3-Benzyloxy-1-[(phenylbenzylcarbamoyl)methyl]-2-(1H)-pyridinone → 3-Hydroxy-1-[(phenylbenzylcarbamoyl)methyl]-2-(1H)-pyridinone

Participants

Reaction Steps

18 (280 mg, 0.7 mmol) was suspended in 150 mL of EtOH. 10% (w/w, 38 mg) of 10% Pd/C catalyst was added to the hydrogenation flask (500 mL Pyrex® Parr reaction bottle tested to 120 psi, max. working pressure of 60 psi). The Parr hydrogenation system located in the VanNieuwenhze lab was used for the deprotection reactions. The hydrogen pressure was set to 35 psi with agitation, and the process went on for 19 h. A white precipitate was present even after the reaction was stopped, but this white product reacted with iron(III) to give a pink product instead of no reaction as with the protected starting material. The catalyst was removed by vacuum filtration and separated from the product by dissolving the white precipitate in 100 mL hot CH2Cl2. An additional batch of product was isolated by cooling the EtOH filtrate to 0° C. for 2 h. The clear solution was concentrated by rotary evaporation to yield a white solid. The solid was washed with MeOH to remove residual DCU. Yield: 22%. 1H NMR (d6-DMSO, 400 MHz, 25° C.): δ 4.34 (d, J=6.0 Hz, 2H, —CH2—), 4.63 (s, 2H, —CH2—), 6.08 (t, J=7.2 Hz, 1H, Ar—H), 6.69 (d, J=7.2 Hz, 1H, Ar—H), 7.10 (d, J=6.4 Hz, 1H, Ar—H), 7.44 (m, 5H, Bz-H), 7.64 (m, 4H, Phenyl-H), 8.70 (t, J=5.6 Hz, 1H, —NH—), 9.02 (s, 1H, —OH). APCI-MS: m/z 334.9 [M+H]+. Anal. Calcd for C20H18N2O3: C, 71.84; H, 5.43; N, 8.38. Found: C, 71.49; H, 5.78; N, 8.52.

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