ChemicalBook CAS DataBase List HDH-PHARMA 26173

HDH-PHARMA 26173 synthesis

6synthesis methods

Product Name:HDH-PHARMA 26173
CAS Number:871836-51-0
Molecular formula:C6H4ClN3
Molecular Weight:153.57

134031-24-6

871836-51-0

General procedure for the synthesis of 4-chloro-1H-pyrazolo[4,3-c]pyridine using 2,4-dichloronicotinaldehyde as starting material: intermediate 1 (1.7 g, 9.7 mmol) was dissolved in dimethoxyethane (12 ml) at room temperature, followed by addition of hydrazine monohydrate (1.2 ml, 38.6 mmol). The reaction mixture was stirred at 75°C overnight. Upon completion of the reaction, the mixture was concentrated to dryness and the resulting crude product was purified by fast chromatography using 20% to 100% ethyl acetate/petroleum ether gradient elution to afford the target product, 4-chloro-1H-pyrazolo[4,3-c]pyridine, as a white solid (0.82 g, 56% yield). The structure of the product was confirmed by 1H NMR (400 MHz, DMSO-d6): δ 7.60 (d, J = 6.9 Hz, 1H), 8.14 (d, J = 6.0 Hz, 1H), 8.32 (s, 1H); mass spectra (ES + APCI)+: m/z 154 [M + H]+.

134031-24-6
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$30.00/1g

871836-51-0
168 suppliers
$30.00/1g

Yield:871836-51-0 56%

Reaction Conditions:

with hydrazine hydrate in 1,2-dimethoxyethane at 20 - 75;

Steps:

Intermediate 24-Chlora-1 H-pyrazolo[4, 3-c]pyridineTo a solution of Intermediate 1 (1.7 g, 9.7 mmol) in dimethoxyethane (12 ml) at room temperature was added hydrazine monohydrate (1.2 ml, 38.6 mmol) and the resulting mixture was stirred at 75 °C overnight. The mixture was then concentrated to dryness and the crude residue was purified by flash chromatography, eluting with 20 to 100% ethyl acetate/petroleum ether gradient to give a white solid (0.82 g, 56%). ¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.60 (d, J=6.9 Hz, 1 H), 8.14 (d, J=6.0 Hz, 1 H), 8.32 (s, 1 H); m/z (ES+APCI)⁺: 154 [M + H]⁺.

References:

MEDICAL RESEARCH COUNCIL TECHNOLOGY;GENENTECH INC.;CHAN, Bryan;CHEN, Huifen;ESTRADA, Anthony;SHORE, Daniel;SWEENEY, Zachary;McIVER, Edward WO2012/38743, 2012, A1 Location in patent:Page/Page column 82

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153034-90-3 Synthesis