Sodium Hydroxide → HCID 178434440, compound

Temperature

100 °C

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+).

1. additionThe resulting black oil is poured
2. customonto crushed ice
3. extractionextracted with EtOAc (2×100 mL)
4. dry with materialdried (MgSO4)
5. customthe solvent removed in vacuo
6. customPurification of the crude material by silica gel flash column chromatography

ORD record

ord-26a46723dcf4467da1e731edd4f3e6ab

Source dataset

uspto-grants-1999_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05859007