反应详情

Lactic acid (74 mL of an 85% aqueous solution, 0.84 mol) and freshly distilled 2-chloroethanol (670 mL, 10.0 mol) were refluxed with 400 mL of toluene and 0.4 mL of conc. H2SO4 until one equivalent of H2O was collected in a Dean-Stark trap. The reaction mixture was cooled to room temperature, diluted with ethyl ether, and washed with a NaHCO3 /NaCl solution. The organic phase was dried with MgSO4, solvent was removed under reduced pressure, and the residue was distilled at 10 mm Hg. A fraction recovered at 95°-100° C./10 mm Hg was redistilled to give 2-chloroethyl lactate as a clear colorless liquid (76.7 g, 60%): b.p. 95° C./10 mm Hg; 1H NMR δ 1.46 (d, 3 H, J=6.9 Hz), δ 2.95 (bs, 1 H), δ 3.72 (t, 2 H, J=5.6 Hz), δ 4.35 (q, 1 H, J=6.9 Hz), δ 4.44 (m, 2 H); 13C NMR20.4, 41.2, 64.8, 66.8, 175.2 ppm; HRMS calcd for C4H5ClO3Tms (M--CH3) 209.0401, obsd 209.0392.

1. customwas collected in a Dean-Stark trap
2. additiondiluted with ethyl ether
3. washwashed with a NaHCO3 /NaCl solution
4. dry with materialThe organic phase was dried with MgSO4, solvent
5. customwas removed under reduced pressure
6. distillationthe residue was distilled at 10 mm Hg
7. customA fraction recovered at 95°-100° C./10 mm Hg
8. distillationwas redistilled