3,5-Dimethylisoxazole → HCID 57732079, compound
Reaction equation
[CH3:1][C:2]1[CH:6]=[C:5]([CH3:7])[O:4][N:3]=1.C([N-]C(C)C)(C)C.[Li+].[Cl:16][C:17]1[CH:18]=[C:19]([CH:22]=[CH:23][CH:24]=1)[CH:20]=[O:21]>C1COCC1>[Cl:16][C:17]1[CH:18]=[C:19]([CH:20]([OH:21])[CH2:7][C:5]2[O:4][N:3]=[C:2]([CH3:1])[CH:6]=2)[CH:22]=[CH:23][CH:24]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
To a solution of 3,5-dimethylisoxazole (104 g, 1.07 mol, 1 eq) in THF (1 L) cooled to −78° C. under nitrogen, a solution of lithiumdiisopropylamide (1.8 M ethylbenzene in THF) (630 mL, 1.134 mol, 1.06 eq) was added dropwise. After 1 hr, a solution of 3-chlorobenzaldehyde 100 g, 0.711 mole, 0.66 eq) in THF (300 mL) was added drop wise at −78° C. The reaction mixture was allowed to warm to room temperature and stirred overnight. It was cooled to 0° C., and quenched by saturated ammonium chloride solution (130 mL). The organic layer was concentrated to dryness. Water (1 L) was added to the residue was extracted with ethyl acetate (2×1 L). Combined organic extracts were washed with brine (700 mL) dried over anhydrous sodium sulfate. Concentrated and purified by column chromatography (50% ethyl acetate in hexane) over silica gel using a mixture of ethyl acetate and hexanes as eluant. The title compound was obtained as viscous brown oil (120 g, 0.507 mol, 48%).
Workup
- temperatureIt was cooled to 0° C.
- customquenched by saturated ammonium chloride solution (130 mL)
- concentrationThe organic layer was concentrated to dryness
- additionWater (1 L) was added to the residue
- extractionwas extracted with ethyl acetate (2×1 L)
- washCombined organic extracts were washed with brine (700 mL)
- dry with materialdried over anhydrous sodium sulfate
- concentrationConcentrated
- custompurified by column chromatography (50% ethyl acetate in hexane) over silica gel using
- additiona mixture of ethyl acetate and hexanes as eluant
Sources & evidence
- ORD record
- ord-1e38199313ba4029b46d23a7c3b39caf
- Source dataset
- uspto-grants-2014_06
- Patent number
- US08741934B2
Reaction notes
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