To a solution of (4-bromo-2-cyclohexyloxyphenyl)acetic acid (1.33 g) inN,N-dimethylformamide (13 mL) were added K2CO3 (0.88 g)and iodomethane (1.33 g) at room temperature under nitrogen, and the mixturewas stirred at the same temperature for 2.5 d. The resulting mixture was pouredinto water and the aqueous layer was extracted with a mixture of hexane andethyl acetate (1:1). The organic layer was washed successively with water(twice) and brine, dried over anhydrous magnesium sulfate and evaporated underreduced pressure. The residue was purified by column chromatography on silicagel (hexane/toluene=1:1 to 1:2) to give ethyl(4-bromo-2-cyclohexyloxyphenyl)acetate (1.24 g)。
2-Hydroxy-1-naphthoic acid (470.5 mg, 2.5 mmol) in dry THF (2.5 mL)was treated with LiOH.H2O (104.9 g, 2.5 mol) at room temperature for30 min followed with Me2SO4 (0.24 mL, 2.5 mol), and themixture was heated for 3 h. Solvent was distilled off, and the mixture wasdiluted with saturated aqueous NaHCO3 and the extracted with Et2Oto afford the ester (485.16 mg, 96%) as a white solid .
Trethyl orthoacetate (16.0 mL, 87 mmol) was added dropwise to a solutionof 1-naphthoic acid (5.0 g, 29 mmol) in toluene (35 mL). The reaction mixturewas heated at reflux for 24 h. After the mixture has cooled, 2 N HCl (30 mL)was added. The organic extract was washed with saturated NaHCO3 (30mL) and brine (30 mL) and dried with MgSO4. The solvent was removedin cacuo to give a brown oil. Kugelrohr distillation of the product at 100℃ (0.45 Torr) gives the ethyl ester (5.15 g, 89%)
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