Yield:773122-52-4 56%

Reaction Conditions:

with ammonium acetate in ethanol at 80; for 16 h;

Steps:

1.1

Step 1 : To a stirred solution of 2,5-difluorobenzaldehyde (20.0 g, 140.74 mmol, 1 equiv), malonic acid (17.56 g, 170.0 mmol, 1.2 equiv) and ammonium acetate (21.7 g, 282.0 mmol, 2 equiv) in EtOH (250 mL) was heated at 80°C for 16 h. After completion of starting material the reaction mixture was cooled to room temperature, the solid obtained was filtered and washed with n-pentane and dried to give the 3-amino-3-(2,5- difluorophenyl)propanoic acid as off white solid (16.0 g, 56.0 %). LC-MS (ES) m/z = 202.0 [M+H]⁺. H NMR (400 MHz, DMSO-d6) δ ppm 2.40 - 2.42 (m, 2 H), 4.40 (t, J = 6.0 Hz, 1 H), 5.6 - 6.8 (br. s, 2 H), 7.07 - 7.12 (m, 1 H), 7.13 - 7.21 (m, 1 H), 7.34 - 7.39 (m, 1 H).

References:

WO2017/46737,2017,A1 Location in patent:Page/Page column 90