ChemicalBook CAS DataBase List 5-FLUORO-2,3-DIHYDRO-(1H)-INDOLE

5-FLUORO-2,3-DIHYDRO-(1H)-INDOLE synthesis

5synthesis methods

Product Name:5-FLUORO-2,3-DIHYDRO-(1H)-INDOLE
CAS Number:94805-51-3
Molecular formula:C6H4N2O
Molecular Weight:120.11

42182-27-4

94805-51-3

General procedure for the synthesis of 2-oxo-1,2-dihydropyridine-4-carbonitrile from 2-amino-4-cyanopyridine: Sodium nitrite (NaNO2, 0.99 g, 14.3 mmol) was added in batches to a well-stirred 2-amino-4-cyanopyridine (0.96 g, 8.1 mmol) dissolved in concentrated sulfuric acid (H2SO4, 1.2 mL) and water (11 mL) in a premixed solution. During the reaction, the temperature of the reaction mixture was maintained between 0-5 °C and strictly controlled in the range of 5 ± 5 °C. With the release of nitrogen (N2), the originally clarified solution gradually became turbid. The mixture was slowly warmed to room temperature with stirring, followed by reflux heating in a water bath for 30 min and finally cooled to room temperature. The solid product formed was collected by filtration, washed with water (H2O) and dried under vacuum to afford the target product 2-oxo-1,2-dihydropyridine-4-carbonitrile (0.9 g, 92% yield) as a colorless solid. The structure of the product was confirmed by 1H NMR (DMSO-d6): δ 8.21 (d, 1H, J = 2.4 Hz), 7.61 (dd, 1H, J = 2.4, 9.6 Hz), 6.38 (d, 1H, J = 9.6 Hz), 3.3 (broad peak, 1H + 2H2O).

42182-27-4 Synthesis

42182-27-4
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$10.00/1g

94805-51-3
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$13.00/100mg

Yield: 92%

Reaction Conditions:

with sulfuric acid;sodium nitrite in water at 0; for 0.5 h;Reflux;

Steps:

32.C Step C: 2-Hydroxy-4-cyanopyridine:
NaN0₂ (0.99 g, 14.3 mmol) was added in small portions to a well stirred solution of the product of Step B (0.96 g, 8.1 mmol) in a premixed solution of concentrated H₂S0₄ (1 .2 ml) and H₂0 (1 1 .5 ml) while the temperature of the reaction mixture was kept at ) 0 - 5°C. The clear solution became heterogenous with evolution of N₂. The mixture was allowed to warm up to room temperature with stirring, than heated on the water bath (reflux) for 30 min and cooled to room temperature. The solid formed was filtered off, washed with H₂0 and dried in vacuo to give the title product (0.9 g, 92%) as colourless solid. ¹ H NMR (DMSO-d₆) 8.21 (d, 1 H, J = 2.4 Hz), 7.61 (dd, 1 H, 2.4, 9.6 Hz), 6.38 (d, 1 H, J = 9.6 Hz), 3.3 (broad s, 1 H + 2H₂0).

References:

AKAAL PHARMA PTY LTD;GROBELNY, Damian W;GILL, Gurmit S WO2014/63199, 2014, A1 Location in patent:Page/Page column 59

100-48-1 Synthesis