column of alumina (eluted with 2% methanol/methylene chloride). The filtrate was concentrated in vacuo to afford 1-azabicyclo[3.2.2]nonan-4-one (5.12 g, 74%) as an amorphous white solid.

1. customquenched
2. additionto colorless by addition of acetic acid (~20 drops)
3. additionAfter a few min saturated sodium carbonate (15 mL) was added
4. customThe organic (top) layer was separated
5. extractionthe aqueous solution was extracted with methylene chloride (3×50 mL)
6. dry with materialThe combined organic layer and extracts were dried (Mg2SO4)
7. concentrationconcentrated in vacuo
8. dissolutiondissolved in minimal methylene chloride
9. filtrationfiltered through a short column of alumina (eluted with 2% methanol/methylene chloride)
10. concentrationThe filtrate was concentrated in vacuo

ORD-Eintrag

ord-66a507b5834745679748f92e8c03aab9

Quelldatensatz

uspto-grants-1996_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05583221