2-Bromo-2-methylpropionyl bromide → Methyl {4-[4-(2-bromo-2-methylpropanoyl)phenyl]bicyclo[2.2.2]oct-1-yl}acetate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To an ice water cooled solution of crude methyl (4-phenylbicyclo[2.2.2]oct-1-yl)acetate (Intermediate 16; 961 mg, 3.53 mmol) in DCM (10 mL) was added aluminium chloride (1.4 g, 10.58 mmol) followed by the dropwise addition of 2-bromoisobutyryl bromide (0.45 mL, 3.53 mmol). The reaction mixture was allowed to stir at ˜0° C. for ˜40 mins, it was then poured onto ice-water (˜100 mL). The organic phase was separated and the aqueous phase washed with DCM (3×50 mL), the organic washings were combined, dried (MgSO4) and concentrated to leave a yellow gum. This was purified on a 120 g silicyle silica cartridge, loading in DCM and eluting with 0-10%-20% isohexane-EtOAc, the product eluting at 10% EtOAc. The mixed fractions were combined and recolumned on a 120 g silica cartridge as described above; to yield the title compound as a white solid, (705 mg 1.67 mmol, 47%). 1H NMR (CDCl3) δ 1.09 (d, 3H), 1.50-1.57 (m, 3H), 1.67-1.74 (m, 3H), 1.82-1.86 (m, 6H), 2.03 (s, 6H), 2.27 (q, 1H), 3.67 (s, 3H), 7.37 (d, 2H), 8.11 (d, 2H); GC-MS CI m/e MH+ 421.

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