ChemicalBook CAS DataBase List 6-Bromo-1H-pyrazolo[4,3-b]pyridine

6-Bromo-1H-pyrazolo[4,3-b]pyridine synthesis

8synthesis methods

Product Name:6-Bromo-1H-pyrazolo[4,3-b]pyridine
CAS Number:1150617-54-1
Molecular formula:C6H4BrN3
Molecular Weight:198.02

6-Hydrazino-1H-pyrazolo[4,3-B]pyridine can be prepared by reacting 3,6-dichloro-2-pyridinecarboxaldehyde and hydrazine hydrate as raw materials.

669066-93-7 Synthesis

669066-93-7
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$58.00/50mg

1150617-54-1
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$15.00/100mg

Yield:1150617-54-1 275 mg

Reaction Conditions:

with hydrazine hydrate in ethylene glycol at 140; for 23 h;

Steps:

172.2 (2) Synthesis of 6-bromo-1H-pyrazolo[4,3-b]pyridine [172-2] (hereinafter referred to as a compound [172-2])

To a solution of the compound [172-1] obtained in the process (1) (426 mg) in ethylene glycol (2.1 mL) was added hydrazine monohydrate (197 μL) at room temperature, and then the reaction mixture was stirred at 140°C for 23 hours. After cooling to room temperature, to the reaction mixture was added water, and extracted with a mixed solution of chloroform/isopropanol (volume ratio 10/1). The obtained organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography to give the titled compound (275 mg) as a yellow solid. ¹H-NMR (400 MHz, CDCl₃) δ: 10.17 (1H, br), 8.65 (1H, d, J = 1.7 Hz), 8.31 (1H, s), 8.04 (1H, s). ESI-MS found: 198 [M+H]⁺

References:

EP2669270,2013,A1 Location in patent:Paragraph 0952-0953