ChemicalBook CAS DataBase List QUINOXALINE-6-CARBALDEHYDE

QUINOXALINE-6-CARBALDEHYDE synthesis

11synthesis methods

Product Name:QUINOXALINE-6-CARBALDEHYDE
CAS Number:130345-50-5
Molecular formula:C9H6N2O
Molecular Weight:158.16

258503-93-4

130345-50-5

The general procedure for the synthesis of quinoxaline-6-carbaldehyde from quinoxaline-6-carbonyl chloride is as follows: in an 11-liter three-neck flask under argon protection, quinoxaline-6-carbonyl chloride was dissolved in 600 mL of 1,2-dimethoxyethane (DME). An equimolar amount of lithium tri-tert-butoxyaluminum hydride (LiAlH(Ot-Bu)3) was slowly added to this solution over a period of 1.5 hours at -78 °C. The reaction was stirred continuously at -78 °C for 5 hours. Upon completion of the reaction, the reaction was quenched by careful addition of ice water, followed by dilution of the reaction mixture with ethyl acetate (AcOEt) and filtration through a diatomaceous earth pad. The organic and aqueous layers were separated and the organic phase was washed with saturated sodium bicarbonate (NaHCO3) solution. After evaporation of the solvent under reduced pressure, quinoxaline-6-carbaldehyde was obtained in 73% yield and the product was a pale yellow solid. High performance liquid chromatography (HPLC) analysis showed a retention time of 1.49 min. Liquid chromatography-mass spectrometry (LC-MS) analysis showed a retention time of 0.81 min at m/z of 159.37 [M+H]+ in ESI positive ion mode. Nuclear magnetic resonance hydrogen spectroscopy (1H NMR, CDCl3) data were as follows: δ 10.28 (s, 1H), 8.97 (s, 2H), 8.61 (s, 1H), 8.27 (q, J=6 Hz, 9 Hz, 2H).

6344-72-5 Synthesis

6344-72-5
144 suppliers
$8.00/100mg

130345-50-5
164 suppliers
$24.00/100mg

Yield:130345-50-5 91%

Reaction Conditions:

with selenium(IV) oxide in 1,4-dioxane at 200; for 3 h;Product distribution / selectivity;Microwave irradiation;

Steps:

1.b
b) Quinoxaline-6-carbaldehyde. A suspension of 6-methylquinoxaline (8.0 g; 0.055 mol.) and selenium dioxide (6.77 g; 0.061 mol.) in 1,4-dioxane (5.0 mL) was irradiated at 200° C. for 30 min. in a Biotage Initiator microwave synthesizer. The above procedure was repeated five further times and the combined, cooled reaction mixtures were dissolved in CH₂Cl₂, filtered through a plug of celite, and concentrated in vacuo. Purification via flash column chromatography (silica gel, 20-50% ethyl acetate in hexanes) followed by crystallization from CH₂Cl₂provided quinoxaline-6-carbaldehyde (40.0 g, 91%) as a white solid. ¹H NMR (400 MHz, CDCl₃) δ ppm 10.25 (s, 1H) 8.95 (s, 2H) 8.57 (d, J=1.3 Hz, 1H) 8.24 (dd, J=8.6, 1.5 Hz, 1H) 8.20 (d, J=8.6 Hz, 1H). MS(ES+) m/e 159 [M+H]⁺.

References:

Duffy, Kevin J.;Fitch, Duke M.;Norton, Beth A. US2007/179144, 2007, A1 Location in patent:Page/Page column 4

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258503-93-4
41 suppliers
$44.00/100mg

130345-50-5
164 suppliers
$24.00/100mg

References