Hydrochloric Acid → 6-Chloro-4-ethoxy-pyridazine-3-carboxylic acid ethyl ester
Reaction equation
[O-:1][CH2:2][CH3:3].[Na+].[CH2:5]([O:7][C:8]([C:10]1[N:11]=[N:12][C:13]([Cl:17])=[CH:14][C:15]=1Cl)=[O:9])[CH3:6].Cl.C([O-])(O)=O.[Na+]>C1COCC1.CCOC(C)=O>[CH2:5]([O:7][C:8]([C:10]1[N:11]=[N:12][C:13]([Cl:17])=[CH:14][C:15]=1[O:1][CH2:2][CH3:3])=[O:9])[CH3:6]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 0 °C
Procedure
Sodium ethoxide (1.16 g, 17 mmol) is added to a stirred solution of 4,6-dichloropyridazine-3-carboxylic acid ethyl ester (3.73 g, 17 mmol) in THF (45 mL) cooled to 0° C. The reaction mixture is stirred at room temperature overnight and then poured into 1N HCl (20 mL). The resulting solution is then neutralized with saturated NaHCO3. EtOAc (20 mL) is added and the layers are separated. The aqueous layer is extracted twice with EtOAc (20 mL) and the combined extracts are washed with brine (25 mL), dried (Na2SO4), and evaporated. The residue is then purified by flash column chromatography (silica gel, eluted with 2:1 Hexane, EtOAc) to give the title product as a white solid. H1 NMR δ (CDCl3) 7.02 (s, 1H), 4.47 (q, 2H, J=7.2 Hz), 4.19 (q, 2H, J=7.2 Hz), 1.50 (t, 3H, J=7.2 Hz), 1.41 (t, 3H, J=7.2 Hz).
Workup
- customthe layers are separated
- extractionThe aqueous layer is extracted twice with EtOAc (20 mL)
- washthe combined extracts are washed with brine (25 mL)
- dry with materialdried (Na2SO4)
- customevaporated
- customThe residue is then purified by flash column chromatography (silica gel, eluted with 2:1 Hexane, EtOAc)
Sources & evidence
- ORD record
- ord-368648d478334543afe2f74ff5c032db
- Source dataset
- uspto-grants-2006_10
- Patent number
- US07122546B2
Reaction notes
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