Microwave-Assisted Synthesis of Spirofused Heterocycles Using Decatungstodivanadogermanic Heteropoly Acid as a Novel and Reusable Heterogeneous Catalyst under Solvent-Free Conditions

Table 6

Comparison of the results of the present work with those of the earlier works.

Catalyst	Conditions	Yield (%)	Time	Reference
NBS/AIBN	Solvent-free/80°C	72–74	4 h	[6]
AlCl3	Ethanol/Reflux	82–84	5 h	[7]
H6GeW10V2O40·22H2O	MWI/Solvent free	87–90	6-7 min	This work