ChemicalBook CAS DataBase List 2-CHLORO-6-FLUOROQUINOXALINE

2-CHLORO-6-FLUOROQUINOXALINE synthesis

6synthesis methods

Product Name:2-CHLORO-6-FLUOROQUINOXALINE
CAS Number:55687-33-7
Molecular formula:C8H4ClFN2
Molecular Weight:182.58

145323-53-1 Synthesis

145323-53-1
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55687-23-5 Synthesis

55687-23-5
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1233932-59-6
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$71.00/100mg

55687-33-7
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$48.00/100mg

Yield:1233932-59-6 38%

Reaction Conditions:

in ethyl acetate;trichlorophosphate;

Steps:

2 Step 2:

A solution of 6-fluoroquinoxalin-2(1H)-one & 7-fluoroquinoxalin-2(1H)-one (3 g, 18.28 mmol) in POCl₃ (20 ml) was refluxed for 3 h.
The solvent was evaporated under reduced pressure and the residue was diluted with cold water.
The aqueous solution was basified by solid sodium carbonate and extracted with ethyl acetate.
The combine organic layer was dried over anhydrous sodium sulfate, filtered and evaporated under reduced pressure to get crude compound.
The crude compound was purified by silica gel chromatography (20% ethyl acetate in pet ether) to afford regioisomers as a mixture.
The above mixture was separated by SFC purification to afford 2-chloro-6-fluoroquinoxaline (0.75 g, 44%) and 2-chloro-7-fluoroquinoxaline (0.65 g, 38%) as white solid.
2-chloro-6-fluoroquinoxaline:
¹H NMR (400 MHz, DMSO-d6): δ ppm 8.75 (s, 1H), 8.14-8.11 (d, J=12 Hz, 1H), 7.67-7.64 (d, J=12 Hz, 1H), 7.59-7.54 (m, 1H); ¹⁹F NMR: δ ppm -107.15 (1F).

References:

US2013/115190,2013,A1 Location in patent:Page/Page column