反应详情

3-Hydroxyisoxazole-5-carboxylic acid (396 mg, 307 μmol, 1.0 eq.), EDCI (54.4 μL, 307 μmol, 1.0 eq.) and HOBt (41.5 mg, 307 μmol, 1.0 eq.) were combined in DMF (0.2 mL) and stirred for 5 minutes at room temperature. (R)-4-Amino-5-biphenyl-4-yl-2,2-dimethyl-pentanoic acid ethyl ester (100 mg, 307 μmol, 1.0 eq.) was added and the resulting mixture was stirred for 30 minutes. 1 M LiOH in water (1.2 mL) in THF (3 mL) was added and the mixture was maintained at 60° C. for 2 days. A small amount of MeOH was added to speed up the reaction. The reaction was then quenched with AcOH and the product was purified by preparative HPLC to yield the title compound (25 mg, 95% purity. MS m/z [M+H]+ calc'd for C23H24N2O5, 409.17; Found 409.4.

1. stirringthe resulting mixture was stirred for 30 minutes
2. temperaturethe mixture was maintained at 60° C. for 2 days
3. customthe reaction
4. customThe reaction was then quenched with AcOH
5. customthe product was purified by preparative HPLC