Hydrochloric Acid → 5-Amino-2,1-benzoxaborol-1(3H)-ol

To a solution of 5-nitrobenzo[c][1,2]oxaborol-1(3H)-ol (CII) (360 mg, 2.01 mmol) in MeOH (25 mL) was added Zn dust (1.31 g, 20.11 mmol) and 2 M HCl (30 mL, 60.33 mmol). The reaction mixture was stirred at room temperature for 2.5 h before saturating with 5% aq. NaHCO3 (40 mL). The solids were filtered and filtrate was concentrated under reduce pressure to about 50 mL. The residue was diluted with EtOAc and the phases were separated. The organic layer was washed with brine, dried over MgSO4, and concentrated in vacuo to give 5-aminobenzo[c][1,2]oxaborol-1(3H)-ol (CIII) as a brown oil (250 mg, 1.68 mmol, 83% yield, 80% purity). ESIMS found for C7H8BNO2 m/z 149.9 (M+H). The crude product was used without further purification for coupling.

1. concentrationbefore saturating with 5% aq. NaHCO3 (40 mL)
2. filtrationThe solids were filtered
3. concentrationfiltrate was concentrated
4. additionThe residue was diluted with EtOAc
5. customthe phases were separated
6. washThe organic layer was washed with brine
7. dry with materialdried over MgSO4
8. concentrationconcentrated in vacuo

ORD-Eintrag

ord-ca8b7b2d4036495fbfda4a54d40dd04a

Quelldatensatz

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08933018B2