反应详情

A solution of 4-methoxy-3-(3-methoxy-propoxy)-benzoic acid methyl ester (140 g, 0.55 mol) and NaOH (1N, 825 mL, 0.825 mol) in MeOH (840 mL) is stirred at RT for 18 h. After completion, the solvent is removed under reduced pressure, and the residue is diluted with water (200 mL) and extracted twice with AcOEt (250 mL). The aqueous layer is acidified by addition of aqueous HCl (2N, 470 mL) and extracted 3 times with AcOEt (1 L). The combined organic extracts are washed with brine, dried over Na2SO4, filtered and concentrated. The crude material is purified by crystallization in AcOEt to give the title compound. MS (LC-MS): 239.1 [M−H]−; tR (HPLC, CC 70/4 Nucleosil 3 C18HD column, 20 to 100% CH3CN in H2O in 2, then 4 min with 100% CH3CN, CH3CN and H2O with 0.1% TFA, flow: 1.5 mL/min): 2.43 min.

1. customAfter completion, the solvent is removed under reduced pressure
2. additionthe residue is diluted with water (200 mL)
3. extractionextracted twice with AcOEt (250 mL)
4. additionThe aqueous layer is acidified by addition of aqueous HCl (2N, 470 mL)
5. extractionextracted 3 times with AcOEt (1 L)
6. washThe combined organic extracts are washed with brine
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated
10. customThe crude material is purified by crystallization in AcOEt