Benzyl chloroformate → Tert-butyl 2-(((benzyloxy)carbonyl)amino)-3-(4-hydroxy-3-methoxyphenyl)propanoate

Participants

Reaction Steps

Prepared using General Procedure 2: To a stirred solution of tert-butyl 2-amino-3-(4-hydroxy-3-methoxyphenyl)propanoate INT-1 (5.29 g, 19.8 mmol) and TEA (4.29 mL, 29.7 mmol) in DCM (50 mL) at 0° C. was treated with benzyl carbonochloridate (3.00 mL, 21.1 mmol) dropwise over 5 min. After stirring for 10 min, the mixture was washed with 1M HCl (150 mL), dried over MgSO4, and concentrated. The residue was taken up in MeOH (20 mL) and treated with 2 N NaOH (5 mL). After 10 min, the mixture was acidified and the product was purified by chromatography (EA/hexanes) to afford 4.7 g (59%) of tert-butyl 2-(((benzyloxy)carbonyl)amino)-3-(4-hydroxy-3-methoxyphenyl)propanoate INT-2. LCMS-ESI (m/z) calculated for C22H27NO6: 401; found 424 [M+Na]+, tR=2.47 min (Method 6).

Provenance & Evidence