Cesium bicarbonate → 4-{2-[(2E)-3-(Methoxycarbonyl)prop-2-enoyloxy]acetylamino}butanoic acid

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Reaction Steps

Following general procedure A, methyl hydrogen fumarate (MHF) (0.56 g, 4.33 mmol) dissolved in NMP was reacted at ca. 55° C. with tert-butyl 4-(2-chloroacetylamino)butanoate (0.85 g, 3.61 mmol) in the presence of CsHCO3 (0.98 g, 5.05 mmol) of the tert-butyl-protected intermediate and then purified by silica gel column chromatography (Biotage) using a mixture of ethyl acetate (EtOAc) and hexanes (1:1) as eluent. The purified product was treated with 50% trifluoroacetic acid (TFA) in dichloromethane (DCM). Removal of solvents afforded 0.45 g (46% yield) of the title compound (7). 1H NMR (CD3OD, 400 MHz): δ 6.94-6.91 (m, 2H), 4.65 (s, 2H), 3.81 (s, 3H), 3.28 (t, J=6.8 Hz, 2H), 2.33 (t, J=7.2 Hz, 2H), 1.81 (p, J=7.1 Hz, 2H). MS (ESI): m/z 274.03 (M+H)+272.06 (M−H)−.

Provenance & Evidence