Yield:2752-50-3 69%

Reaction Conditions:

in sodium hydroxide;diethyl ether;

Steps:

B.35.A Step A.

Step A. Preparation of N-(Phenylacetyl)valine To a stirred solution of 5.15 g (44 mmol) of valine (Bachem) in 50 mL (100 mmol) of 2N NaOH cooled to 0° C. was added dropwise 5.3 mL (40 mmol) of phenylacetyl chloride (Aldrich). A colorless oil precipitated. The reaction mixture was allowed to warm to room temperature and stirred for 18 hours, washed with 50 mL diethyl ether, acidified to pH 2-3 with aqueous HCl. The white precipitate formed was filtered off, washed thoroughly with water, followed by diethyl ether to give 7.1 g (30 mmol, 69% yield) of the title compound. NMR data was as follows: ¹H-nmr (DMSO-d₆): δ=12.63 (s, 1H), 8.25 (d, J=8.6 Hz, 1H), 7.27 (m, 5H), 4.15 (m, 1H), 3.56 (d, J=13.8 Hz, 1H), 3.47 (d, J=13.8 Hz, 1H), 2.05 (m, 1H), 0.87 (d, J=6.8, Hz, 3H), 0.84 (d, J=6.8 Hz, 3) ¹³C-nmr (DMSO-d₆): δ=173.2, 170.4, 136.6, 129.0, 128.2, 126.3, 57.1, 41.9, 30.0, 19.2, 18.0 C₁₃H₁₇NO₃ (MW=235.29; Mass Spectroscopy (MH⁺=236))

References:

US6506782,2003,B1