Sodium Carbonate → 4-(3-Phenylpyrazolo[1,5-a]pyrimidin-6-yl)benzaldehyde

Participants

Reaction Steps

A deoxygenated solution of 6-bromo-3-phenylpyrazolo[1,5-a]pyrimidine (1-3, 2.00 g, 7.30 mmol, 1 equiv), 4-formylphenylboronic acid (1-4, 1.65 g, 11.0 mmol, 1.51 equiv), aqueous sodium carbonate solution (6.00 mL, 12.0 mmol, 1.64 equiv), and tetrakis(triphenylphosphine)palladium (0.420 g, 0.363 mmol, 0.0500 equiv) in dioxane (100 mL) was heated at reflux for 20 hours. The reaction mixture was partitioned between aqueous sodium bicarbonate solution (200 mL) and ethyl acetate (200 mL). The organic layer was dried over sodium sulfate and concentrated. The residue was suspended in methanol (100 mL) and filtered to give 4-(3-phenylpyrazolo[1,5-a]pyrimidin-6-yl)benzaldehyde (1-5) as a yellow solid. 1H NMR (400 MHz, CDCl3) δ10.11 (s, 1H), 8.93 (d, 1H, J=2.4 Hz), 8.87 (d, 1H, J=2.2 Hz), 8.51 (s, 1H), 8.07 (m, 2H), 7.81 (br d, 2H, J=7.8 Hz), 7.49 (br t, 2H, J=7.7 Hz), 7.32 (t, 1H, J=7.5 Hz).

Provenance & Evidence