反应详情

To a solution of 1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-6-carbaldehyde (370 mg, 1.95 mmol) in THF (15 mL) at rt was added NaBH(OAc)3 (827 mg, 3.9 mmol) followed by methylamine alcoholic solution (30%, 1.0 mL). Several drops of acetic acid were added to the reaction mixture to pH of 6. The mixture was continued to stir at rt overnight. Water (20 mL) was added and the mixture was extracted three times with ethyl acetate. The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by prep-HPLC to give 3,3-dimethyl-6-((methylamino)methyl)benzo[c][1,2]oxaborol-1(3H)-ol (300 mg; yield 75%) as a colorless oil. MS: m/z=206.1 (M+1, ESI+).

1. extractionthe mixture was extracted three times with ethyl acetate
2. washThe combined organic layers were washed with brine
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified by prep-HPLC