[()TD$FIG]
L. Zare, M. Nikpassand / Chinese Chemical Letters 22 (2011) 531–534
533
Scheme 2.
1
. Experimental
1 13
IR spectra were determined on a Shimadzo IR-470 spectrometer. H NMR and C NMR spectra were recorded on a
5
00 MHz Bruker DRX-500 in CDCl or DMSO-d as solvent and TMS as internal standard. Chemicals were
3
6
purchased from Merck and Fluka. Elemental analyses were done on a Carlo-Erba EA1110CNNO-S analyzer and
agreed with the calculated values. All solvents used were dried and distilled according to standard procedures.
A mixture of aldehyde (1 mmol or in the case of 3k–q 0.5 mmol of aldehyde is required), dimedone (1 mmol),
NH OAc (1 mmol) and 15 mol% of L-proline in 10 mL H O was refluxed for the required reaction times (2.5–3.5 h).
4
2
The progress of the reaction was monitored by TLC (EtOAc:petroleum ether 1:4). After completion of the reaction, the
mixture was filtered. The filtrate was reused. The product was recrystallized from ethanol to produce 1,4-
dihydropyridine derivatives 3a–q as pure crystalline products in 80–95% yields.
1
.1. 3,3,6,6-Tetramethyl-9-(2-nitrophenyl)-3,4,6,7,9,10-hexahydroacridine-1,8(2H,5H)-dione (3b)
ꢀ
1
1
Brown solid, mp 281–282 8C, IR (KBr, cm ); 3450, 3080, 2980, 1650, 1520, 1480, 1360, 1220, 1140. H NMR
CDCl , 500 MHz): d 0.96 (s, 6H), 1.06 (s, 6H), 2.23–2.46 (m, 8H), 5.80 (s, 1H), 7.21 (t, 1H, J = 6.99 Hz), 7.30–7.35
(
(
3
1
m, 1H), 7.41–7.48 (m, 2H). C NMR (CDCl , 125 MHz): d 27.8, 29.5, 32.9, 41.2, 51.1, 112.9, 124.5, 127.0, 132.5,
3
3
134.2, 141.2, 149.6, 149.8, 195.9. Anal. Calcd. for C H N O : C, 70.03; H, 6.63; N, 7.10. Found: C, 70.25; H, 6.48;
23 26 2 4
N, 7.02.
0
0
1.2. 9,9 -(2,2 -(1,4-Phenylenebis(methylene))bis(oxy)bis(2,1-phenylene))bis(3,3,6,6-tetramethyl-3,4,6,7,9,10-
hexa-hydroacridine-1,8(2H,5H)-dione) (3n)
ꢀ
1
1
Light yellow solid, IR (KBr, cm ): 3288, 3060, 2954, 1631, 1487, 1365, 1224. H NMR (CDCl /DMSO-d ,
3
6
5
2
1
00 MHz): d 0. 86 (s, 12H), 0.89 (s, 12H), 2.0–2.67 (m, 16H), 5.0 (s, 4H), 5.16 (s, 2H), 6.4 (t, 2H, J = 7.4 Hz), 6.85 (d,
1
H, J = 8.14 Hz), 7.02 (t, 2H, J = 7.4 Hz), 7.29 (d, 2H, J = 6.7 Hz), 7.58 (s, 4H). C NMR (CDCl /DMSO-d ,
3
3
6
25 MHz): d 27.6, 29.7, 32.6, 40.9, 51.4, 113.6, 114.3, 120.6, 127.8, 127.5, 129.5, 137.4, 148.4, 149.9, 158.3, 196.0.
Anal. Calcd. for C H N O : C, 77.75; H, 7.12; N, 3.52. Found: C, 77.85; H, 7.26; N, 3.36.
54 60 2 6
Acknowledgment
Financial support from the Research Council of Islamic Azad University-Rasht Branch is sincerely acknowledged.