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

Participants

Reaction Conditions

Reaction Steps

A solution of 2,5-dimethoxytetrahydrofuran (50 g, 378 mmol) in 0.025 M aqueous hydrochloric acid (160 ml) was cooled to 0° C. and stirred 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 1 hour. The mixture was heated to 50° C. for a further 90 minutes then cooled in an ice bath and basified to pH12 with 2 N aqueous sodium hydroxide solution. The layers were separated, and the aqueous phase extracted with ethyl acetate (3×). The combined organic solutions were washed with water, dried (MgSO4), filtered and evaporated under reduced pressure. The residual brown oil was distilled under reduced pressure (126° C./0.4 kPa) to afford the title compound as an off-white solid, 37.81 g.

Provenance & Evidence