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

Table 4

Yields of the reaction in different conditions.

Amount of catalyst; (% mol)	Reaction time; (min)/temperature (°C)	Yields (%)
0	7/80	46
1	7/80	52
2	7/80	63
3	7/80	80
4	7/80	75
5	7/80	73