Table 2.

Synthesis of pyran derivatives via condensation of aromatic aldehydes, malononitrile and dimedone using [Ch][OH] as catalyst in water.

Entry	R1	Time (h)	Products	Yields (%) a	Mp (°C) Measured	Mp (°C) References
1	C6H5	1	2a	92	232–234	234–235 [57]
	4-NO2-C6H4	30 min	2b	88	176–177	177–178 [27]
2	3-NO2-C6H4	20 min	2c	95	213–214	213–215 [27]
3	4-Cl-C6H4	1	2d	86	212–214	209–210 [19]
4	4-F-C6H4	10 min	2e	90	198–200	200 [28]
5	4-Br-C6H4	1	2f	91	165–168	169–170[30]
6	4-CN-C6H4	30 min	2g	90	227–229	224–226 [18]
7	4-OH-C6H4	2	2h	86	206–298	207–209 [28]
8	4-MeO-C6H4	3	2i	95	198–200	199–200 [28]
9	4-N(Me)2-C6H4	5	2j	98	216–218	217–218 [57]
10	3,4-2(MeO)-C6H3	3	2k	92	184–185	182–184 [14]
11 c	3-Pyridine	10	2l	0	-	-
12	2-Furyl	3	2m	82	223–226	222–224 [57]
13 c	2-Naphthyl	10	2n	0	-	-
14	2-Thienyl	1	2o	85	210–212	210–212 [18]
15 b	C6H5-CH=CH-	5	2p	68	205–207	208–210 [27]
16 b	CH3CH2	3	2q	85	190–192	190–194 [22]
17 b	CH3CH2CH2	3	2r	79	192–194	192–193 [58]

^aIsolated yields;

^b20 Mol % amount of [Ch][OH] and reaction temperature of 100 °C were required;

^cOnly Knoevenagel condensation products were detected.