4-Hydroxybenzaldehyde → HCID 136336149, compound

Participants

Reaction Conditions

Reaction Steps

2-[3,4-bis(methyloxy)phenyl]-3-oxopropanenitrile (100 mg, 0.49 mmol) was dissolved in ethanol (1 mL), and anhydrous hydrazine (98%, 19 μL, 0.52 mmol) was added. The resulting mixture was heated at reflux for 1 hour. It was cooled, concentrated, and the residue was dried in vacuum for one hour. To this residue was added of 4-hydroxybenzaldehyde (89 mg, 0.61 mmol) and trifluoroacetic acid (1 mL), and the mixture was heated at 70° C. for 18 hours. Then the reaction mixture was concentrated, dissolved in 10 mL of N,N-dimethylformamide and purified by preparatory HPLC (Shimadzu LC-8A HPLC, Waters Xterra C18 30 mm×100 mm column, acetonitrile-water-trifluoroacetic eluent). After concentration and lyophillization of the pure fractions 4-[7,8-bis(methyloxy)-3H-pyrazolo[3,4-c]isoquinolin-5-yl]phenol trifluoroacetic acid salt (60 mg, 0.15 mmol, 31% yield) was obtained. 1H NMR (400 MHz, d6-DMSO): 8.62 (s, 1H), 7.90 (s, 1H), 7.62-7.60 (d, 2H), 7.48 (s, 1H), 6.98-6.96 (d, 2H), 4.06 (s, 3H), 3.78 (s, 3H); MS (EI) for C18H15N3O3: 322 (MH+).

Provenance & Evidence