Imidazole → 4'-(6-((Tert-butyldimethylsilyl)oxy)hexyloxy)-4-biphenylcarboxylic acid

関与物質

反応手順

To a solution of 9 (12.0 g, 38.22 mmol) and tert-butyldimethylsilyl chloride (13.07 g, 86.68 mmol) in anhydrous N,N-dimethylformamide (80 mL) was quickly added imidazole (10.62 g, 155.96 mmol). After stirring under argon overnight, the reaction mixture was shaken with diethyl ether (100 mL) and water (300 mL). The ethereal layer was separated and washed with a saturated NaHCO3 solution before drying over anhydrous MgSO4. The crude product resulting from evaporation of the solvent was purified by flash column chromatography on silica gel with methylene chloride: hexanes (1:1) as the eluent to afford a compound with silyl-protected hydroxyl and carboxyl groups. The compound was dissolved in tetrahydrofuran:methanol (120 mL:60 mL) followed by stirring with a solution of 10% K2CO3 aqueous solution (60 mL) for 1 h. The volume of the solution was reduced to 25% via evaporation under reduced pressure. Brine (250 ml; 120 g NaCl in 500 mL H2O) was added to the slurry, and the pH was adjusted to 5.0 with 1 M aqueous solution of potassium hydrogen sulfate, KHSO4. The precipitate was collected by filtration and washed with water followed by drying under vacuum at 70° C. to yield 10 (16.3 g, 99%). 1H NMR spectral data (400 MHz, Acetone-d6): δ 0.03 (s, 6H, —Si(CH3)2), δ 0.86 (s, 9H, —SiCCH3), δ 1.30–1.60 (m, 6H, —CH2—), δ 1.74 (m, 2H, —CH2—), δ 3.59 (t, 2H, —CH2OAr), δ 4.01 (t, 2H, SiOCH2—), δ7.03 (d, 2H, aromatic rings), δ 7.66 (d, 2H, aromatic rings), δ 7.70 (d, 2H, aromatic rings), δ 7.97 (d, 2H, aromatic rings).

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