ChemicalBook CAS DataBase List 5-bromo-3-iodo-1H-pyrazolo[3,4-b]pyridine

5-bromo-3-iodo-1H-pyrazolo[3,4-b]pyridine synthesis

5synthesis methods

Product Name:5-bromo-3-iodo-1H-pyrazolo[3,4-b]pyridine
CAS Number:875781-18-3
Molecular formula:C6H3BrIN3
Molecular Weight:323.92

875781-17-2 Synthesis

875781-17-2
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$7.00/250mg

5-bromo-3-iodo-1H-pyrazolo[3,4-b]pyridine

875781-18-3
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$16.00/100mg

Yield: 97%

Reaction Conditions:

Stage #1:5-bromo-7-azaindazole with iodine;potassium hydroxide in N,N-dimethyl-formamide for 3.5 h;
Stage #2: with iodine;sodium hydroxide in 1,4-dioxane at 40; for 23 h;

Steps:

5
5-bromo-3 -iodo- 1 H-pyrazolo [3 ,4-bipyridine ( IV-A-I); To a stirred solution of the bromo-diazaindole III- A-I (1 g, 5.05 mmol) in DMF (14 mL) was added crushed KOH pellets (1.06 g, 19.03 mmol) in one portion. After 11 min, I₂ (1.15 g, 4.54 mmol) was added and the mixture stirred vigorously for 3.5 h. The mixture was then partially concentrated in vacuo, diluted with EtOAc (40 mL): saturated NaHCO₃ solution (20 mL) and partitioned. The aqueous layer was extracted with EtOAc (2 x 20 mL). The combined organic layers were dried (MgSO₄), filtered and concentrated to afford a 1 :1 mixture of III-A-1 and IV-A-I (1.377 g). This mixture was re-dissolved in 1,4-dioxane (14 mL) and treated with solid NaOH (0.7 g). The mixture was stirred for 5 min at RT and I₂ (0.7 g) was added. The mixture was stirred at 40 ⁰C for 23 h, diluted with EtOAc (50 mL) and washed with saturated aqueous Na₂S₂O₃ solution (30 mL). The aqueous layer was extracted with EtOAc (2 x 30 mL) and the combined organic extracts were dried (MgSO₄), filtered and concentrated to afford azaindazole IV-A-I (1.585 g, 97%). ¹H NMR (400 MHz; CDCl₃) δ 7.94 (d, J2.1, IH), 8.55 (d, J2.1, IH), 10.85 (brs, NH).