Benzenepropanoic acid → 3-(4-Iodophenyl)propanoic acid

Beteiligte Stoffe

Reaktionsschritte

A mixture of H2SO4 (1.25 mL), water (12.5 mL) and AcOH (25 mL) in a 250 mL flask and 3-phenylpropanoic acid (3.00 g, 20.0 mmol), iodine (1.40 g, 5.5 mmol) and KIO3 (0.98 g, 4.6 mmol) was added. The reaction was heated to reflux and a solution of iodine (1.40 g, 5.5 mmol) in AcOH (25 mL) was added in portions of 5 mL as the colour of the reaction faded from purple to orange. After 3 hours when no further colour changes appeared the reaction was cooled to room temperature. before quenching with 1M NaHSO3. The reaction was added water and extracted with EtOAc. The organic phases were combined, washed with brine, dried over MgSO4 and concentrated under vacuum. The product (4.15 g, 75%), containing minor impurites of starting material and the ortho-iodinated product, was recrystallised from PE to provide 1.83 g (33%) of the pure and white crystalline product. Rf: 0.10 (EtOAc:hexanes, 1:4); 1HNMR (CDCl3) δ 7.62-7.59 (m, 2H), 6.97-6.95 (m, 2H), 2.92-2.87 (t, 2H, J=7.5 Hz), 2.68-2.63 (t, 2H, J=7.5 Hz); 13CNMR (CDCl3) δ 178.5, 139.7, 137.6, 130.4, 91.6, 35.2, 30.0.

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