Phenylalanine, N-[(1,1-dimethylethoxy)carbonyl]-β-hydroxy-, methyl ester synthesis

Yield:439612-08-5 62%

Reaction Conditions:

with sodium tetrahydroborate in methanol at -78; for 0.5 h;

Steps:

ervthro-m ethyl 2-((tert-butoxycarbonvl,)amino,)-3-hydroxv-3-phenylpropanoate

[007911 Prepared using General Procedure 25: To a stirred solution of methyl 2-(Qert- butoxycarbonyl)amino)-3 -oxo-3 -phenylpropanoate (0.5 g, 1.705 mmol) in MeOH (1 OmL) at -78°C was added sodium borohydride (0.045 g, 1.193 mmol). After 0.5 h, the reaction was quenched with NH4C1 (8 mL of a saturated aqueous solution) and the MeOH evaporated under reduce pressure.The mixture was extracted with DCM (2 x 30 mL) and the combined organic extracts dried over MgSO4 and solvents evaporated. The residue was purified by column chromatography (EAliso-hexanes) to afford 312 mg (62%) ofervthro-methyl 2-((tert-butoxycarbonyl)amino)-3-hydroxy-3-phenylpropanoate. LCMS-ESI (m/z) calculated for C15H21N05: 295.1; found 318.0 [M+Na1, /p. = 1.84 mm (Ivlethod 1]).

References:

WO2016/94729,2016,A1 Location in patent:Paragraph 00791