Phosphorus oxychloride → 5-Chloro-2-(2,4-difluorophenoxy)pyrido[3,2-d]pyridazine

HRID 1620410Notes

Reaction equation

HRID 1620410 reaction equation
[F:1][C:2]1[CH:19]=[C:18]([F:20])[CH:17]=[CH:16][C:3]=1[O:4][C:5]1[CH:6]=[CH:7][C:8]2[C:9](=O)[NH:10][N:11]=[CH:12][C:13]=2[N:14]=1.O=P(Cl)(Cl)[Cl:23]>>[Cl:23][C:9]1[C:8]2[CH:7]=[CH:6][C:5]([O:4][C:3]3[CH:16]=[CH:17][C:18]([F:20])=[CH:19][C:2]=3[F:1])=[N:14][C:13]=2[CH:12]=[N:11][N:10]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 674916092-(2,4-Difluorophenoxy)pyrido[3,2-d]pyridazin-5(6H)-one

Product 1

HCID 866645635-Chloro-2-(2,4-difluorophenoxy)pyrido[3,2-d]pyridazine

Conditions

Temperature
95 °C

Procedure

A mixture of 2-(2,4-difluorophenoxy)pyrido[3,2-d]pyridazin-5(6H)-one (1.00 g, 3.63 mmol) in POCl3 (8.00 mL, 85.82 mmol) was heated at 95° C. for 4 h. The excess POCl3 was removed under reduced pressure and the crude residue was treated with ice and 1N NaOH. The precipitated solid was filtered, rinsed with 2×5 mL of water followed by 2×5 mL of ether to provide 5-chloro-2-(2,4-difluorophenoxy)pyrido[3,2-d]pyridazine as a tan amorphous solid. MS (ESI, pos.ion) m/z: M+1=294.0

Workup

  1. customThe excess POCl3 was removed under reduced pressure
  2. additionthe crude residue was treated with ice and 1N NaOH
  3. filtrationThe precipitated solid was filtered
  4. washrinsed with 2×5 mL of water

Sources & evidence

ORD record
ord-dec81682069f4ddead3275e28a1d76e0
Source dataset
uspto-grants-2014_07
Patent number
US08772481B2

Reaction notes

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