Imidazole → 2-Chloroethyl 3-t-butyldimethylsilyloxybenzoate

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Reaction Steps

To a solution of 2-chloroethyl 3-hydroxybenzoate (4.0 g, 0.02 mol) and tert-butyldimethylsilyl chloride (4.5 g, 0.029 mol) in 5 mL of dry DMF was gradually added imidazole (92.7 g, 0.04 mol). The solution was then stirred overnight. TLC analysis (silica gel, 20% ethyl acetate/hexane) showed clean conversion to a new material. The solution was poured into a 25 mL of water and extracted with 3×25 mL of ether. The combined ether solutions were dried over anhydrous MgSO4. Evaporation of the solvent gave an oil which was chromatographed on silica using 10% ethyl acetate/hexane to give the product quantitatively as a colorless liquid: 1H NMR (CDCl3) δ0.218 (s, 6H), 0.994 (s, 9H), 3.81 (t, 2H, J=5.7 MHz), 4.56 (t, 2H, J=5.7 MHz), 7.05-7.65 (m, 4H); 13C NMR (CDCl3) δ-4.97, 17.66, 25.12, 41.06, 63.91, 120.61, 122.19, 124.60, 128.95, 130.53, 155.31, 165.35; MS m/e (rel intensity) 314 (14), 257 (9), 235 (9), 213 (100), 185(6) 149 (7), 135 (10), 120 (6), 93 (13), 83 (6), 69 (9), 55 (9); Exact mass: calcd 314.1104, found 314.1110. ##STR28##

Provenance & Evidence