Pyridine → 5-Chloro-3-phenyl-1,2,4-oxadiazole
Reaction equation
[C:1]1([C:7]2[NH:11][C:10](=O)[O:9][N:8]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.N1C=CC=CC=1.P(Cl)(Cl)([Cl:21])=O>>[Cl:21][C:10]1[O:9][N:8]=[C:7]([C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=2)[N:11]=1Participants
4
Conditions
- Temperature
- 100 °C
Procedure
To a mixed solution of 3-phenyl-1,2,4-oxadiazol-5(4H)-one (2.00 g, 12.3 mmol) in phosphorus oxychloride (36 g) was added pyridine (1.93 ml, 23.9 mmol), and the mixture was stirred at 100° C. for 6 hours. The solvent was distilled off under reduced pressure. The residue was poured to ice water and extracted with ethyl acetate. The extract was washed with water and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=2:1) to give 1.17 g (52.4%) of the desired product as a solid.
Workup
- distillationThe solvent was distilled off under reduced pressure
- additionThe residue was poured to ice water
- extractionextracted with ethyl acetate
- washThe extract was washed with water
- dry with materialdried over anhydrous magnesium sulfate
- distillationthe solvent was distilled off under reduced pressure
- customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=2:1)
Sources & evidence
- ORD record
- ord-0d55a181e9ee40a9a84e9dddedf58690
- Source dataset
- uspto-grants-2010_12
- Patent number
- US07851473B2
Reaction notes
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