反应详情

At 0° C., to above THF solution of 1,4-dimethylpyrazole was added n-BuLi (2.5M in hexane, 58.5 mL, 146 mmole). The reaction solution was stirred for 2 hour at RT and then cooled to −78° C. [J. Heterocyclic Chem. 41, 931 (2004)]. To the reaction solution was added 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (27.2 g, 146 mmole). After 15 min at −78° C., the reaction was allowed to warm to 0° C. and stir for 3 h. The reaction was diluted with saturated NH4Cl solution and extracted with DCM. The organics were dried over Na2SO4 and concentrated under vacuum to afford the title compound as a brown solid (21 g, 78%) which was used directly without further purification: LC-MS: 141 (M−C6H12)+, 223 (M+H)+. 1H NMR (CDCl3): δ 7.28 (s, 1H), 4.03 (s, 3H), 2.22 (s, 3H), and 1.32 (s, 12H).

1. waitAfter 15 min at −78° C.
2. temperatureto warm to 0° C.
3. stirringstir for 3 h
4. extractionextracted with DCM
5. dry with materialThe organics were dried over Na2SO4
6. concentrationconcentrated under vacuum