Iodine → Ethyl 2-(4,6-difluoro-1-hydroxy-1-indanyl)acetate

Beteiligte Stoffe

Reaktionsschritte

A mixture of 4,6-difluoro-1-indanone (12.6 g, 0.08 mol), ethyl bromoacetate (19.0 g, 0.11 mol, Aldrich), activated zinc powder (7.5 g, 0.11 mol, Aldrich; Org. Syn., Coll. Vol. 6, 290, 1988) and a few crystals of iodine in diethyl ether:toluene (1:1, 300 mL) was heated at 30°-35° C. under a nitrogen atmosphere for 24 h. A few more crystals of iodine were added, the temperature was adjusted to 40°-45° C., and the mixture was kept at that temperature for an additional 24 h. The reaction mixture was filtered and concentrated in vacuo. The residue was treated with a mixture of diethyl ether (450 mL), concentrated ammonium hydroxide (135 mL) and water (135 mL). The aqueous phase was separated and extracted with diethyl ether. The combined organic phase was washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated in vacuo to give 22.7 g of crude Ethyl 2-(4,6-difluoro-1- hydroxy-1-indanyl)acetate which was Chromatographed on silica gel with dichloromethane:hexanes (9:1) as eluent gave 12.7 g (66%) of a yellow oil; NMR (CDCl3): d 6.67-6.88 (m, 2H), 4.22 (q, 2H), 3.02 (m, 1H), 2.75 (2 m's, 3H), 2.31 (m, 2H), 1.28 (t, 3H).

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