Research Article
Multicomponent Reactions, Solvent-Free Synthesis of 2-Amino-4-aryl-6-substituted Pyridine-3,5-dicarbonitrile Derivatives, and Corrosion Inhibitors Evaluation
Table 1
Optimization of reaction conditions.
| Entry | Catalyst | | Aldehyde | Malononitrile | Amine | Yield (%) |
| 1 | ZnO | 1.5 | 1 | 2 | 1 | — | 2 | ZnO | 1.5 | 1 | 2 | 2 | — | 3 | ZnO | 1.5 | 1 | 2 | 3 | — | 4 | CAN | 1.5 | 1 | 2 | 1 | — | 5 | CAN | 1.5 | 1 | 2 | 2 | — | 6 | CAN | 1.5 | 1 | 2 | 3 | — | 7 | NaOEt | 1.5 | 1 | 2 | 1 | — | 8 | NaOEt | 1.5 | 1 | 2 | 2 | — | 9 | NaOEt | 1.5 | 1 | 2 | 3 | — | 10 | H3PO4 | 1.5 | 1 | 2 | 3 | — | 11 | H3PO4 | 1.5 | 1 | 2 | 3 | — | 12 | H3PO4 | 1.5 | 1 | 2 | 3 | — | 13 | AlCl3 | 1.5 | 1 | 2 | 1 | — | 14 | AlCl3 | 1.5 | 1 | 2 | 2 | — | 15 | AlCl3 | 1.5 | 1 | 2 | 3 | 25 | 16 | ZnCl2 | 1.5 | 1 | 2 | 1 | — | 17 | ZnCl2 | 1.5 | 1 | 2 | 2 | — | 18 | ZnCl2 | 1.5 | 1 | 2 | 3 | 45 | 19 | FeCl3 | 1.5 | 1 | 2 | 1 | — | 20 | FeCl3 | 1.5 | 1 | 2 | 2 | — | 21 | FeCl3 | 1.5 | 1 | 2 | 3 | 37 | 22 | Neat reaction | 0 | 1 | 2 | 1 | 90 |
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CAN = ceric ammonium nitrate.
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