Diisopropylethylamine → (R)-3-(3-(4-(Benzyloxy)phenyl)ureido)-4-(trimethylammonio)butanoate acetate

Participants

Reaction Steps

A solution of aminocarnitine (35 mg) in anhydrous MeOH (2 mL) was treated with DIPEA (2.5 equiv) and 1-(benzyloxy)-4-isocyanatobenzene (2 equiv) at rt. The reaction was sealed and stirred at rt overnight. The reaction mixture were concentrated under reduced pressure and purified on silica gel using MeOH/DCM (0->80%) and/or 55% DCM:22% MeOH:23% AcOH. The purified material was then taken into 10% MeOH/DCM, filtered through a plug of Celite, concentrated under reduced pressure and optionally triturated with Et2O and/or hexanes to provide the title compound as a white solid (1.8 mg). 1H NMR (400 MHz, CD3OD): δ=7.42 (d, J=8.0 Hz, 2H), 7.36 (t, J=7.6, 2H), 7.30 (d, J=7.60 Hz, 1H), 7.28-7.20 (m, 2H), 6.92 (d, J=8.80 Hz, 2H), 5.04 (s, 2H), 5.59 (br s, 1H), 3.80-3.45 (m, 2H), 3.21 (s, 9H), 2.60-2.45 (br, 2H), 1.96 (s, 3H); MS ESI [M+H]+, calcd for [C21H26N3O4+H]+ 386.5 found m/z 386.2 (100).

Provenance & Evidence