Ethyl Acetate → 5-Bromo-1-(2-trimethylsilanyl-ethoxymethyl)-3-(1-trityl-1H-pyrazol-4-yl)-1H-pyrrolo[2,3-b]pyridine

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Reaction Steps

To a solution of 21 (0.5 g, 0.99 mmol) in DMF (2.5 mL) was added NaH (60% w/w in mineral oil, 59.4 mg, 1.48 mmol) portionwise. Then the reaction mixture was stirred for 0.5 h. SEM-Cl (263 μL, 1.48 mmol) was then added and the reaction mixture stirred overnight. It was poured cautiously onto a stirred mixture of ethyl acetate (20 mL)/sat. aq. NH4Cl (20 mL) and the layers separated. The aqueous layer was extracted with AcOEt (2×30 mL), the combined organic extracts dried (MgSO4) and concentrated. The residue was purified by SGC using AcOEt:hexane (gradient elution up to 8:92, v/v) to give 22 as a white foam (345 mg, 55%); 1H NMR (400 MHz, CDCl3) δ 0.002 (9H, s), 0.97 (t, J=8.3 Hz, 2H), 3.58 (t, J=8.3 Hz, 2H), 5.69 (s, 2H), 7.30 (m, 6H), 7.40 (m, 9H), 7.46 (s, 1H), 7.65 (s, 1H), 7.98 (d, J=0.7 Hz, 1H), 8.06 (d, J=2.1 Hz, 1H), 8.41 (d, J=2.2 Hz, 1H).

Provenance & Evidence