3-(2-Nitrophenyl)-2-oxopropanoic acid → 2-Hydroxy-3-(2-nitrophenyl)propanoic acid

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Reaction Steps

To a magnetically stirred solution of α-oxo-2-nitrobenzenepropanoic acid (40.00 g) in absolute ethanol (500 ml) cooled in ice water was added sodium borohydride (20.0 g) in portions at such a rate as to maintain the temperature between 25 and 30°. The temperature of the solution was maintained between 25°-30° for a further 4 hours after the addition. The solution was evaporated to near dryness, and the residue was dissolved in water. The solution was acidified with concentrated hydrochloric acid and extracted four times with ethyl acetate. The organic extract was washed twice with water and dried over magnesium sulfate. Evaporation gave a syrup which was crystallized (seeding) from dichloromethane-cyclohexane; yield 28.26 g (70%), m.p. 87-90°. Recrystallization with decolorization from water gave 20.31 g (50%) of the titled compound; m.p. 104°-105°; MH+ 212 (CI mode), λmaxKBr 1715 (COOH), 3445 (OH) cm-1 ; pmr (CDCl3, DMSO-d6) δ 3.04-3.72 (8 lines, AB part of an ABX system, --CH2 --), 4.34-4.54 (q centered at 4.45, width 12 Hz, symmetrically spaced, X part of ABX system, --CH(OH)), 7.28-7.68 (m, 3 aromatic protons and exchangeable OH), 7.80-8.00 ("d" centered at 7.95, "J" 8 Hz, 1 aromatic proton).

Provenance & Evidence