反应详情

Silver sulfate (0.671 g, 2.15 mmol) and iodine (0.11 mL, 2.15 mmol) were added successively to a solution of methyl trans-3-(4-methoxyphenyl)cyclobutanecarboxylate (0.474 g, 2.15 mmol) in MeOH (10.8 mL) at 25° C. and the reaction was stirred vigorously for 4 h. After this time the reaction mixture was filtered through a plug of Celite®. The filtrate was diluted with EtOAc (50 mL), washed with water (2×10 mL), aq. Na2SO3 (2×10 mL), and brine (10 mL), dried (Na2SO4) and concentrated in vacuo to give the crude product. This was purified by flash chromatography (Biotage Horizon, 25M, Si, ˜20 mL/imin, 100% hexanes for 144 mL, gradient to 20% EtOAc in hexanes over 2394 mL) to afford methyl trans-3-(3-iodo-4-methoxyphenyl)cyclobutanecarboxylate, as a colorless oil. Rf=0.54 (20% EtOAc/hexanes). LCMS calc.=347.01. found=347.02 (M+H)+. 1H NMR (500 MHz, CHCl3): δ 7.58 (d, J=2.2 Hz, 1H); 7.08 (dd, J=8.4, 2.2 Hz, 1H); 6.69 (d, J=8.4 Hz, 1H); 3.76 (s, 3H); 3.67 (s, 3H); 3.65-3.54 (m, 1H); 3.07-3.00 (m, 1H); 2.61-2.55 (m, 2H); 2.32-2.25 (m, 2H).

1. filtrationAfter this time the reaction mixture was filtered through a plug of Celite®
2. additionThe filtrate was diluted with EtOAc (50 mL)
3. washwashed with water (2×10 mL), aq. Na2SO3 (2×10 mL), and brine (10 mL)
4. dry with materialdried (Na2SO4)
5. concentrationconcentrated in vacuo
6. customto give the crude product
7. customThis was purified by flash chromatography (Biotage Horizon, 25M, Si, ˜20 mL/imin, 100% hexanes for 144 mL, gradient to 20% EtOAc in hexanes over 2394 mL)