Table 5.
Three-component synthesis of different 4H-chromene (8a–h) via condensation of various aldehydes (1), malononitrile (2) and dimedone (7) in the presence of Fe3O4@UiO@DAS.
| ||||||
|---|---|---|---|---|---|---|
| En | Aldehyde | Compound | Producta | Time (min) | Yieldb (%) | M.P (°C) Obsd |
| 1 | Benzaldehyde | 7 | 8a | 20 | 91 | 235–237 |
| 2 | 2-Chlorobenzaldehyde | 7 | 8b | 20 | 93 | 218–220 |
| 3 | 4-Methoxybenzaldehyde | 7 | 8c | 25 | 90 | 212–214 |
| 4 | 4-Methylbenzaldehyde | 7 | 8d | 25 | 90 | 196–198 |
| 5 | 2,4-Dichlorobenzaldehyde | 7 | 8e | 20 | 88 | 221–223 |
| 6 | Terphthaldehyde | 7 | 8f | 30 | 90 | 206–208 |
| 7 | 3-Nitrobenzaldehyde | 7 | 8g | 15 | 86 | 210–211 |
| 8 | 2-Nitrobenzaldehyde | 7 | 8h | 15 | 86 | 218–220 |
Reaction conditions: Aldehyde (1, 1 mmol), Malononitrile (2, 1.1 mmol), dimedone (7, 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.