反应详情

A stirred suspension of (5-chloro-2-methoxyphenyl)acetic acid (10 g, 0.05 mol), anhydrous K2CO3 (8.3 g, 0.06 mol) and dimethyl sulfate (7.6 g, 0.06 mol) in anhydrous CH3CN (60 mL) was heated to reflux under nitrogen for 2 hours. The reaction mixture was allowed to cool and the excess dimethyl sulfate was quenched with Et3N (1 mL) and then filtered. The filtrate was rotary evaporated and the residue was suspended in water and extracted with ether, washed with satd. NaHCO3, water, brine and then dried (Na2SO4). Filtration and evaporation of the ether gave a colorless oil which was distilled in vacuo to afford methyl (5-chloro-2-methoxyphenyl)acetate (10.1 g, 94%): bp 96°-98° C./0.5 torr; IR (film, cm-1) 1742, 1250, 1150, 1028; 1H NMR (300 MHz, CDCl3)δ 3.56 (2 H, s), 3.66 (3 H, s), 3.76 (3 H, s), 8.75 (16 H, d, J=8.6 Hz), 7.13 (1 H, d, J=2.5 Hz), 7.17 (1 H, dd, J=8.6 and 2.5 Hz); MS m/e 215 (MH+).

1. temperaturewas heated
2. temperatureto reflux under nitrogen for 2 hours
3. temperatureto cool
4. customthe excess dimethyl sulfate was quenched with Et3N (1 mL)
5. filtrationfiltered
6. customThe filtrate was rotary evaporated
7. extractionextracted with ether
8. washwashed with satd
9. dry with materialNaHCO3, water, brine and then dried (Na2SO4)
10. filtrationFiltration and evaporation of the ether
11. customgave a colorless oil which
12. distillationwas distilled in vacuo