N,N-Dimethylaniline → Ethyl 7-chloro-3mesityl-2,5-dimethylpyrazolo[1,5-a]pyrimidin-6-carboxylate
Reaction equation
CN(C)C1C=CC=CC=1.[C:10]1([CH3:35])[CH:15]=[C:14]([CH3:16])[CH:13]=[C:12]([CH3:17])[C:11]=1[C:18]1[C:19]([CH3:34])=[N:20][N:21]2[C:26](=O)[C:25]([C:28]([O:30][CH2:31][CH3:32])=[O:29])=[C:24]([CH3:33])[NH:23][C:22]=12.P(Cl)(Cl)([Cl:38])=O>>[Cl:38][C:26]1[N:21]2[N:20]=[C:19]([CH3:34])[C:18]([C:11]3[C:12]([CH3:17])=[CH:13][C:14]([CH3:16])=[CH:15][C:10]=3[CH3:35])=[C:22]2[N:23]=[C:24]([CH3:33])[C:25]=1[C:28]([O:30][CH2:31][CH3:32])=[O:29]Participants
4
Procedure
Five droplets of N,N-dimethylaniline was added to a solution of ethyl 3-mesityl-2,5-dimethyl-7-oxo-4,7-dihydropyrazolo[1,5-a]pyrimidin-6-carboxylate (3 g, 8.49 mmol) in phosphorus oxychloride (80 g), followed by heating under reflux for four hours. The reaction mixture was added to ice and stirred for a while. Then, the mixture was extracted with ethyl acetate, and the organic layer was washed with an aqueous saturated solution of sodium bicarbonate and brine, dried over anhydrous magnesium sulfate and evaporated. The residue was purified by silica gel column chromatography (15-30% ethyl acetate/hexane), to give the title compound (1.94 g).
Workup
- temperatureby heating
- temperatureunder reflux for four hours
- additionThe reaction mixture was added to ice
- extractionThen, the mixture was extracted with ethyl acetate
- washthe organic layer was washed with an aqueous saturated solution of sodium bicarbonate and brine
- dry with materialdried over anhydrous magnesium sulfate
- customevaporated
- customThe residue was purified by silica gel column chromatography (15-30% ethyl acetate/hexane)
Sources & evidence
- ORD record
- ord-0af5b7e307ff4bb4995ced1a8bb208b4
- Source dataset
- uspto-grants-2005_08
- Patent number
- US06927221B2
Reaction notes
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