Table 3.
Three-component synthesis of different 2-amino-7-methyl-5-oxo-4-phenyl-4,5-dihydropyrano[4,3-b]pyran-3-carbonitrile (5a-i) via condensation of various aldehydes (1), malononitrile (2) and 4-hydroxy-6-methyl-2H-pyran-2-one (3) in the presence of Fe3O4@UiO@DAS.
| ||||||
|---|---|---|---|---|---|---|
| En | Aldehyde | Compound | Producta | Time (min) | Yieldb (%) | M.P (°C) |
| 1 | Benzaldehyde | 3 | 5a | 30 | 94 | 231–233 |
| 2 | 2-Chlorobenzaldehyde | 3 | 5b | 20 | 90 | 267–269 |
| 3 | 4-Chlorobenzaldehyde | 3 | 5c | 20 | 96 | 227–229 |
| 4 | 4-Nitrobenzaldehyde | 3 | 5d | 15 | 95 | 211–213 |
| 5 | 3-Nitrobenzaldehyde | 3 | 5e | 15 | 89 | 231–232 |
| 6 | Terephthaldehyde | 3 | 5f | 40 | 83 | 255–257 |
| 7 | 4-Methoxybenzaldehyde | 3 | 5g | 40 | 90 | 213–215 |
| 8 | 4-Ethoxybenzaldehyde | 3 | 5h | 40 | 90 | 202–204 |
| 9 | 3-Methylbenzaldehyde | 3 | 5i | 40 | 89 | 232–234 |
Reaction conditions: Aldehyde (1, 1 mmol), Malononitrile (2, 1.1 mmol), 4-hydroxy-6-methyl-2H-pyran-2-one (3) (1 mmol), and Fe3O4@UiO@DAS (13 mg) at reflux conditions.
aAll compounds are known and their structures were established from their melting points compared with authentic samples or literature values.
bIsolated yield