Di-tert-butyl 3-fluoro,4-[Bis(2-(mesyloxy)ethyl)amino]benzoyl-L-glutamate → N-Benzoyl-L-glutamic acid

Participants

Reaction Steps

Compound (16) (0.10 g, 0.16 mmol), (17) (0.08 g, 0.13 mmol), or (18) (0.06 g, 0.11 mmol) was suspended in TFA (4% w/v) and stirred for 40 min at room temperature. The acid was removed under reduced pressure and the remaining oil was diluted with ethyl acetate (1 ml) which was evaporated. This latter step was repeated 5-6 times. Compound (19); yield (0.09 g, 91%) 3-fluoro, 4-[bis-[2-mesyloxy)ethyl]amino]benzoyl-L-glutamic acid, was obtained as a pure product from (16); 1H NMR (Me2 SO-d6)δ1.99 (m, 2H, CH2CH2CO2H), 2.35 (t, 2H, J=7.45 Hz, CH2CH2CO2H), 3.13 (s, 6H, (CH3 SO3)2), 3.72 (t, 4H,J=5.34 Hz, (CH3SO3CH2 CH2)2), 4.31 (t, 4H, J=5.16 Hz, (CH3SO3CH2 CH2)2), 4.39 (m, 1H, CH), 7.16 (dd, 1H, JH-5,H-6 =8.59, JH-5,F =18.03 Hz, H-5), 7.68 (dd, JH-6,H-5 =8.91, JH-2,F =15.29 Hz, H-2, H-6), 8.45 (d, 1H, J=7.69 Hz, NH); 19F NMR (Me2SO-d6) δ-122.54(m); mass spectrum (FAB) m/z (529[M+H+ ],45) 382 (M-glu, 100); Accurate mass expected 529.0961 found +5.4 ppm; Anal: C18H25N2O11FS2 -0.22TFA-0.21EtOAc requires C-40.47, H-4.74, N-4.90, F-5.51, S-11.21, found C-40.87, H-4.76, N-4.75, F-5.85, S-10.98. (The presence of EtOAc and TFA, noted in the elemental analysis was confirmed by NMR). This compound reacted positively with the Epstein spray reagent.

Provenance & Evidence