Research Article
Al(NO3)3 · 9H2O: An Efficient Catalyst for the One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Both under Reflux or Solvent-Free Conditions
Table 5
Biginelli synthesis of 5-ethoxycarbonyl-6-methyl-4-phenyl-3,4-dihydropyrimidin-2(1H)-one: Al(NO3)3·9H2O in comparison with some recent reports.
| | Entry | Conditions | Time (h:min) | Yield (%) |
| | 1 | Al(NO3)3·9H2O/SF, 80°C | 00:15 | 98 | | 2 | Sulfated tungstate/SF, 80°C [28] | 1:00 | 92 | | 3 | Silica gel-supported polyphosphoric acid (PPA-SiO2)/CH3CN, reflux [29] | 1:00 | 88 | | 4 | FeCl3 immobilized in Al-MCM 41/CH3CN, reflux [30] | 4:00 | 85 | | 5 | [Hmim]HSO4/solvent-free, 110°C [31] | 0:20 | 92 | | 6 | Alpha-zirconium sulfophenylphosphonate/SF, 80°C [32] | 18:00 | 89 | | 7 | 1,3-Dichloro-5,5-dimethylhydantoin/CH3CN, reflux [22] | 4:00 | 89 |
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