3,3-二甲氧基丙醛

反应条件: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirring suspension of 5.0 g (51.5 mmol) of 3-Amino-5-methyl pyrazole in 10.1 g (61.8 mmol, 1.2 equiv) of malonaldehyde dimethyl acetal is added approx. 8 g of polyphosphoric acid, and the resulting mixture is heated to 100° C. for 2 h. The resulting black oil is poured onto crushed ice and made basic by the addition of 3N NaOH, then extracted with EtOAc (2×100 mL). The organic layers were combined, dried (MgSO4), and the solvent removed in vacuo. Purification of the crude material by silica gel flash column chromatography using hexane/EtOAc 1/1 as eluent afforded 160 mg of 3-Methyl-1H-pyrazolo[3,4-b]pyridine as a white solid: 1H NMR (CDCl3, 400 MHz) δ8.57 (dd, 1H, J=1.1, 4.7), 8.04 (dd, 1H, J=1.1, 8.0), 7.12 (dd, 1H, J=4.7, 8.0), 2.60 (s, 3H); low resolution MS (FAB)m/e 134 (MH+). The resulting black oil is poured onto crushed ice extracted with EtOAc (2×100 mL) dried (MgSO4) the solvent removed in vacuo Purification of the crude material by silica gel flash column chromatography

反应条件: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirring suspension of 5.0 g (51.5 mmol) of 3-Amino-5-methyl pyrazole in 10.1 g (61.8 mmol, 1.2 equiv) of malonaldehyde dimethyl acetal is added approx. 8 g of polyphosphoric acid, and the resulting mixture is heated to 100° C. for 2 h. The resulting black oil is poured onto crushed ice and made basic by the addition of 3N NaOH, then extracted with EtOAc (2×100 mL). The organic layers were combined, dried (MgSO4), and the solvent removed in vacuo. Purification of the crude material by silica gel flash column chromatography using hexane/EtOAc 1/1 as eluent afforded 160 mg of 3-Methyl-1H-pyrazolo[3,4-b]pyridine as a white solid: 1H NMR (CDCl3, 400 MHz) δ8.57 (dd, 1H, J=1.1, 4.7), 8.04 (dd, 1H, J=1.1, 8.0), 7.12 (dd, 1H, J=4.7, 8.0), 2.60 (s, 3H); low resolution MS (FAB)m/e 134 (MH+). The resulting black oil is poured onto crushed ice extracted with EtOAc (2×100 mL) dried (MgSO4) the solvent removed in vacuo Purification of the crude material by silica gel flash column chromatography

反应条件: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a stirring suspension of 5.0 g (51.5 mmol) of 3-Amino-5-methyl pyrazole in 10.1 g (61.8 mmol, 1.2 equiv) of malonaldehyde dimethyl acetal is added approx. 8 g of polyphosphoric acid, and the resulting mixture is heated to 100° C. for 2 h. The resulting black oil is poured onto crushed ice and made basic by the addition of 3N NaOH, then extracted with EtOAc (2×100 mL). The organic layers were combined, dried (MgSO4), and the solvent removed in vacuo. Purification of the crude material by silica gel flash column chromatography using hexane/EtOAc 1/1 as eluent afforded 160 mg of 3-Methyl-1H-pyrazolo[3,4-b]pyridine as a white solid: 1H NMR (CDCl3, 400 MHz) δ8.57 (dd, 1H, J=1.1, 4.7), 8.04 (dd, 1H, J=1.1, 8.0), 7.12 (dd, 1H, J=4.7, 8.0), 2.60 (s, 3H); low resolution MS (FAB)m/e 134 (MH+). The resulting black oil is poured onto crushed ice extracted with EtOAc (2×100 mL) dried (MgSO4) the solvent removed in vacuo Purification of the crude material by silica gel flash column chromatography