4-Nitrobenzoic Acid → HCID 86584130, compound

Participants

Reaction Steps

To a cold (ice bath) solution of commercially available (R)-2-hydroxy-4-phenyl-butyrate, ethyl ester (1.86 mL, 9.60 mmole), p-nitrobenzoic acid (6.42 g, 38.4 mmole, 4 eq) and triphenylphosphine (10.07 g, 38.4 mmole, 4 eq.) in anhydrous tetrahydrofuran (110 mL) was added diethyl azodicarboxylate (6.05 mL, 38.4 mmole, 4 eq) dropwise over a period of 40 minutes keeping the internal temperature between 4 and 5° C. After stirring for one additional hour, the ice bath was removed and the solution was allowed to stir at ambient temperature for 5 days. The solvents were removed and the residue was redissolved in a mixture of ether and ethyl acetate (600 mL). Silica gel (200 mL) was added and the solvents removed. The adsorbate was flash chromatographed (gradient: 80/20- 70/30 petroleum ether/ethyl acetate) to give the title compound as a yellow oil (4.03 g): NMR (CDCl3); δ8.30 (d, J=9 Hz, 2 H), 8.18 (d, J=9 Hz, 2 H), 7.38 - 7.18 (m, 5 H), 5.28 (t, J=2 Hz, 1 H), 4.23 (q, J=7 Hz, 2 H), 2.85 (t, J=8Hz, 2 H), 2.40 - 2.33(m, 2 H), 1.29 (t, J=7 H, 3 H); MS [(+) FAB]: [M +H] m/z =358.

Provenance & Evidence