Acetic Anhydride → (3-Amidino-pyrazolo[3,4-b]pyridin-1-yl)-acetic acid tert-butyl ester

Reaction equation

[C:1]([O:5][C:6](=[O:21])[CH2:7][N:8]1[C:12]2=[N:13][CH:14]=[CH:15][CH:16]=[C:11]2[C:10]([C:17](=[NH:20])[NH:18]O)=[N:9]1)([CH3:4])([CH3:3])[CH3:2].CC(OC(C)=O)=O>[Pd].CC(O)=O>[C:1]([O:5][C:6](=[O:21])[CH2:7][N:8]1[C:12]2=[N:13][CH:14]=[CH:15][CH:16]=[C:11]2[C:10]([C:17](=[NH:18])[NH2:20])=[N:9]1)([CH3:4])([CH3:2])[CH3:3]

Participants

Procedure

[3-(N-Hydroxycarbamimidoyl)-pyrazolo[3,4-b]pyridin-1-yl]acetic acid tert-butyl ester (6.17 g) in a 100 mL vial was charged with AcOH (45 mL) and Ac2O (4.3 mL). The resultant mixture was stirred at room temperature for 1 h at this time the initial suspension became a clear solution. To this solution was added Pd/C (10%, 900 mg) and stirred under 1 atm H2 balloon, and resultant mixture was stirred over night at room temperature. Filtration from celite washed with DCM/MeOH and evaporation gave (3-amidino-pyrazolo[3,4-b]pyridin-1-yl)-acetic acid tert-butyl ester which was used without further purification.