4-Nitrobenzoic Acid → HCID 25133552, compound

Temperature

23 °C

To a mixture of (S)-8a (46 mg, 0.35 mmol), p-nitrobenzoic acid (86 mg, 0.52 mmol), and triphenylphosphine (181 mg, 0.69 mmol), diisopropylazodicarboxylate (135 μL, 0.69 mmol) was added dropwise and the resulting mixture was stirred at 23° C. overnight. The solvent was removed under reduced pressure and the residue was purified by flash-chromatography (1:3 EtOAc/Hex). The resulting ester was dissolved in a 3:2:1 mixture of THF, methanol and water (4 mL) and LiOH.H2O (72 mg, 1.7 mmol) was added. The yellow mixture was stirred at 23° C. overnight and then the solvent was removed in vacuo, the residue was diluted with water and the aqueous phase was extracted with ether. The organic extracts were dried (Na2SO4) and the solvent evaporated. Purification of the residue by flash-chromatography (EtOAc) afforded 20 mg (44%) of (R)-8c as a colourless liquid. [α]D20=+12.1 (c 1.4, CHCl3). 1H and 13C NMR are consistent with those reported for the (S)-enantiomer 8a

1. additionwas added dropwise
2. customThe solvent was removed under reduced pressure
3. customthe residue was purified by flash-chromatography (1:3 EtOAc/Hex)
4. additionwas added
5. stirringThe yellow mixture was stirred at 23° C. overnight
6. customthe solvent was removed in vacuo
7. additionthe residue was diluted with water
8. extractionthe aqueous phase was extracted with ether
9. dry with materialThe organic extracts were dried (Na2SO4)
10. customthe solvent evaporated
11. customPurification of the residue by flash-chromatography (EtOAc)
12. customafforded 20 mg (44%) of (R)-8c as a colourless liquid

ORD record

ord-87fc4c4412d443f09aead532020fc338

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08501961B2