ChemicalBook CAS DataBase List 5-BROMO-1H-PYRAZO[3,4-B]PYRIDINE

5-BROMO-1H-PYRAZO[3,4-B]PYRIDINE synthesis

5synthesis methods

Product Name:5-BROMO-1H-PYRAZO[3,4-B]PYRIDINE
CAS Number:875781-17-2
Molecular formula:C6H4BrN3
Molecular Weight:198.02

5-Bromo-2-fluoropyridine-3-carboxaldehyde

875781-15-0

875781-17-2

The general procedure for the synthesis of 5-bromo-1H-pyrazolo[3,4-b]pyridine from 5-bromo-2-fluoro-3-formylpyridine was as follows: preparation of 5-bromo-1H-pyrazolo[3,4-b]pyridine (D-1-3). Compound D-1-2 (20 g, 0.1 mol) was mixed with an ethanol solution of anhydrous hydrazine (18 g, 0.56 mol) and heated to reflux overnight. The progress of the reaction was monitored by thin layer chromatography (TLC, unfolding agent was petroleum ether/ethyl acetate, 2:1, v/v) to confirm complete consumption of the raw material. Upon completion of the reaction, the reaction mixture was concentrated under vacuum to about 50 mL and subsequently poured into water (500 mL). The resulting mixture was filtered and the filter cake was washed sequentially with water (50mL x 3) and ether (20mL x 3). Finally, the filter cake was dried under vacuum to afford the target compound D-1-3 (9.0 g, 46% yield) as a yellow solid.

875781-15-0 Synthesis

875781-15-0
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$6.00/1g

875781-17-2
263 suppliers
$7.00/250mg

Yield:875781-17-2 46%

Reaction Conditions:

with hydrazine in ethanolHeating / reflux;

Steps:

D-1
Preparation of 5-bromo-1H-pyrazolo[3,4-b]pyridine (D-1-3). D-1-2 ^D"1-³A solution of compound D-1-2 (20 g, 0.1 mol) and anhydrous hydrazine (18 g, 0.56 mol) in ethanol was heated to reflux overnight. TLC (petroleum ether/EtOAc 2:1 ) indicated complete consumption of starting material. The reaction mixture was concentrated in vacuo to a volume of about 50 ml_ and poured into water (500 ml_), the resulting mixture was filtered. The cake was washed with water (50 ml_^χ3) and ether (20 ml_^χ3), then dried in vacuo to yield compound D-1-3 (9.0 g, 46%) as a yellow solid.

References:

PFIZER INC. WO2009/16460, 2009, A2 Location in patent:Page/Page column 99-100

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2065-75-0 Synthesis