Hydrochloric Acid → DL-Carnitine

Temperature

80 °C

To a solution of (R)-3-acetyloxy-4-tosyloxybutanenitrile (4.07 g, 13.70 mmol) in ethanol (40 mL) was added excess aq., trimethyl amine, refluxed overnight and the solvents in the reaction mixture were evaporated. To the resulting residue was added cone. HCl and heated to 80° C. for 6 h after evaporation of the solvent the residue containing crude (R)-carnitine was purified over an on exchange column, chromatography (Amberlite IR-120 W). The column was first eluted with water until the fractions were neutral and later with 10% NH4OH. Evaporation of the basic fractions gave a thick oil, which was again acidified with cone. HCl. Evaporation of the solvent afforded carnitine as hydrochloride salt. Trituration with isopropanol afforded colourless solid of (R)-carnitine hydrochloride, m.p. 44-146° C.; [α]30D=−22.4 (c 1.5, H2O); 1HNMR (200, D2O) δ 2.60-2.70 (m, 2H), 3.24 (s, 9H); 3.48-3.55 (m, 2H); 4.60-4.75 (m, 1H); 13CNMR (75 MHz, D2O) [[n]] 39.9, 54.2, 62.8, 69.7, 173.8; Mass (FAB) 162 (M++1).

1. customthe solvents in the reaction mixture were evaporated
2. additionTo the resulting residue was added cone
3. customafter evaporation of the solvent the residue
4. additioncontaining crude (R)-carnitine
5. customwas purified over an on exchange column, chromatography (Amberlite IR-120 W)
6. washThe column was first eluted with water until the fractions
7. customEvaporation of the basic fractions
8. customgave a thick oil, which
9. customEvaporation of the solvent

ORD record

ord-9dbc813eb4ac4bfb860789b02e5c7f52

Source dataset

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07816119B2