Phosphorus oxychloride → 3-Chloro-5-chloro-2-methylquinoxaline

HRID 216841Notes

Reaction equation

HRID 216841 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][CH:5]=[C:6]2[C:11]=1[N:10]=[C:9](O)[C:8]([CH3:13])=[N:7]2.P(Cl)(Cl)([Cl:16])=O>[NH4+].[OH-]>[Cl:16][C:9]1[C:8]([CH3:13])=[N:7][C:6]2[C:11]([N:10]=1)=[C:2]([Cl:1])[CH:3]=[CH:4][CH:5]=2

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178432149HCID 178432149, compound

Product 1

HCID 577078723-Chloro-5-chloro-2-methylquinoxaline

Reagents, catalysts & solvents 1

HCID 14923Ammonium HydroxideSolvent

Conditions

Temperature
100 °C

Procedure

A mixture of 8-chloro-3-methylquinoxalin-2-ol (1.0765 g, 5.5314 mmol) and phosphorous oxychloride (10.127 mL, 110.63 mmol) was stirred at 100° C. After 3 h, the mixture was cooled to room temperature. The mixture was poured into ice (˜100 mL) with stirring and neutralized with NH4OH (30 mL) and ice with stirring. The resulting precipitate was collected by filtration, rinsed with water (200 mL), and dried to give 3,5-dichloro-2-methylquinoxaline as a pink solid: 1H NMR (400 MHz, DMSO-d6) δ ppm 7.98-8.07 (2H, m), 7.84 (1H, dd, J=8.3, 7.7 Hz), 2.79 (3H, s); LC-MS (ESI) m/z 213.0 [M+H]+. The pink solid was carried on crude without purification for the next step.

Workup

  1. temperaturethe mixture was cooled to room temperature
  2. stirringwith stirring
  3. stirringwith stirring
  4. filtrationThe resulting precipitate was collected by filtration
  5. washrinsed with water (200 mL)
  6. customdried

Sources & evidence

ORD record
ord-5562c343268c4c33936ddee04343a52d
Source dataset
uspto-grants-2012_06
Patent number
US08193199B2

Reaction notes

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