Table 2.
Effect of different amounts of catalysts, temperature and solvent (5 mL) in the triazole-dihydropyrano[3,2-b]pyran.
 
 | |||||
|---|---|---|---|---|---|
| Entry | Solvent | Conditions | Catalyst (mg) | Time (h) | Yield (%) | 
| 1 | H2O | r.t. | 10 | 4 | 10 | 
| 2 | t-BuOH | r.t. | 10 | 6 | Trace | 
| 3 | DMF | r.t. | 10 | 6 | 25 | 
| 4 | MeOH | r.t. | 10 | 4 | 65 | 
| 5 | t-BuOH: H2O (2:1) | r.t. | 10 | 6 | 45 | 
| 6 | H2O | r.t., US | 10 | 2 | 80 | 
| 7 | MeOH | r.t., US | 10 | 2.5 | 70 | 
| 8 | t-BuOH | r.t., US | 10 | 3 | 35 | 
| 9 | DMF | r.t., US | 10 | 1.5 | 50 | 
| 10 | H2O | 60, US | 10 | 1 | 93 | 
| 11 | H2O | 80, US | 10 | 1 | 93 | 
| 12 | H2O | 60, US | 5 | 1.5 | 75 | 
| 13 | H2O | 60, US | 15 | 1.5 | 93 | 
Significant values are in bold.