反应详情

Ethyl 3-(5-bromofuran-2-yl)-4-cyano-7-hydroxyisoxazolo[4,5-c]pyridine-6-carboxylate (42 mg, 0.11 mmol) and glycine (334 mg, 4.44 mmol) were added to sodium methoxide solution (6.7 mL, 3.33 mmol, 0.5 M in MeOH) and the mixture was refluxed for 48 h. The mixture was cooled to room temperature and the solvent was removed in vacuo. The residue was redissolved in a minimum amount of water, and 0.25 M hydrochloric acid was added until pH was 3. The resulting precipitate was isolated by filtration and dried under vacuum to give 21 mg of crude solid. The solid was dissolved in 10 mL of saturated sodium bicarbonate solution and washed with hexanes and EtOAc. The aqueous layer was acidified to pH 3 and extracted with EtOAc. The combined organic layer was dried over MgSO4 and concentrated to afford 10 mg of the title compound. MS: (−) m/z 405.21, 407.18 (M−1, 79Br/81Br).

1. temperaturethe mixture was refluxed for 48 h
2. customthe solvent was removed in vacuo
3. dissolutionThe residue was redissolved in a minimum amount of water, and 0.25 M hydrochloric acid
4. additionwas added until pH was 3
5. customThe resulting precipitate was isolated by filtration
6. customdried under vacuum
7. customto give 21 mg of crude solid
8. washwashed with hexanes and EtOAc
9. extractionextracted with EtOAc
10. dry with materialThe combined organic layer was dried over MgSO4
11. concentrationconcentrated