2,6-Diaminopyridine → 2-Amino-1,8-naphthyridine
Reaction equation
[N:1]1[C:6]([NH2:7])=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:8].CN(C)[CH:11]=[CH:12][CH:13]=O.C(=O)([O-])[O-].[Na+].[Na+]>>[N:1]1[C:6]2[C:5](=[CH:11][CH:12]=[CH:13][N:7]=2)[CH:4]=[CH:3][C:2]=1[NH2:8]Participants
4
Conditions
- Temperature
- 120 °C
Procedure
Pyridine-2,6-diamine (0.30 g, 2.8 mmol), 3-dimethylaminoacrolein (90%, 0.30 g, 2.8 mmol), and polyphosphoric acid (PPA) (2.7 mL) were combined and the reaction mixture was heated to 120° C. for 10 hours. Then, the reaction mixture was poured on ice water and neutralized with solid sodium carbonate. The resulting aqueous mixture was extracted three times with ethyl acetate and the combined organic extracts were washed with brine, concentrated, and purified by column chromatography (EtOAc/hexanes) to give [1,8]-naphthyridin-2-ylamine Yield 85 mg (21%). LCMS (ESI): calc. C8H7N3=145; obs. M+H=146.
Workup
- extractionThe resulting aqueous mixture was extracted three times with ethyl acetate
- washthe combined organic extracts were washed with brine
- concentrationconcentrated
- custompurified by column chromatography (EtOAc/hexanes)
Sources & evidence
- ORD record
- ord-0b5432f1144941d2bf319538751c2612
- Source dataset
- uspto-grants-2016_07
- Patent number
- US09394315B2
Reaction notes
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