反应详情

A solution of 2-(2,2-dimethoxy-ethoxy)-ethanol (11 g, 0.073 mol) and triethylamine (12 mL, 0.088 mol) in dichloromethane (150 mL) was cooled to 0° C. and a solution of 2-bromo-2-methyl propionyl bromide (8.5 mL, 0.069 mol) in 50 mL of dichloromethane was added dropwise in ca. 30 min. After stirring overnight at room temperature the resulting suspension was filtered and the yellow solution was washed with saturated NaHCO3 aqueous solution (2×100 mL) and dried with MgSO4. After filtration the solvent was removed under reduced pressure and the yellow oily residue was purified by distillation (b.p. 70° C./0.02 mbar) to give 14.0 g (0.061 mol, yield: 89%) of product as a colourless oil. 1H NMR (400.03 MHz, CDCl3, 298 K) δ=1.94 (s, 6H, (CH3)2CBr), 3.39 (s, 6H, OCH3), 3.56 (d, J=5.3 Hz, 2H, CHCH2), 3.76 (t, J=4.8 Hz, CH2OCH2), 4.33 (t, J=4.8 Hz, 2H, CH2OCO), 4.50 (t, 1H, CH(OCH3)2. 13C{1H} NMR (100.59 MHz, CDCl3, 298 K) δ=30.90 (2C, C(CH3)2), 54.13 (2C, CH3O), 55.79 (1C, BrC(CH3)2), 65.24 (1C, CH2C(═O)), 69.21 (1C, CHCH2O), 71.18 (1C, OCH2CH2), 102.83 (1C, CH).

1. filtrationwas filtered
2. washthe yellow solution was washed with saturated NaHCO3 aqueous solution (2×100 mL)
3. dry with materialdried with MgSO4
4. filtrationAfter filtration the solvent
5. customwas removed under reduced pressure
6. distillationthe yellow oily residue was purified by distillation (b.p. 70° C./0.02 mbar)