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

30.0 g. (0.13 mole) of Methyl γ-iodobutyrate (Blicke et al., J. Am. Chem. Soc. 63, 2488 (1941)) was combined with 36 g. of pyrrolidine in 300 ml. of benzene, heated at 60°C. for 0.5 hour and stirred at room temperature for 16 hours. A dark orange layer formed. The benzene solution was decanted, concentrated and distilled (b.p. 100°C. at 15 mm Hg) to give 10 g. of colorless liquid. The infrared and nuclear magnetic resonance spectra indicated the product to be methyl γ-pyrrolidino-butyrate. 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 semi-solid 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°C. The infrared and nuclear magnetic resonance spectra were consistent with the proposed structure.

1. customA dark orange layer formed
2. customThe benzene solution was decanted
3. concentrationconcentrated
4. distillationdistilled (b.p. 100°C. at 15 mm Hg)
5. customto give 10 g
6. dissolutionThis material was dissolved in 100 ml
7. temperatureat reflux for 28 hours
8. concentrationThe solution was concentrated under reduced pressure
9. customto give a semi-solid which
10. customwas triturated with acetone
11. filtrationfiltered
12. customRecrystallization from acetic acid/acetone
13. customgave 8.3 g

ORD record

ord-b00d8a8b1c5a4db6b5fb77312f4b98e6

Source dataset

uspto-grants-1976_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03941782