Hydrochloric Acid → 2,4-Bis(benzyloxy)-5-isopropenylbenzoic acid

関与物質

反応条件

反応手順

To a solution of 2,4-bis-benzyloxy-5-isopropenyl-benzoic acid benzyl ester (40.8 g, 87.9 mmol) in THF-MeOH-water (3:1:1, 300 mL total) was added lithium hydroxide (8.42 g, 352 mmol). The mixture was heated at 50° C. for 16 h, allowed to cool to ambient and then diluted with water (300 mL). The mixture was taken to pH˜1 using conc. HCl (−30 mL) and then extracted with EtOAc (2×200 mL). The combined organic extracts were washed with brine, dried (MgSO4), filtered and reduced in vacuo. The solid residue was taken up in P.E-MeOH (9:1, 300 mL total), the slurry stirred for 1 h at ambient and the solid collected by filtration. The solid was dried in vacuo to give the title compound (26.8 g) as an off-white solid. 1H NMR (400 MHz, DMSO-d6) 12.30 (s, 1H), 7.61 (s, 1H), 7.53 (d, J=7.0 Hz, 2H), 7.47-7.31 (m, 8H), 6.94 (s, 1H), 5.23 (d, J=14.0 Hz, 4H), 5.08 (d, J=9.0 Hz, 2H), 2.04 (s, 3H).

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