Carnitine Chloride → DL-Carnitine

Participants

Reaction Steps

A solution of DL-carnitine hydrochloride (1.0 g, 5.05 mmol) and sodium hydroxide (0.303 g, 7.58 mmol) in ethanol (15 ml) was stirred at room temperature for 2 h. The formed white precipitate (NaCl) was removed by filtration, and the solvent was evaporated under reduced pressure to give a white solid, carnitine inner salt. A suspension of the carnitine inner salt and 1 -iodooctadecane (2.31 g, 6.06 mmol) in DMF-dioxane (3:5, 40 ml) was heated with an oil-bath at 120° C. under Ar2 for 4 h. The solvent was removed by rotavapor and vacuum, and the residue was chromatographied with silica gel column using CH3OH--CH3Cl as eluant to give 2.22 g (81%) of stearyl carnitine ester as a white solid: 1H NMR (CDCl3) δ4.79 (m, 1 H), 4.43 (d, J=5.3, 1 H), 4.09 (t, J=6.9, 2 H), 4.03 (d, J=13.0, 1 H), 3.67 (dd, J=10.3, 13.3, 1 H), 3.51 (s, 9 H), 2.79 (dd, J=5.7, 17.0, 1 H), 2.66 (dd, J=7.0, 17.1, 1 H), 1.80-1.60 (m, 4 H), 1.26 (broad s, 28 H), 0.88 (t, J=6.6, 3 H). LSIMS (NBA): m/e 414.4 for C25H52NO3 (cation).

Provenance & Evidence