N-Methoxy-N-methylbutyramide → tert-butyl 3-(5-butyryl-1-methyl-1H-indol-2-yl)pyrrolidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To solution of tert-butyl 3-(5-bromo-1-methyl-1H-indol-2-yl)pyrrolidine-1-carboxylate (1.207 g, 3.18 mmol) in THF (13 mL) at −78° C. was added solution of n-BuLi (2.5M hexanes, 1.50 mL, 3.75 mmol) dropwise over 10 min. The reaction was stirred at −78° C. for 10 min, then a solution of N-methoxy-N-methylbutyramide (0.50 g, 3.81 mmol) in THF (2.0 mL) was added dropwise. The reaction was slowly allowed to warm to −50° C. before it was quenched with NH4Cl (aqueous saturated, 10 mL). Once ambient temperature was reached in the reaction mixture, the product was extracted with EtOAc (3×20 mL). Combined organics were washed with NaCl (aqueous saturated) and dried over Na2SO4. Upon solvent removal residue was purified by column chromatography using EtOAc/hexanes (gradient 0-60%) to afford tert-butyl 3-(5-butyryl-1-methyl-1H-indol-2-yl)pyrrolidine-1-carboxylate (0.823 g) in 70% yield.

Provenance & Evidence