Reaction #9925

Reaction equation

3-amino-3-(3-cyclopentyloxy-4-methoxyphenyl)propanoic acid

sodium carbonate

N-ethoxycarbonyl phthalimide

→

3-(3-cyclopentyloxy-4-methoxy-phenyl)-3-phthalimidopropanoic acid

Yield 68.0%

Solvents

acetonitrile

water

Conditions

Workup

1. 1
   workup.STIRRINGThe resulting mixture was stirred at room temperature for 18 hours
2. 2
   OtherMost of solvent was removed in vacuo
3. 3
   workup.ADDITIONTo the solution was added hydrochloric acid (6N) until the pH of solution <1
4. 4
   Otherto give a suspension
5. 5
   workup.STIRRINGstirring
6. 6
   workup.WAITwas continued for 1 hour
7. 7
   FiltrationThe suspension was filtered
8. 8
   Washthe solid was washed with water (2×10 mL)
9. 9
   Otherwas dried in a vacuum oven overnight (60° C., <1 torr)

Procedure

A mixture of 3-amino-3-(3-cyclopentyloxy-4-methoxyphenyl)propanoic acid (3.00 g, 10.8 mmol) and sodium carbonate (1.20 g, 11.3 mmol) in acetonitrile (30 mL) and water (30 mL) under nitrogen was stirred at room temperature for 15 minutes. To the resulting solution was added N-ethoxycarbonyl phthalimide (2.36 g, 10.8 mmol). The resulting mixture was stirred at room temperature for 18 hours. Most of solvent was removed in vacuo. To the solution was added hydrochloric acid (6N) until the pH of solution <1 to give a suspension and stirring was continued for 1 hour. The suspension was filtered, the solid was washed with water (2×10 mL), and then was dried in a vacuum oven overnight (60° C., <1 torr) to afford 3-(3-cyclopentyloxy-4-methoxy-phenyl)-3-phthalimidopropanoic acid as a white solid (3.0 g, 68% yield): mp, 168.0–169.0° C.; 1H NMR (DMSO-d6) δ 1.55–1.88 (m, 8H, C5H8), 3.27 (dd, J=6.9, 16.5 Hz, 1H, CHH), 3.51 (dd, J=8.9, 16.5 Hz, 1H, CHH), 3.71 (s, 3H, CH3), 4.71–4.75 (m, 1H, CH), 5.61 (dd, J=6.9, 8.8 Hz, 1H, NCH), 6.87–6.95 (m, 2H, Ar), 7.03 (br s, 1H, Ar), 7.81–7.91 (m, 4H, Ar), 12.4 (br s, 1H, OH); 13C NMR (DMSO-d6) δ 23.51, 32.14, 32.17, 36.07, 50.08, 55.52, 79.57, 112.15, 113.97, 119.39, 123.17, 131.09, 131.19, 134.66, 146.77, 149.16, 167.67, 171.72; Anal Calcd for C23H23NO6: C, 67.47; H, 5.66; N, 3.42. Found: C, 67.21; H, 5.46; N, 3.45.

Source