ChemicalBook CAS DataBase List 6-QUINOXALINECARBOXYLIC ACID

6-QUINOXALINECARBOXYLIC ACID synthesis

7synthesis methods

Product Name:6-QUINOXALINECARBOXYLIC ACID
CAS Number:6925-00-4
Molecular formula:C9H6N2O2
Molecular Weight:174.16

131543-46-9

619-05-6

6925-00-4

Stage 1: The compound (CAS:131543-46-9) was reacted with 3,4-diaminobenzoic acid in a mixed solvent of ethanol and acetic acid with glyoxal at 75 °C. After completion of the reaction, the resulting suspension was cooled to 5 °C and filtered. The collected wet cake of 6-quinoxaline carboxylic acid was washed with cold ethanol and subsequently dried under vacuum at 50 °C.

23088-23-5
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6925-00-4
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Yield:6925-00-4 76.6%

Reaction Conditions:

Stage #1:methyl quinoxaline-6-carboxylate with sodium hydroxide in ethanol;water for 4 h;Heating / reflux;
Stage #2: with hydrogenchloride in ethanol;water; pH=4

Steps:

I.1
Preparation Example I-1. Quinoxaline-6-carboxylic acid To a solution of quinoxaline-6-carboxylic acid methyl ester (2084mg, 11.07mmol) in ethanol (25mL) was added an aqueous solution of 1 N sodium hydroxide (25mL), and the solution was stirred for 4 hours under reflux. 1 N Hydrochloric acid was added to the reaction mixture to adjust the pH to 4, then, the precipitated solid was collected by filtration, washed with water and isopropanol, then dried to obtain the title compound (1477mg, 8.479mmol, 76.6%) as a solid. ¹H-NMR Spectrum (DMSO-d₆) δ (ppm): 8.18 (1 H, d, J=8.4Hz), 8.29 (1H, dd, J=8.4, 1.2Hz), 8.61 (1 H, d, J=1.2Hz), 9.00-9.07 (2H, m).

References:

Eisai R&D Management Co., Ltd. EP1782811, 2007, A1 Location in patent:Page/Page column 59

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131543-46-9 Synthesis

131543-46-9
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619-05-6
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$18.00/5g

6925-00-4
173 suppliers
$23.00/1 g

References

141-43-5 Synthesis