Sodium Hydroxide → 2-(N-methyl-3-phenylprop-2-ynoylamino)acetic acid

Participants

Reaction Steps

To a 0° C. solution of ethyl 2-(N-methyl-3-phenylprop-2-ynoylamino)acetate (prepared according to the procedure described for Intermediate A, 124.4 g, 0.507 mol) in MeOH (750 mL) was added a solution of NaOH (30.4 g, 0.760 mol, 1.5 equiv) in water (1000 mL). The resulting red reaction mixture was stirred for 20 min, then allowed to warm to room temperature and stirred for 2 h. The reaction was washed with CH2Cl2 (3×500 mL). The aqueous layer was cooled in an ice bath and acidified to pH 3 using conc. HCl. A light orange oil formed, which was extracted into EtOAc (4×500 mL). The combined EtOAc layers were washed with water (3×200 mL) and a saturated NaCl solution (2×300 mL), dried (Na2SO4) and concentrated under reduced pressure to give 2-(N-methyl-3-phenylprop-2-ynoylamino)acetic acid (102.5 g, 93%) as an orange solid: TLC (1% AcOH/5% MeOH/CH2Cl2) Rf 0.20; 1H NMR (CDCl3) δ 3.09 (s, 1.1H, N—CH3), 3.36 (s, 1.9H, N—CH3), 4.27 (s, 1.2H, N—CH3), 4.45 (s, 0.8H, N—CH3), 7.30-7.56 (m, 5H), 9.58 (br s, 1H).

Provenance & Evidence