Water → Methyl 3-benzyloxy-4-oxo-5,6,7,8-tetrahydro-4H-pyrazolo[1,5-a][1,4]diazepine-2-carboxylate

Participants

Reaction Steps

To a solution of dimethyl 1-(3-azidopropyl)-4-benzyloxy-1H-pyrazole-3,5-dicarboxylate (152 mg, 0.407 mmol) in THF (2 mL) were added triphenylphosphine (107 mg, 0.407 mmol) and water (37 μL, 2.036 mmol). The reaction was stirred at room temperature overnight, and the solvent was removed in vacuo. The residue was dissolved in toluene and heated to 110° C. overnight. 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 7.44-7.41 (m, 2H), 7.34-7.28 (m, 3H), 6.70 (br s, 1H), 5.29 (s, 2H), 4.46-4.42 (t, 2H), 3.96 (s, 3H), 3.06-3.00 (m, 2H), 2.20-2.13 (m, 2H); ES MS (M+1)=316.

Provenance & Evidence