Triethylamine → [(E)-(2-propan-2-ylpyrazolo[1,5-a]pyridin-3-yl)methylideneamino]urea
Reaction equation
[CH:1]([C:4]1[C:12]([CH:13]=O)=[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][N:6]2[N:5]=1)([CH3:3])[CH3:2].Cl.[NH2:16][NH:17][C:18]([NH2:20])=[O:19].C(N(CC)CC)C>CO>[CH:1]([C:4]1[C:12](/[CH:13]=[N:16]/[NH:17][C:18]([NH2:20])=[O:19])=[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][N:6]2[N:5]=1)([CH3:2])[CH3:3]Participants
5
Procedure
A mixture of 2-isopropylpyrazolo[1,5-a]pyridine-3-carbaldehyde (0.5 g, 1 equivalent), semicarbazide hydrochloride (0.35 g, 1.2 equivalents), and triethylamine (0.4 mL, 1.1 equivalent) in 5 mL of methanol was reflux for 30 minutes. The solution was concentrated and the crude solids produced were extracted with THF, and the mixture was filtered through a 1 inch thick layer of sodium sulfate on top of a thin pad of silica gel to remove the ammonium salt. The filtrate was concentrated and the solid deposited was recrystallized from THF and hexanes to give (E)-2-((2-isopropylpyrazolo[1,5-a]pyridin-3-yl)methylene)hydrazinecarboxamide (0.46 g, 70% yield) as a yellow solid. Compound 1074.
Workup
- temperaturewas reflux for 30 minutes
- concentrationThe solution was concentrated
- customthe crude solids produced
- extractionwere extracted with THF
- filtrationthe mixture was filtered through a 1 inch thick layer of sodium sulfate on top of a thin pad of silica gel
- customto remove the ammonium salt
- concentrationThe filtrate was concentrated
- customthe solid deposited was recrystallized from THF and hexanes
Sources & evidence
- ORD record
- ord-0d974e9e231c4025a2ecf542138268e1
- Source dataset
- uspto-grants-2009_09
- Patent number
- US07585875B2
Reaction notes
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