Synthesis of pyrano[2,3-c]pyrazoles from different aldehydes using Bentonite@MgFe₂O₄ @PGSA/Cu^a.

Entry	Substrate	Product	Time (min)	Yieldb (%)	Melting point (°C)
					Measured	Literature
1			20	90	262–264	262–264 (ref. 42)
2			20	92	82–83	82–83 (ref. 42)
3			25	90	247–249	247–249 (ref. 43)
4			20	94	240–242	240–242 (ref. 43)
5			15	95	97–98	95–97 (ref. 43)
6			10	98	243–245	244–245 (ref. 43)
7			10	95	244–246	244–246 (ref. 43)
8			10	98	258–260	259–261 (ref. 43)
9			10	91	69–70	69–70 (ref. 42)
10			10	95	211–212	212–213 (ref. 42)
11			10	94	241–243	240–242 (ref. 42)
12			15	93	224–226	226–228 (ref. 43)
13			15	88	220–221	224–225 (ref. 43)

^aReaction conditions: benzaldehyde derivatives (1 mmol), ethyl acetoacetate (1 mmol), hydrazine hydrate (1 mmol), malononitrile (1 mmol); and Bentonite@MgFe₂O₄@PGSA/Cu (0.2 mol%) were stirred at room temperature.

^bIsolated yield.