Isobutyraldehyde → (R)-N-isobutylserine methyl ester HCl salt

To a suspension of (D)-serine methyl ester HCl salt (2.13 g, 13.7 mmol) in 1,2-dichloroethane was added isobutyraldehyde (1.5 mL, 16.4 mmol) and sodium triacetoxyborohydride (4.3 g, 20.5 mmol). The reaction mixture was stirred at room temp. for 24 h, then partitioned between Et2O (100 mL) and a saturated NaHCO3 solution (100 mL). The organic layer was washed with a saturated NaHCO3 solution (3×100 mL), dried (MgSO4), and treated with a 1M HCl solution in ether (25 mL). The resulting mixture was concentrated under reduced pressure to yield (R)-N-isobutylserine methyl ester HCl salt (2.27 g, 79%): NMR (DMSO-d6) δ0.94 (dd, J=6.7, 3.0 Hz, 6H); 1.97-2.11 (m, 1H); 2.76-2.91(m, 1H); 3.76 (s, 3H); 3.86 (dd, J=12.1, 4.1 Hz, 1H), 3.99 (dd, J=12.4, 3.2 Hz, 1H), 4.13-4.21 (m, 1H).

1. custompartitioned between Et2O (100 mL)
2. washThe organic layer was washed with a saturated NaHCO3 solution (3×100 mL)
3. dry with materialdried (MgSO4)
4. additiontreated with a 1M HCl solution in ether (25 mL)
5. concentrationThe resulting mixture was concentrated under reduced pressure

ORD record

ord-a9b62f5f291543c6b7d2e93783f1f71f

Source dataset

uspto-grants-2002_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06353006B1