Oxalyl chloride → HCID 86625245, Verbindung

To an ice-water cooled solution of 4-phenylbicyclo[2.2.2]octane-1-carboxylic acid (479 mg, 2.07 mmol) in DCM (20 mL) was added DMF (2-3 drops) followed by oxalyl chloride (0.20 mL, 2.14 mmol). The reaction mixture was allowed to warm to ambient temperature overnight and then solvent was evaporated under reduced pressure to leave crude 4-phenylbicyclo[2.2.2]octane-1-carbonyl chloride which was used directly in the next stage. This was redissolved in a 1:1 solution of MeCN and THF (10 mL) and added dropwise to an ice water cooled solution of 2M trimethylsilyldiazomethane (1.5 mL, 3.0 mmol) and triethylamine (0.40 mL, 2.60 mmol) in a 1:1 solution of MeCN and THF (20 mL). The resulting yellow reaction mixture was allowed to stir at 0° C. for 6 hrs and then allowed to stand at ambient temperature overnight. The solvent was removed under reduced pressure and the residue redissolved in EtOAc (100 mL) and washed with water (50 mL), NaHCO3 (50 mL) and brine (50 mL). The organic phase was dried (MgSO4), concentrated to leave a red brown gum. This was purified on a 12 g silica Crawford silica cartridge, eluting 0-10%-20% EtOAc using an Isco Companion, to give 2-diazo-1-(4-phenylbicyclo[2.2.2]oct-1-yl)ethanone (238 mg; 0.933 mmol, 45%) as a pale yellow gum which formed a cream solid on standing; 1H NMR (CDCl3) δ1.82-1.91 (m, 12H), 5.38 (s, 1H), 7.15-7.21 (m, 2H), 7.29-7.31 (m, 4H); MS m/e MH+ 255.