Research Article

Synthesis of Benzothiophene-Fused Pyran Derivatives via Piperidine Promoted Domino Reaction

Table 1

Optimization of .


EntrySolventTemp [°C]Time [min]Yield

DCM4020NR
2DCM401070
3CHCl3612068
4THF661571
5CH3CN841570
6EtOH801073
7Toluene1102057
EtOH801072
9EtOHr.t.1574
10DCMr.t.1583
11THFr.t.1063

conditions: 0.2 mol thioaurone 1a, 0.4 mol malononitrile 2a, 2.0 mL solvent at the corresponding temperature, and 10% mol piperidine as catalyst. yields. catalyst. acid as an additive.