[F:1][C:2]1([F:14])[O:6][C:5]2[CH:7]=[CH:8][CH:9]=[C:10]([B:11]([OH:13])[OH:12])[C:4]=2[O:3]1.[Li][CH:16](CC)C.C1CCCCC1.CI>C1COCC1>[F:14][C:2]1([F:1])[O:6][C:5]2[C:7]([CH3:16])=[CH:8][CH:9]=[C:10]([B:11]([OH:13])[OH:12])[C:4]=2[O:3]1
(2,2-difluoro-1,3-benzodioxol-4-yl)boronic acid (Intermediate 35, crude material) was dissolved in THF (20 mL) and the resulting solution cooled down to −78° C. sec-BuLi 1.4M solution in cyclohexane (17.4 ml, 24.36 mmol) was added dropwise and the reaction mixture was stirred for 1.5 hours at −78° C. Methyl iodide (4.6 ml, 73 mmol) was then added and the reaction mixture was stirred for 2 hours while the temperature was allowed to reach room temperature. The reaction was quenched by addition of an aqueous 2N solution of HCl and diluted with ethyl acetate. The organic layer was collected and then washed twice with brine, dried over Na2SO4 and evaporated to dryness. Crystallization from n-heptane afforded the title compound (150 mg) as white solid.
Loading…
