Hydrochloric Acid → (S)-Methyl 2-amino-3-cyclopentylpropanoate

Temperature

65 °C

(S)-2-Amino-3-cyclopentyl-propionic acid (Chemimpex, 1.0 g, 6.36 mmol), methanol (15 mL) and concentrated hydrochloric acid (2 mL) was placed in a reaction flask and heated at 65° C. for 16 h. After such time, the reaction mixture was concentrated in vacuo and then dissolved in water. The resulting solution was then treated with a saturated aqueous sodium bicarbonate solution until pH ˜7-9. It was then extracted with ethyl acetate and the organic layers combined, dried over magnesium sulfate, filtered to remove the drying agent and the filtrate concentrated in vacuo to afford (S)-2-amino-3-cyclopentyl-propionic acid methyl ester (796 mg, 73%) as a clear colorless oil: HR-ES(+) m/e calcd for C9H17NO2 [M+H]+ 172.1332, observed 172.1332; 1H NMR (300 MHz, DMSO-d6) δ ppm 3.60 (s, 3H), 3.25 (dd, J=6.04, 7.85 Hz, 1H), 1.34-1.96 (m, 9H), 0.92-1.14 (m, 2H).

1. concentrationAfter such time, the reaction mixture was concentrated in vacuo
2. dissolutiondissolved in water
3. additionThe resulting solution was then treated with a saturated aqueous sodium bicarbonate solution until pH ˜7-9
4. extractionIt was then extracted with ethyl acetate
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. customto remove the drying agent
8. concentrationthe filtrate concentrated in vacuo

ORD record

ord-0eb7dc434ea34860a40f4dcc66b89c2b

Source dataset

uspto-grants-2013_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08470866B2