Oxalic Acid → HCID 22715177, compound

Participants

Reaction Steps

To a tetrahydrofuran solution of the iodo intermediate from Example 27 step (e) (30 ml, 1.42 mmol), was added dropwise a solution of sodium azide (0.28 g, 4.26 mmol) in dimethyl sulphoxide (5 ml). The reaction was then stirred for 22hat room temperature. The solution was then treated with triphenylphosphine (1.12 g, 4.26 mmol) and water (5 ml) and stirred for 24hat room temperature. Aqueous saturated sodium bicarbonate solution (30 ml) was added and the mixture extracted with ethyl acetate (3×70 ml). The combined extracts were washed with water (2×30 ml), dried (sodium sulphate) and evaporated. The residue was dissolved in methanol, applied to a CC SCX resin, washed with methanol (200 ml) and then eluted with 7N ammonia in methanol (100 ml). The solvent was removed in vacuo and the residue-chromatographed on flash silica, eluting with 7% 7N ammonia in methanol in dichloromethane. The product was dissolved in methanol, treated with one equivalent of oxalic acid, stirred for ten minutes and then the solvent was removed in vacuo. The solid residue was recrystallised from isopropanol to give the title compound as a white solid (0.26 g, 47%).

Provenance & Evidence