From: A green protocol ball milling synthesis of dihydropyrano[2,3-c]pyrazole using nano-silica/aminoethylpiperazine as a metal-free catalyst
Entry
Conditions
Time (min)
Yield (%)
References
Temp. (℃), Solvent, Catalyst
1
Reflux, EtOH, NAPT
30
82
[46]
2
Reflux, EtOH, RuIII@CMC/Fe3O4
93
[42]
3
Reflux, EtOH, PS-DABCO
120
84
[43]
4
r. t., H2O, Piperidine
5–10
89
[47]
5
Reflux, EtOH, Et3N
15
72
[48]
6
r. t., no solvent, Nano-SiO2/AEP
95
This work