Hydrochloric Acid → 4-(3-Amino-1,2,4-triazin-5-yl)-1-azabicyclo[2.2.1]heptane

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Reaction Steps

4-(α-bromoacetyl) -1 -azabicyclo[2.2.1 ]heptane hydrobromide (EP-0366304, Description 19) (0.5 g, 1.67 mmol) was converted into 2-oxo-2- (1-azabicyclo [2.2.1]hept-4-yl)ethanal hydrobromide as described in Example 3. The crude aldehyde was immediately treated with a suspension of aminoguanidine bicarbonate (0.25 g, 1.84 mmol) in water (10 ml) and the solution was acidified to pH6 with 5M hydrochloric acid. After stirring overnight at room temperature the reaction mixture was saturated with potassium carbonate then extracted into chloroform (4×20 ml). The combined organic extracts were dried over sodium sulphate and concentrated in vacuo. The residue was crystallised from isopropanolpentane to afford the title compound (E4) as a brown solid (0.14 g, 43%) . This was converted into the oxalate salt m.p. 178° C. (dec) (from methanol-ether).

Provenance & Evidence