反应详情

温度

10 °C

To a 100 ml round bottomed flask was added 2,5-dichlorobenzoic acid (1.9 g, 10 mmol), 4-aminophenylacetic acid (1.5 g, 10 mmol), anhydrous sodium carbonate (3.2 g, 26 mmol), activated copper metal powder (0.25 g, 4 mmol) and 1-butanol (50 ml). The flask was fitted with a magnetic stirrer bar, water condenser, silica gel guard tube and heated under reflux for 48 hours. TLC (RPC18, Water, 20: methanol, 80) showed the formation of a slower moving component at Rf 0.55. The solvent was removed under reduced pressure with final drying under high vacuum. The residue was dissolved in 50 ml water and heated to boiling, then charcoal was added and the mixture filtered through celite, washing through with a further 25 ml of hot water. This solution was cooled to 10° C. in an ice bath and then acidified to pH≈2 with concentrated aqueous HCl. The oil that separated was extracted into chloroform, the solution dried with anhydrous magnesium sulphate, filtered and the solvent removed by rotary evaporation to leave a sticky solid. Recrystallization from water/acetic acid gave the title compound (1.07 g, 35%). δH (300 MHz, DMSO-d6) 3.54 (2H, s), 7.15-7.27 (5H, m), 7.39 (1H, dd) 7.81 (1H, d), 9.54 (1H, broad s) and 12.0-13.5 (2H, broad). Mass spectrum: (ES−) 304 (M−H). λmax (EtOH)=292, 364 nm.

1. customThe flask was fitted with a magnetic stirrer bar, water condenser, silica gel guard tube
2. temperatureheated
3. temperatureunder reflux for 48 hours
4. customThe solvent was removed under reduced pressure
5. customwith final drying under high vacuum
6. dissolutionThe residue was dissolved in 50 ml water
7. temperatureheated
8. additioncharcoal was added
9. filtrationthe mixture filtered through celite
10. washwashing through with a further 25 ml of hot water
11. customThe oil that separated
12. extractionwas extracted into chloroform
13. dry with materialthe solution dried with anhydrous magnesium sulphate
14. filtrationfiltered
15. customthe solvent removed by rotary evaporation
16. customto leave a sticky solid
17. customRecrystallization from water/acetic acid