Reaction equation
I[C:2]1[CH:3]=[N:4][NH:5][CH:6]=1.C([Li])CCC.[N:12]1[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=1[C:18](OCC)=[O:19]>O1CCCC1.CCCCCC.[Cl-].[NH4+]>[NH:4]1[CH:3]=[C:2]([C:18]([C:13]2[CH:14]=[CH:15][CH:16]=[CH:17][N:12]=2)=[O:19])[CH:6]=[N:5]1Participants
Procedure
To a solution of 4-iodopyrazole (1.0 g) in tetrahydrofuran (10 mL), a solution of n-butyllithium in hexane (2.6 M, 4.8 mL) was added dropwise at −10° C. and stirred at room temperature for 1 hour. The reaction mixture was cooled to −10° C. and ethyl picolinate (0.86 g) was added thereto, followed by stirring at room temperature for 1.5 hours. The reaction mixture was diluted with saturated aqueous ammonium chloride and extracted with diethyl ether. The organic layer was washed with brine, dried over sodium sulfate and concentrated under reduced pressure. The resulting residue was purified by NH-type silica gel column chromatography (eluting solvent: hexane:ethyl acetate=1:1 to 1:2) to give the titled compound (0.090 g) as a colorless solid.
Workup
- temperatureThe reaction mixture was cooled to −10° C.
- stirringby stirring at room temperature for 1.5 hours
- extractionextracted with diethyl ether
- washThe organic layer was washed with brine
- dry with materialdried over sodium sulfate
- concentrationconcentrated under reduced pressure
- customThe resulting residue was purified by NH-type silica gel column chromatography (eluting solvent: hexane:ethyl acetate=1:1 to 1:2)
Sources & evidence
- ORD record
- ord-10d50cd5288f4eca8dff9b9dfd123049
- Source dataset
- uspto-grants-2012_06
- Patent number
- US08193176B2
Linked notes
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