反应详情

A solution of 2-(o-tolylaminobenzoxazol-6-yl)acetic acid (1.0 g, Reference Example 4) in dimethylformamide (75 mL) was treated with O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (1.35 g), then with diisopropylethylamine (1.2 mL) and then with ethyl (R)-3-(4-aminophenyl)butanoate (0.74 g, Reference Example 1). The mixture was kept at room temperature for an hour and then evaporated to low bulk. The residue was partitioned between hydrochloric acid (1M) and dichloromethane. The organic phase was washed with aqueous bicarbonate solution (5%) then with water, then dried, and then evaporated. The residue was suspended in ethanol (about 50 mL). The mixture was treated with aqueous sodium hydroxide (about 5 mL, 1M), then refluxed for 2 hours, then evaporated. The residue was triturated with aqueous hydrochloric acid (1M) then filtered. The insoluble material was washed with water, and then dried to give the title compound (0.48 g) as a white powder. MS: accurate mass=444.1936 (calculated 444.1923 MH+). LC-MS: RT=3.19 minutes (100% by ELSD); MS (ES+), 444 (MH+).

1. waitThe mixture was kept at room temperature for an hour
2. customevaporated to low bulk
3. customThe residue was partitioned between hydrochloric acid (1M) and dichloromethane
4. washThe organic phase was washed with aqueous bicarbonate solution (5%)
5. dry with materialwith water, then dried
6. customevaporated
7. additionThe mixture was treated with aqueous sodium hydroxide (about 5 mL, 1M)
8. temperaturerefluxed for 2 hours
9. customevaporated
10. customThe residue was triturated with aqueous hydrochloric acid (1M)
11. filtrationthen filtered
12. washThe insoluble material was washed with water
13. customdried