反应详情

To a solution of 3-chloro-2-isopropoxy-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (Preparation 7, 297.6 g, 897.9 mmol) in acetic acid:water (2.2 L:1.0 L) at 0° C. was added peracetic acid (191 mL, 1.077 mol) and the reaction was allowed to warm gradually to room temperature. After 4 hours the reaction was complete and was quenched with 0.5 M solution of sodium thiosulfate (225 mL). The resulting dark solution was evaporated to dryness and the residue was passed through a plug of silica (flushed with neat heptane follow by a gradient up to 10% ethyl acetate:heptane) to remove base line boronate salts. The filtrate was evaporated in vacuo to give a pale yellow viscous oil before further flash column chromatography was performed (1.5 kg for 80 g of material) using 30% ethylacetate in heptane as eluent) to provide a pale yellow solid which was triturated with heptane, dried under suction to give the title compound as a white solid.

1. customwas quenched with 0.5 M solution of sodium thiosulfate (225 mL)
2. customThe resulting dark solution was evaporated to dryness
3. customflushed with neat heptane
4. customheptane) to remove base line boronate salts
5. customThe filtrate was evaporated in vacuo
6. customto give a pale yellow viscous oil before further flash column chromatography
7. customto provide a pale yellow solid which
8. customwas triturated with heptane
9. customdried under suction