Sodium Carbonate → HCID 86589109, compound

To a stirred solution of (2S,3S)-4-fluorothreonine 101 (0.100 g, 0.82 mmol) in THF/H2O (1:1, 5 ml) adjusted to pH 9 using sodium carbonate was added N-carboxybenzyloxysuccinimide (0.308 g, 1.24 mmol). After stirring the solution for 18 hours at room temperature, the solvent was removed in vacuo to give a white residue. The residue was partitioned between ethyl acetate (5 ml) and water (10 ml). The organic layer was separated and aqueous layer further extracted with ethyl acetate (2×5 ml), this organic phase was discarded. The pH of the aqueous layer was adjusted to 3 using 1N HCl. The aqueous layer was extracted with ethyl acetate (4×10 ml), the combined organic layers were dried (MgSO4) and the solvent removed in vacuo to afford N-carboxybenzyloxy-(2S,3S)-4-fluorothreonine 102 as a pale yellow oil (110 mg, 70% yield); 1H (400 MHz, CDCl3) 8.20 (1H, bs, OH, exchange with CH3OD), 6.46, 6.45 and 6.07 (1H, 3×d, J 8.9), 5.10-4.85 (2H, m, CH2Ph), 4.65-4.25 (4H, H-2, H-3 and 4-CH2); 19F (376 MHz, CDCl3) −228.59 and −228.51 (2×dtJ 46,14 due to rotamers).

1. customthe solvent was removed in vacuo
2. customto give a white residue
3. customThe residue was partitioned between ethyl acetate (5 ml) and water (10 ml)
4. customThe organic layer was separated
5. extractionaqueous layer further extracted with ethyl acetate (2×5 ml)
6. extractionThe aqueous layer was extracted with ethyl acetate (4×10 ml)
7. dry with materialthe combined organic layers were dried (MgSO4)
8. customthe solvent removed in vacuo

ORD record

ord-54f05ef0de4349b486626b8149a58d0d

Source dataset

uspto-grants-2008_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07335792B2