10168
F. Al-Omran et al. / Tetrahedron 57 -2001) 10163±10170
collected by ®ltration and recrystallized from ethanol as
yellow crystals ,2.01 g, 83%); mp 322±3248C. ,Found: C,
69.00; H, 6.95; N, 17.26. C14H17N3O requires: C, 69.11; H,
7.04; N, 17.27%); nmax: 3446 ,NH), 2202 ,CN) and 1625
,ring CO); dH: 1.66±1.68 ,4H, m, 2CH2); 2.21±2.37 ,2H, m,
CH2); 2.50 ,6H, s, NMe2), 2.50±2.60 ,2H, m, CH2); 4.77
,1H, d, J14 Hz, vinylic-H), 7.87 ,1H, d, J14 Hz, vinylic-
H), 12.20 ,1H, br, NH); dC: 160.73 ,C-3), 150.75 ,C-1),
149.50 ,C-20), 122.75 ,C-10), 117.02 ,CN), 113.78 ,C-4),
112.45, 98.75, ,aromatic), 29.80 ,NMe2), 24.17, 22.15,
21.82, 19.27 ppm ,4CH2) carbons; MS ,EI); m/z243.1
,M1).
To the reaction mixture, malononitrile ,0.66 g, 0.01 mol)
was added and re¯uxed for 3 h. The solvent was evaporated
under reduced pressure. The solid product so formed, was
collected by ®ltration and recrystallized from ethanol as
brown red crystals ,2.13 g, 68%).
Method B: a mixture of compound 11 ,2.63 g, 0.01 mol) and
,0.66 g, 0.01 mol) malononitrile in ethanol ,30 mL), and
0.5 mL of piperidine was re¯uxed for 4 h and then allowed
to cool at room temperature. The solid product so formed,
was collected by ®ltration and recrystallized from ethanol as
brown red crystals ,2.21 g, 71%); mp .3508C; ,Found: C,
65.35; H, 5.72; N, 13.80; C17H17N3O3 requires: C, 65.59; H,
5.46; N, 13.50%); nmax: 3420, 3363 ,NH2), 2214 ,CN), 1720
,ester CO) and 1651 cm21 ,ring CO). dH: 1.24 ,3H, t, J
6 Hz, Me), 1.66±1.67 ,4H, m, 2CH2), 2.16±2.20 ,2H, m,
CH2); 2.22±2.56 ,2H, m, CH2); 4.17 ,2H, q, J6 Hz,
OCH2); 7.14 ,1H, d, J10 Hz, H-11); 7.89 ,1H, d, J
10 Hz, H-10) and 12.33 ppm ,2H, br, NH2). dC: 164.73
,ester CO), 160.77 ,C-8), 149.83, 148.61, 120.25, 118.03,
117.01, 116.31, 113.83, 110.93, ,aromatic and other carbon
atoms), 61.39 ,OCH2), 24.17, 23.28, 22.55 and 21.82
,4CH2) and 17.69 ppm ,Me); MS ,EI): m/z311.1 ,M1).
2.1.6. 1-[20--N,N-Dimethylaminoethenyl)]-5,6,7,8-tetra-
hydro-3-thioxoisoquinoline-4-carbonitrile 9b. Method A:
in a similar manner to that described earlier for compound
9a, compound 8b ,2.04 g, 0.01 mol) in DMF ,20 mL) and
DMF DMA ,1.33 g, 0.01 mol) gave compound 9b ,1.99 g,
77%).
Method B: a mixture of 2-acetylcyclohexanone 1 ,1.40 g,
0.01 mol) and DMF DMA ,1.33 g, 0.01 mol) was fused at
1808C for 15 min. The reaction mixture was dissolved in
ethanol ,20 mL) and cyanothioacetamide ,1.0 g, 0.01 mol)
with a few drops of piperidine were added and the mixture
was re¯uxed for 3 h. The solvent was evaporated under
reduced pressure. The solid product was collected by ®l-
tration and recrystallized from ethanol as brown crystals
,1.83 g, 71%); mp 322±3248C, ,Found: C, 64.75; H, 6.82;
N, 16.11. C14H17N3S requires: C, 64.84; H, 6.61; N,
16.21%); nmax: 3429 ,NH) and 2218 cm21 ,CN); dH:
1.53±1.85 ,4H, m, 2CH2); 2.17±2.41 ,2H, m, CH2); 2.50
,6H, s, NMe2), 2.51±2.62 ,2H, m, CH2); 5.96 ,1H, d, J
12 Hz, vinylic-H), 7.21 ,1H, d, J12 Hz, vinylic-H), and
13.76 ,1H, br, NH). dC: 174 ,C-3), 156.96 ,C-1), 152.81
,C-20), 122.30, 121.13, 117.43, 114.78, 113.60, ,aromatic
and other carbon atoms), 29.65 ,NMe2), 27.88, 24.60, 22.04
and 19.41 ppm ,4CH2).
2.1.9. 2,6-Di--m-nitrophenylmethylene)cyclohexanone
17. A mixture of 1 ,1.39 g, 0.01 mol) and m-nitrobenzalde-
hyde ,1.51 g, 0.01 mol) and sodium hydroxide ,0.20 g in
5 mL H2O) in ethanol ,30 mL) was stirred at room tempera-
ture for 2 h. The solid product was collected by ®ltration and
recrystallized from ethanol as yellow crystals ,2.83 g, 78%),
mp 140±1428C; ,Found: C, 65.90; H, 4.57; N, 7.75.
C20H16N2O5 requires: C, 65.93; H, 4.34; N, 7.69%). nmax
:
1664 cm21 ,ring CO), dH: 1.66±1.67 ,2H, m, CH2), 2.56±
2.58 ,4H, m, 2CH2), 7.66±8.27 ,10H, m, Ar-H and ylidene
CH); dC: 189.43 ,CO), 148.70, 139.18; 137.40, 135.77,
134.56, 130.95, 129.41 and 124.91 ,aromatic and other
carbon atoms), 27.31 ,2CH2) and 22.93 ppm ,CH2), MS
,EI): m/z364.1 ,M1).
2.1.7. Ethyl 1,2-dihydro-6--cyclohexan-1-on-2-yl)-2-oxo-
pyridine-3-carboxylate 11. A mixture of 1 ,1.40 g,
0.01 mol) and DMF DMA ,1.33 g, 0.01 mol) was fused at
1808C for 15 min then allowed to cool at room temperature.
The reaction mixture was treated with ethyl cyanoacetate
,1.13 g, 0.01 mol) and re¯uxed for 3 h. The solvent was
evaporated under reduced pressure. The solid product, so
formed was collected by ®ltration and recrystallized from
ethanol as yellow crystals ,2.15 g, 82%); mp 138±1408C;
,Found: C, 63.89; H, 6.73; N, 5.57. C14H17NO4 requires: C,
63.86; H, 6.51; N, 5.32%); nmax: 1700 ,ester CO), 1680 ,ring
CO) and 1644 cm21 ,amide CO); dH 1.24 ,3H, t, J6 Hz,
Me); 1.51±1.56 ,4H, m, 2CH2); 2.09±2.32 ,2H, m, CH2);
2.39±2.50 ,3H, m, cyclohexanone-H and CH2); 4.16 ,2H, q,
J6 Hz, OCH2); 6.72 ,1H, s, H-5); 7.99 ,1H, s, H-4) and
8.32 ppm ,1H, br, NH); MS: ,EI), m/z263.2.
2.2. General procedure for the synthesis of 20a±c
A mixture of 17 ,3.64 g, 0.01 mol) and malononitrile
,0.66 g, 0.01 mol) or ethyl cyanoacetate ,1.13 g, 0.01 mol)
or benzoylacetonitrile ,1.45 g, 0.01 mol) in ethanol ,20 mL)
and piperidine ,0.5 mL) was re¯uxed for 4 h. Then solvent
was evaporated under reduced pressure. The solid products
were collected by ®ltration and recrystallized from a
mixture of ethanol and DMF ,3:1) to afford 20a, 20b, and
20c, respectively.
2.2.1. 2-Amino-4H-4--m-nitrophenyl)-8--m-nitrophenyl-
methylene)-cyclohexa[b]-pyran-3-carbonitrile 20a. This
compound was obtained as yellow crystals ,3.26 g, 76%),
mp 233±2358C; ,Found: C, 63.93; H, 4.23; N, 12.98.
C23H18N4O5 requires: C, 64.18; H, 4.18; N, 13.00%). nmax
:
2.1.8. Ethyl 6-amino-5-cyano-8-oxocyclohexa[c]quino-
lizine-9-carboxylate 15. Method A: a mixture of 1
,1.40 g, 0.01 mol) and DMF DMA was fused at 1808C fo r
15 min, and then allowed to cool at room temperature. The
reaction mixture was dissolved in ethanol ,20 mL) and ethyl
cyanoacetate ,1.13 g, 0.01 mol) with few drops of piperi-
dine were added. The reaction mixture was re¯uxed for 4 h.
3440, 3330 ,NH2) and 2191 cm21 ,CN); dH: 1.66±1.67 ,2H,
m, CH2); 2.16±2.20 ,2H, m, CH2), 2.22±2.56 ,2H, m, CH2),
4.31 ,1H, s, H-4), 6.93 ,1H, s, ylidene-H), 7.09±7.74 ,8H,
m, Ar-H) and 8.08 ppm ,2H, br, NH2); dC: 160.85 ,C-2),
148.89, 148.59, 146.97, 141.62, 139.11, 136.13, 135.34,
133.24, 132.56, 131.27, 130.76, 124.22, 123.13, 122.34,
121.29, 121.08, 116.91, 117.18 ,aromatic and other carbon