Diethyl Ether → 3-Phthalimido-3-(4-benzyloxy-3-methoxyphenyl)propionic acid

Participants

Reaction Steps

To a stirred solution of 3-amino-3-(4'-benzyloxy-3'-methoxyphenyl)propionic acid (1.505 g, 5.00 mmol) and sodium carbonate (0.572 g, 5.40 mmol) in a mixture of 75 mL of water and 175 mL of acetonitrile (mixture was warmed gently to dissolve solid) was added N-carbethoxyphthalimide (1.096 g, 5.00 mmol). The mixture was stirred for 1 hour, then partially concentrated in vacuo to remove the acetonitrile. A small amount of solid formed which was removed by filtration. The pH of the solution was adjusted to 1 with 4N Hydrochloric acid, a gum formed. To the stirred mixture was added 1 mL of ether and the mixture was then stirred overnight. The resulting slurry was filtered and the solid dried to afford 1.63 g (75%) of 3-phthalimido-3-(4'-benzyloxy-3'-methoxyphenyl)propionic acid as a white powder; 1H NMR (DMSO-d6) δ 12.43 (br s, 1 H, COOH), 8.0-7.8 (m, 4 H, Ar), 7.60-7.25 (m, 5 H), 7.15-6.85 (m, 3 H, Ar), 5.25 (dd, 1 H, J=9, 6.6 Hz), 5.05 (s, 2 H, OCH2), 3.76 (s, 3 H, OMe), 3.52 (dd, 1 H, J=9, 16.5 Hz), 2.29 (dd, 1 H, J=6.6, 16.5 Hz); 13C NMR (DMSO-d6) δ 171.7, 167.6,148.9, 147.3, 137.0, 134.6, 131.7, 131.0, 128.3, 127.7, 127.6, 123.1, 119.1, 113.3, 111.3, 69.8, 55.5, 50.1, 36.0. Anal. Calcd for C25H21N1O6. Theory: C, 69.66 ; H, 4.91; N, 3.25. Found: C, 69.50; H, 4.85; N, 3.22.

Provenance & Evidence