Hydrochloric Acid → 4-(Pyrrolidin-1-yl)butanoic acid hydrochloride

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Reaction Steps

30.0 g. (0.13 mole) of methyl γ-iodobutyrate [F. F. Blicke, W. B. Wright and M. F. Zienty, J. Amer. Chem. Soc. 63, 2488 (1941)] was combined with 36 g. of pyrrolidine (Aldrich) in 300 ml. of benzene, heated at 60° for 0.5 hours and stirred at room temperature for 16 hours. A dark orange layer formed. The benzene solution was decanted, concentrated and distilled (b.p. 100° at 15 mmHg) to give 10 g. of colorless liquid. The infrared and nmr spectra indicated the product to be methyl γ-pyrrolidinobutyrate. This material was dissolved in 100 ml. of 18% hydrochloric acid and heated at reflux for 28 hours. The solution was concentrated under reduced pressure to give a semisolid which was triturated with acetone and filtered. Recrystallization from acetic acid/acetone gave 8.3 g. (33%) of the desired acid hydrochloride as colorless crystals, m.p. 126° - 127°. The infrared and nmr spectra and consistent with the proposed structure.

Provenance & Evidence