Nitrogen → 5-Isoxazolemethanol, 3-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-, 5-acetate

Temperature

110 °C

To a 500 mL flask (under N2 (g)) was added dichlorobis(acetonitrile)palladium(II) (0.551 g, 2.12 mmol) and dicyclohexyl(2′,6′-dimethoxybiphenyl-2-yl)phosphine (3.50 g, 8.53 mmol). To the solids was sequentially added a solution of (4-bromo-3-methylisoxazol-5-yl)methyl acetate (24.8 g, 106 mmol) in 1,4-dioxane (65 mL), Et3N (44.3 mL, 318 mmol), and 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (24 mL, 160 mmol). The flask was sequentially evacuated and purged under N2 and this process was repeated three times. The reaction mixture was heated to 110° C. (under a constant stream of N2 (g)) and allowed to stir for ˜4 h. LC-MS analysis at this point showed complete conversion of the starting bromo-isoxazole. The reaction mixture was cooled to room temperature and EtOAc (100 mL) was added. After 15 min of stirring, the suspension was filtered over a pad of Celite. The filter cake was washed with EtOAc (3×100 mL), concentrated in vacuo, and the solvent was switched using 1,4-Dioxane (2×50 mL). The borate ester with used without further purification.

1. customThe flask was sequentially evacuated
2. custompurged under N2
3. temperatureThe reaction mixture was cooled to room temperature
4. additionEtOAc (100 mL) was added
5. stirringAfter 15 min of stirring
6. filtrationthe suspension was filtered over a pad of Celite
7. washThe filter cake was washed with EtOAc (3×100 mL)
8. concentrationconcentrated in vacuo
9. customThe borate ester with used without further purification

ORD record

ord-9d7963cb59c14d8aa85e297de7184521

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09249161B2