Phosphorus oxychloride → Ethyl 3-chloropyridazine-4-carboxylate

HRID 2076825Notes

Reaction equation

HRID 2076825 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:7](=O)[NH:8][N:9]=[CH:10][CH:11]=1)=[O:5])[CH3:2].O=P(Cl)(Cl)[Cl:15]>>[CH2:1]([O:3][C:4]([C:6]1[CH:11]=[CH:10][N:9]=[N:8][C:7]=1[Cl:15])=[O:5])[CH3:2]

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 12376255Ethyl 3-hydroxypyridazine-4-carboxylate

Product 1

HCID 14542887Ethyl 3-chloropyridazine-4-carboxylate

Conditions

Temperature
100 °C

Procedure

A mixture of 3-oxo-2,3-dihydro-pyridazine-4-carboxylic acid ethyl ester (355 mg, 2.11 mmol) and POCl3 (6 ml) was heated to 100° C. for 1 h. The volatiles were then removed and the remaining residue was neutralized with sat. NaHCO3-solution. This mixture was extracted three times with Et2O and the combined extracts were dried (Na2SO4) and evaporated to obtain the crude title compound. The remaining brown solid (364 mg, 1.95 mmol, 92%) was used in the next reaction step without further purification. MS: m/e=187.1 [M+H+].

Workup

  1. customThe volatiles were then removed
  2. extractionThis mixture was extracted three times with Et2O
  3. dry with materialthe combined extracts were dried (Na2SO4)
  4. customevaporated

Sources & evidence

ORD record
ord-d808e1385b484337a713e8cbd1a57e8b
Source dataset
uspto-grants-2011_04
Patent number
US07928106B2

Reaction notes

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