4-Nitrobenzoic Acid → (4S,2R)-4-benzoyloxypentane-2-ol

After triphenylphosphine (566 mg, 2.16 mmol), (2R,4R)-2,4-pentanediol (225 mg, 2.16 mmol), and THF (6 ml) were added to a 50 mL flask, a 40% azodicarboxylic acid diisopropyl ester-toluene solution (1.13 mL, 2.16 mmol) dissolved in THF (6 mL) was added dropwise thereto at 20° C. Subsequently, 4-nitrobenzoic acid (300 mg, 1.80 mmol) dissolved in THF (6 mL) was added dropwise thereto at 20° C., and the reaction was allowed to proceed for one hour. Water (0.5 ml) was added, and concentration was carried out. Then, water (10 ml) was added to the solution, and extraction was carried out using diethyl ether (10 mL,×2). Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml), and dehumidified with anhydrous magnesium sulfate. Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution) to give (4S,2R)-4-benzoyloxypentane-2-ol containing 1,2-hydrazinedicarboxylic acid diisopropyl ester as 593 mg of a pale yellow solid substance. Measurement of 1H-NMR showed that 379 mg of (4S,2R)-4-(4-nitrobenzoyloxy)pentane-2-ol (yield: 83%/4-nitrobenzoic acid), and 213 mg of 1,2-hydrazinedicarboxylic acid diisopropyl ester were contained.

1. additionwas added dropwise
2. customat 20° C
3. additionwas added dropwise
4. customat 20° C.
5. concentrationconcentration
6. additionThen, water (10 ml) was added to the solution, and extraction
7. washThen, the organic layer was washed with water (10 ml) and saturated salt water (10 ml)
8. customSubsequently, a crude product obtained by concentration
9. customwas purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution)

ORD record

ord-04505bda1de148a2b34af51f391a1e22

Source dataset

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07820802B2