Phosphorus oxychloride → Ethyl 8-chloro-1-methyl-2-oxo-1,2-dihydropyrido[3,2-d]pyridazine-3-carboxylate

HRID 1966385Notes

Reaction equation

HRID 1966385 reaction equation
[CH3:1][N:2]1[C:7]2[C:8](=O)[NH:9][N:10]=[CH:11][C:6]=2[CH:5]=[C:4]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[C:3]1=[O:18].P(Cl)(Cl)([Cl:21])=O>>[Cl:21][C:8]1[C:7]2[N:2]([CH3:1])[C:3](=[O:18])[C:4]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:5][C:6]=2[CH:11]=[N:10][N:9]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 66988436Ethyl 1-methyl-2,8-dioxo-1,2,7,8-tetrahydropyrido[2,3-d]pyridazine-3-carboxylate

Product 1

HCID 46930535Ethyl 8-chloro-1-methyl-2-oxo-1,2-dihydropyrido[3,2-d]pyridazine-3-carboxylate

Conditions

Temperature
110 °C

Procedure

In a RBF equipped with reflux condenser, ethyl 1-methyl-2,8-dioxo-1,2,7,8-tetrahydropyrido[2,3-d]pyridazine-3-carboxylate (1.65 g, 6.63 mmol) was treated with phosphorus oxychloride (8.00 mL, 85.8 mmol). The reaction mixture was stirred in an oil bath at 110° C. for 90 min, and then cooled to RT. The volatiles were removed in vacuo and the residue was treated with CH2Cl2 then concentrated in vacuo. The residue was treated with CH2Cl2/Et2O and the resulting suspended solid was collected by suction filtration and dried in vacuo to give ethyl 8-chloro-1-methyl-2-oxo-1,2-dihydropyrido[3,2-d]pyridazine-3-carboxylate as a green solid. MS (ESI, pos. ion) m/z: 268 (M+1).

Workup

  1. customIn a RBF equipped
  2. temperaturewith reflux condenser
  3. temperaturecooled to RT
  4. customThe volatiles were removed in vacuo
  5. additionthe residue was treated with CH2Cl2
  6. concentrationthen concentrated in vacuo
  7. additionThe residue was treated with CH2Cl2/Et2O
  8. filtrationwas collected by suction filtration
  9. customdried in vacuo

Sources & evidence

ORD record
ord-c64e120cb3ff4a55b8e5ea60235663da
Source dataset
uspto-grants-2013_04
Patent number
US08420649B2

Reaction notes

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