Phosphorus pentachloride → Methyl 3-chloro-2-phenylquinoxaline-6-carboxylate

HRID 2205099Notes

Reaction equation

HRID 2205099 reaction equation
O=[C:2]1[NH:11][C:10]2[C:5](=[CH:6][CH:7]=[C:8]([C:12]([O:14][CH3:15])=[O:13])[CH:9]=2)[N:4]=[C:3]1[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.P(Cl)(Cl)(Cl)(Cl)[Cl:23]>CC#N>[Cl:23][C:2]1[C:3]([C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)=[N:4][C:5]2[C:10]([N:11]=1)=[CH:9][C:8]([C:12]([O:14][CH3:15])=[O:13])=[CH:7][CH:6]=2

Participants

4

Reactant 2

HCID 24819Phosphorus pentachlorideHCID 67041704Methyl 3-oxo-2-phenyl-3,4-dihydroquinoxaline-6-carboxylate

Product 1

HCID 77231183Methyl 3-chloro-2-phenylquinoxaline-6-carboxylateYield 56%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

Methyl 3-oxo-2-phenyl-3,4-dihydroquinoxaline-6-carboxylate (100 mg, 0.36 mmol, 1.00 equiv) and PCl5 (220 mg, 1.07 mmol, 3.00 equiv) in CH3CN (10 mL) was allowed to react, with stifling, for 5 hrs while the temperature was maintained at reflux in an oil bath. The reaction was then quenched by the addition of 50 mL of water, and the pH value of the solution was adjusted to 9 with saturated K2CO3. The resulting solution was extracted with 3×50 mL of ethyl acetate, the organic layers combined and dried over anhydrous sodium sulfate, and concentrated under vacuum, affording 60 mg (56%) of methyl 3-chloro-2-phenylquinoxaline-6-carboxylate as a yellow solid.

Workup

  1. customto react
  2. temperaturewas maintained
  3. temperatureat reflux in an oil bath
  4. customThe reaction was then quenched by the addition of 50 mL of water
  5. extractionThe resulting solution was extracted with 3×50 mL of ethyl acetate
  6. dry with materialdried over anhydrous sodium sulfate
  7. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-608c952061ff48ee93f95db9e79ca2bb
Source dataset
uspto-grants-2016_06
Patent number
US09370522B2

Reaction notes

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