p-Toluenesulfonic acid → HCID 58986318, compound

Participants

Reaction Steps

To a cold (0° C.) solution of 1-benzyl-5-hydroxy-2-isopropyl-1H-indole-3-carboxylic acid, ethyl ester (Compound 1, 2.3 gm, 6.82 mmol) in CH2Cl2 (31 mL) was added dihydropyran (DHP, 3.1 g, 36.9 mmol) and p-TsOH (50 mg). The cooling bath was removed, and the solution was stirred at ambient temperature for 16 h. The reaction was quenched by adding aqueous NaHCO3 (20 mL) and CH2Cl2 (50 mL). The layers were separated, and the organic layer was washed with brine (20 mL), and dried (MgSO4), and solvent removed under vacuum. The crude mixture was purified by silica gel flash chromatography by eluting with 10% EtOAc in hexanes to isolate 1-benzyl-2-isopropyl-5-(tetrahydropyran-2-yloxy)-1H-indole-3-carboxylic acid, ethyl ester (Compound 11) as a thick pale yellow oil.

Provenance & Evidence