Imidazole → 2-bromo-(R)-1-tert-butyldimethylsiloxy-1-(3-formamido-4-benzyloxyphenyl)ethane

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To a solution of N-[2-benzyloxy-5-(2-bromo-1-hydroxyethyl)phenyl]formamide (Organic Process Research and Development 1998, 2, 96-99) (4.12 g, 11.8 mmol) in N,N-dimethylformamide (25 mL) at RT under N2 was added tert-butyldimethylsilyl chloride (3.50 g, 23.2 mmol), imidazole (1.90 g, 27.9 mmol) and 4-(dimethylamino)pyridine (40 mg, 330 □mol). The resulting solution was stirred at RT overnight, the solvent was removed and the product taken up in ethyl acetate (70 mL). The organics were washed with water (100 mL), and the aqueous extracted with ethyl acetate (20 mlmL The combined organics were washed with hydrochloric acid (2M, 50 ml), brine (100 mL) and dried (MgSO4). The crude material was purified by chromatography (5-25% ethyl acetate in pentane) to yield a colourless oil (5.7 g). 1HNMR (CDCl3, 400 MHz) δ: −0.08 to −0.05 (3H, m), 0.09-0.11 (3H, s), 0.89-0.90 (9H, m), 3.38-3.55 (2H, m), 3.78-3.84 (1H, m), 5.06-5.11 (2H, m), 6.90-6.97 (1H, m), 7.03-7.12 (1H, m), 7.24 (m), 7.36-7.43 (5H, m), 7.67-7.78 (m), 7.88 (d), 8.74 (d); LRMS APCI m/z 464/466 [M+H]+

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