Réaction #81038

Équation de réaction

2-chloroethyl 3-hydroxybenzoate

ethyl acetate hexane

tert-butyldimethylsilyl chloride

imidazole

→

2-Chloroethyl-3-(tert-butyldimethylsilyloxy)benzoate

Solvants

water

DMF

Conditions de réaction

Traitement

1. 1
   Extractionextracted with 3×25 mL of ether
2. 2
   SéchageThe combined ether solutions were dried over anhydrous MgSO4
3. 3
   AutreEvaporation of the solvent
4. 4
   Autregave an oil which
5. 5
   Autrewas chromatographed on silica using 10% ethyl acetate/hexane
6. 6
   Autreto give the product quantitatively as a colorless liquid

Mode opératoire

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) δ 0.218 (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 found 314.1110. ##STR29##

Source