1,2,3,4-Tetrahydroisoquinoline → 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

Participants

Reaction Steps

To a solution of 3-benzyloxy-5-methyl-4-oxo-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine-2-carboxylic acid (60 mg, 0.199 mmol) in DMF (2 mL) under an atmosphere of nitrogen was added HATU (152 mg, 0.398 mmol) and 1,2,3,4-tetrahydroisoquinoline (32 mg, 0.239 mmol). The reaction was stirred at room temperature for 1 hour. Purification by reverse phase chromatography on a C-18 column using a gradient elution of 95-5% H2O (0.1% TFA)/CH3CN (0.1% TFA) and collection and concentration of the appropriate fractions afforded the title product. 1H NMR (400 MHz, CDCl3) δ 7.69-7.58 (m, 1H), 7.53-7.48 (m, 1H), 7.33-7.30 (m, 1H), 7.22-7.10 (m, 4H), 7.08-7.06 (d, 1H), 6.94-6.92 (d, 1H), 5.24-5.22 (d, 2H), 4.81 (s, 1H), 4.60 (s, 1H), 4.39-4.35 (t, 2H), 3.90-3.87 (m, 1H), 3.78-3.75 (t, 2H), 3.64-3.61 (t, 1H), 3.18 (s, 3H), 2.93-2.90 (t, 1H), 2.82-2.79 (t, 1H); ES MS (M+1)=417.

Provenance & Evidence