Sodium hydride → Ethyl 6-cyanopyrazolo[1,5-a]pyrimidine-3-carboxylate
Reaction equation
[H-].[Na+].[CH2:3]([O:5][C:6]([C:8]1[C:9]([NH2:13])=[N:10][NH:11][CH:12]=1)=[O:7])[CH3:4].C[N:15](C)[CH:16]=[C:17]([CH:20]=O)[C:18]#N>O1CCCC1>[CH2:3]([O:5][C:6]([C:8]1[CH:12]=[N:11][N:10]2[CH:20]=[C:17]([C:16]#[N:15])[CH:18]=[N:13][C:9]=12)=[O:7])[CH3:4]Participants
Procedure
Sodium hydride (60% dispersion in mineral oil, 0.52 g, 13.0 mmol) was added, at 0° C., to a mixture of 3-amino-1H-pyrazole-4-carboxylic acid ethyl ester (0.9 g, 5.8 mmol) and 3-dimethylamino-2-formyl-acrylonitrile (0.72 g, 5.8 mmol) in anhydrous tetrahydrofuran (30 mL) and the reaction mixture was stirred overnight while warming up to room temperature. Ice-water was added and the resulting mixture was partitioned between water and ethyl acetate; the organic layer was separated and the aqueous layer was extracted 3 times with ethyl acetate. The combined organic extracts were washed with brine, dried over anhydrous sodium sulfate, filtered and evaporated. The yellow crude residue was purified twice on a silica gel plug (EtOAc/hexane) to afford 0.4 g (32% yield) of 6-cyano-pyrazolo[1,5-a]pyrimidine-3-carboxylic acid ethyl ester.
Workup
- customthe resulting mixture was partitioned between water and ethyl acetate
- customthe organic layer was separated
- extractionthe aqueous layer was extracted 3 times with ethyl acetate
- washThe combined organic extracts were washed with brine
- dry with materialdried over anhydrous sodium sulfate
- filtrationfiltered
- customevaporated
- customThe yellow crude residue was purified twice on a silica gel plug (EtOAc/hexane)
Sources & evidence
- ORD record
- ord-ed181700ea424ec7aeb8442cc413c494
- Source dataset
- uspto-grants-2016_02
- Patent number
- US09255110B2
Reaction notes
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