2-Aminopyridine → HCID 178522107, compound
Reaction equation
[OH:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[N:5]=[N:4][C:3]=1[C:12]([O:14]C)=O.[NH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][N:18]=1>>[OH:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[N:5]=[N:4][C:3]=1[C:12]([NH:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][N:18]=1)=[O:14]Participants
3
Conditions
- Temperature
- 150 °C
Procedure
4-Hydroxy-cinnoline-3-carboxylic acid, methyl ester (6 g), prepared accoring to J. Chem. Soc. 687 (1968), is reacted with 2-aminopyridine (16.6 g, stepwise added) in polyphosphoric acid (300 g:160 g of H3PO4 and 140 g of P2O5) under stirring at 150° C. for 10 hours. After cooling, dilution with ice water and neutralization with 35% NaOH, the precipitate is filtered and washed with water. Crystallization from dimethylformamide gives 4.9 g of 4-hydroxy-N-(2-pyridyl)-cinnoline-3-carboxamide, m.p. 341°-343° C.
Workup
- temperatureAfter cooling