反应详情

A solution of 3-(4-cyano-2-ethyl-6-methyl-phenyl)-propionic acid ethyl ester (55.0 g, 224 mmol) in THF (220 mL) and 1N aq. NaOH solution (220 mL) is stirred at rt for 2 before it is diluted with water (200 mL) and extracted with DCM (2×200 mL). The aqueous phase is added to 32% aq. HCl solution (50 mL) at 15-30° C. A precipitate forms. The solid material is collected, washed with water and dried under high vacuum to give 3-(4-cyano-2-ethyl-6-methyl-phenyl)-propionic acid (40.87 g) as pale brown crystals; 1H NMR (D6-DMSO): δ 1.17 (t, J=7.5 Hz, 3H), 2.30-2.39 (m, 5H), 2.67 (q, J=7.3 Hz, 2H), 2.87-2.94 (m, 2H), 7.47 (s, 2H), 12.30 (s, 1H).

1. extractionextracted with DCM (2×200 mL)
2. additionThe aqueous phase is added to 32% aq. HCl solution (50 mL) at 15-30° C
3. customThe solid material is collected
4. washwashed with water
5. customdried under high vacuum