Hydrochloric Acid → 4-Imidazo[1,2-a]pyridin-7-ylbenzaldehyde
Reaction equation
[CH2:1](OC(OCC)CBr)[CH3:2].Cl.[NH2:11][C:12]1[CH:17]=[C:16]([C:18]2[CH:25]=[CH:24][C:21]([CH:22]=[O:23])=[CH:20][CH:19]=2)[CH:15]=[CH:14][N:13]=1.C([O-])(O)=O.[Na+]>O.O1CCOCC1.CO>[N:11]1[CH:1]=[CH:2][N:13]2[CH:14]=[CH:15][C:16]([C:18]3[CH:25]=[CH:24][C:21]([CH:22]=[O:23])=[CH:20][CH:19]=3)=[CH:17][C:12]=12Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 3
Conditions
- Temperature
- 23 °C
Procedure
A mixture of bromoacetaldehyde diethyl acetal (0.49 mL, 23.3 mmol, 2.0 equiv) and concentrated HCl (0.05 mL, 0.4 equiv) in water (10 mL) was stirred at 23° C. for 2 h, then heated at 80° C. for 30 min. The mixture was allowed to cool to 23° C., and 4-(2-aminopyridin-4-yl)benzaldehyde (2-2, 323 mg, 1.63 mmol, 1 equiv) and NaHCO3 (324 mg, 3.91 mmol, 2.40 equiv) were added. The resulting mixture was then heated to 50° C. where MeOH (2 mL) and dioxane (3 mL) were added to increase solubility. The reaction mixture was stirred at 50° C. for 18 h, then concentrated. The residue was partitioned between EtOAc (200 mL) and brine (200 mL). The organic layer was concentrated to provide 4-imidazo[1,2-a]pyridin-7-ylbenzaldehyde (2-3) as a brown solid. LRMS m/z (M+H) Calcd: 223.2, found 223.0.
Workup
- temperatureheated at 80° C. for 30 min
- temperatureto cool to 23° C.
- additionwere added
- temperatureto increase solubility
- stirringThe reaction mixture was stirred at 50° C. for 18 h
- concentrationconcentrated
- customThe residue was partitioned between EtOAc (200 mL) and brine (200 mL)
- concentrationThe organic layer was concentrated
Sources & evidence
- ORD record
- ord-ff2ad2d321cd4c27be4e08cfe4feb923
- Source dataset
- uspto-grants-2006_10
- Patent number
- US07125888B2
Reaction notes
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