3-Benzyloxy-5-methyl-4-oxo-2-[(1,2,3,4-tetrahydro-isoquinolin-2-yl)carbonyl]-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine → 3-Hydroxy-5-methyl-4-oxo-2-[(1,2,3,4-tetrahydro-isoquinolin-2-yl)carbonyl]-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine

Participants

Reaction Steps

3-Benzyloxy-5-methyl-4-oxo-2-[(1,2,3,4-tetrahydro-isoquinolin-2-yl)carbonyl]-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine (46 mg, 0.110 mmol) was dissolved in a 30% solution of HBr in AcOH, and the reaction was stirred at room temperature for 30 minutes. The solvent was removed in vacuo, and purification of the product was achieved by reverse phase chromatography on a C-18 column using a gradient elution of 95-5% H2O (0.1% TFA)/CH3CN (0.1% TFA). Collection and concentration of the appropriate fractions afforded the title compound. 1H NMR (400 MHz, d6-DMSO) δ 9.88 (s, 1H), 7.24-7.13 (m, 4H), 5.19 (br s, 1H), 4.78 (br s, 1H), 4.37-4.34 (t, 2H), 4.20 (br s, 1H), 3.85 (br s, 1H), 3.76-3.73 (t, 2H), 2.98 (s, 3H), 2.90 (br s, 2H); ES MS (M+1)=327.

Provenance & Evidence