Hydrochloric Acid → Methyl 8-bromo-6-fluoro-1-oxo-2,3-dihydro-1H-pyrrolo[1,2-a]indole-2-carboxylate

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Reaction Steps

To a suspension of the indole of Step 4 (4 g, 15 mmol) in a mixture of 10:1 toluene/THF (100 mL) at r.t. was added potassium t-butoxide (15 mL of a 1M solution in THF). The reaction mixture was stirred for 2 minutes and methyl acrylate (2.5 g, 30 mmol) was added. The mixture was stirred at reflux for 5 hours and cooled to r.t. Then 1N HCl was added to acidify to pH 3 and the reaction mixture was extracted with EtOAc and the combined organic layers were concentrated. The residue was swished in EtOAc/Hexanes to give 4 g of the desired compound as a pale yellow solid.

Provenance & Evidence