反应详情

温度

50 °C

To a solution of methyl 5-(2-benzyloxy-ethoxy)-2-nitro-benzoate (8.26 g, 24.93 mmol) in methanol (200 ml) was added LiOH (1N, 80 ml), and the reaction mixture was heated to 50° C. for 2 h. The solvent was evaporated, water was added (100 ml), and the solution was cooled in an ice bath. 3N HCl was added slowly to pH=2.5. The aqueous layer was salted with NaCl and extracted with ethyl acetate (4×75 ml). The aqueous layer was reacidified and extracted with ethyl acetate (100 ml). The combined organic extracts were washed with brine (100 ml), dried over MgSO4, filtered and evaporated to give an oil that solidified upon standing. The solid was washed with ether (30 ml), filtered and air dried to give 5-(2-benzyloxy-ethoxy)-2-nitro-benzoic acid (5.99 g, 75%). 1H NMR (CDCl3) 7.96 (1H, d, J=9.0), 7.36-7.25 (5H, m), 7.17 (1H, d, J=2.7), 7.05 (1H, dd, J=9.0, 2.7), 4.62 (2H, s), 4.22 (2H, m), 3.84 (2H, m).

1. customThe solvent was evaporated
2. additionwater was added (100 ml)
3. temperaturethe solution was cooled in an ice bath
4. addition3N HCl was added slowly to pH=2.5
5. extractionextracted with ethyl acetate (4×75 ml)
6. extractionextracted with ethyl acetate (100 ml)
7. washThe combined organic extracts were washed with brine (100 ml)
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. customevaporated
11. customto give an oil that
12. washThe solid was washed with ether (30 ml)
13. filtrationfiltered
14. customair dried