Mesoxalic acid → 8-Benzyl-8-azabicyclo(3.2.1)octan-3-one

A solution of 2,5-dimethoxytetrahydrofuran (50 g, 378 mmol) in hydrochloric acid (0.025 N, 160 ml) was cooled to 0° C. for 16 hours. Benzylamine hydrochloride (65 g, 453 mmol), ketomalonic acid (55 g, 377 mmol) and an aqueous solution of sodium acetate (300 ml, 0.69 M) were added and the reaction stirred at room temperature for one hour. The mixture was heated to 50° C. for further 90 minutes, then cooled in an ice bath and basified to pH12 with 2N sodium hydroxide solution. The layers were separated and the aqueous phase extracted with ethyl acetate (3×300 ml). The combined organic extracts were washed with water, dried (MgSO4), filtered and evaporated under reduced pressure. The residual brown oil was distilled under reduced pressure (126°/3 mmHg) to afford the title compound as an off-white solid (37.81 g).

1. temperatureThe mixture was heated to 50° C. for further 90 minutes
2. temperaturecooled in an ice bath
3. customThe layers were separated
4. extractionthe aqueous phase extracted with ethyl acetate (3×300 ml)
5. washThe combined organic extracts were washed with water
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. customevaporated under reduced pressure
9. distillationThe residual brown oil was distilled under reduced pressure (126°/3 mmHg)

ORD record

ord-6be2cce0d1104ea48747ec03a8e4c222

Source dataset

uspto-grants-2005_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06855724B2