Hydrochloric Acid → HCID 44210009, compound

Participants

Reaction Steps

(±) 3-(α-Bromoacetyl)-1-azabicyclo [2.2.2 ]octane hydrobromide (EP-0366304, Description 7) (1.0 g, 3.2 mmol) was converted into (±) 2-oxo-2-(1-azabicyclo[2.2.2]octan-3-yl)ethanal hydrobromide using the method described in Example 3. The crude aldehyde was immediately treated with a suspension of aminoguanidine bicarbonate (0.48 g, 3.5 mmol) in water (10 ml), and the solution was acidified to pH4 with 5M hydrochloric acid. The reaction mixture was stirred overnight at room temperature then heated under reflux for 1 h. It was then saturated with potassium carbonate and extracted into chloroform (4×10 ml). The combined organic extracts were dried over sodium sulphate, concentrated in vacuo and the residue chromatographed on neutral alumina in a gradient of 0-8% methanol in chloroform. This afforded the title compound (E6) as a colourless solid (42 mg, 6%) which was converted into the oxalate salt m.p. 175° C. (dec) (from methanol - ether).

Provenance & Evidence