反应详情

5-Methylpyridin-2-amine (CAS 1603-41-4) (2.014 g, 18.6 mmol) was added in one portion to 2-hydroxy-3-methylbutanoic acid (CAS 4026-18-0) (2.0 g, 16.9 mmol), 2-(3H-[1,2,3]triazolo[4,5-b]pyridin-3-yl)-1,1,3,3-tetramethylisouronium hexafluorophosphate(V) (7.08 g, 18.6 mmol) and N-ethyl-N-isopropylpropan-2-amine (5.80 mL, 33.9 mmol) in DCM (40 mL). The resulting suspension was stirred at ambient temperature for 70 hours. The reaction mixture was concentrated, diluted with EtOAc (150 mL) and washed sequentially with water (150 mL) and saturated brine (75 mL). The organic layer was dried over MgSO4, filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 20 to 50% EtOAc in isohexane to afford 2-hydroxy-3-methyl-N-(5-methylpyridin-2-yl)butanamide (500 mg).

1. concentrationThe reaction mixture was concentrated
2. additiondiluted with EtOAc (150 mL)
3. washwashed sequentially with water (150 mL) and saturated brine (75 mL)
4. dry with materialThe organic layer was dried over MgSO4
5. filtrationfiltered
6. customevaporated
7. customto afford crude product
8. customThe crude product was purified by flash silica chromatography, elution gradient 20 to 50% EtOAc in isohexane