Multicomponent reaction for the synthesis of tri-substituted 4H-pyrans and tetra-substituted pyranopyrazoles.

Entry	Aldehyde	Product	Time (min)	Yielda (%)	TON	TOF	Mp (°C)		Ref.
							Obtained	Reported
1	Benzaldehyde	1a	15	97	107.7	430	209–210	208–210	51
2	4-Chlorobenzaldehyde	1b	15	93	103.3	413.2	172	172–174	51
3	4-Bromobenzaldehyde	1c	10	92	102.2	638.8	178–179	178	52
4	4-Hydroxybenzaldehyde	1d	15	90	100	400	177	175–177	53
5	4-Methoxybenzaldehyde	1e	20	95	105.5	319.8	137	135–137	52
6	4-Methylbenzaldehyde	1f	20	85	94.4	286.2	174–176	175–177	51
7	4-Fluorobenzaldehyde	1g	10	94	104.4	652.7	274–276	274–277	51
8	4-Nitrobenzaldehyde	1h	15	88	97.7	391.1	182–183	180–183	54
9	3-Nitrobenzaldehyde	1i	15	83	92.2	368.8	190	189–191	55
10	2-Nitrobenzaldehyde	1j	15	90	100	400	181–182	181–183	56
11	2-Chlorobenzaldehyde	1k	10	95	105.5	659.7	194–195	193–195	55
12	2-Bromobenzaldehyde	1l	15	95	105.5	422.2	186	185–187	55
13	Benzaldehyde	2a	15	98	108.8	435.5	262–263	261–263	57
14	4-Chlorobenzaldehyde	2b	15	95	105.5	422.2	231–233	231	57
15	4-Bromobenzaldehyde	2c	15	90	100	400	172–174	172–174	58
16	4-Hydroxybenzaldehyde	2d	20	90	100	303	254–256	255–257	59
17	4-Methoxybenzaldehyde	2e	20	88	97.7	296.3	211–212	210–212	60
18	4-Methylbenzaldehyde	2f	25	88	97.7	234	213–215	212–215	61
19	4-Fluorobenzaldehyde	2g	15	90	100	400	239–241	240–242	62
20	4-Nitrobenzaldehyde	2h	20	95	105.5	319.8	247–249	246–248	60
21	3-Nitrobenzaldehyde	2i	20	92	102.2	309.7	194	192–194	60
22	2-Nitrobenzaldehyde	2j	20	95	105.5	319.8	216	216–218	57
23	2-Chlorobenzaldehyde	2k	20	85	94.4	286.2	241–243	240–242	60
24	2-Bromobenzaldehyde	2l	20	83	92.2	279.5	232–233	232–235	61

^aIsolated yield.