Sodium hydride → 2-Methoxycarbonyl-1-triisopropylsilylpyrrole

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Reaction Steps

The 3-iodo-5-methoxycarbonyl-1-triisopropylsilylpyrrole starting material can be prepared as follows. Sodium hydride (80% dispersion; 660 mg, 22 mmol) was washed with pentane and suspended in tetrahydrofuran (20 mL). A solution of methyl pyrrole-2-carboxylate (1.251 g, 10 mmol) in tetrahydrofuran (10 mL) was added and the mixture stirred at room temperature. When gas evolution ceased, triisopropylsilyl chloride (1.928 mg, 10 mmol) was added dropwise, and the mixture was stirred for 1 hour, heated at reflux overnight, and partitioned between ether and water. The ethereal layer was dried (magnesium sulfate) and concentrated in vacuo. The residue was purified by chromatography using hexanes:ethyl acetate (8:1) to yield 2-methoxycarbonyl-1-triisopropylsilylpyrrole as an oil (2.05 g, 73%): 1H NMR (CDCl3) δ 7.12 (m, 2H), 6.26 (m, 1H), 3.78 (m, 3H), 1.76 (sept, 3H, J=7.6 Hz), 1.04 (d, 18 H, J=7.6 Hz).

Provenance & Evidence