60 mmol) with vigorous stirring and external cooling by ice as
above. To this solution was added in one portion, diethyl 2,6-
dimethylpyridine-3,5-dicarboxylate 3 (2.51 g, 10 mmol) and
after one minute stirring the mixture was heated in an oil bath
at 80–85 ЊC for two days. Most of the excess of POCl3 was
removed in vacuo and then ice–water added followed by con-
centrated ammonium hydroxide, NH4PF6 or the appropriate
amine. Stirring precipitated a tan coloured solid. After ½ h
stirring the precipitate was filtered off, washed well with water,
recrystallised and dried in vacuo to give products as pale
yellow–brown crystals. Yields are collected in Table 2 and other
properties recorded below:
1,8-Dioxo-1,2,7,8-tetrahydro-2,7,10-triazaanthracene-4,5-di-
carbaldehyde (10). Pale brown crystals. Mp >300 ЊC; νmax KBr/
cmϪ1 3035, 2944, 2842, 1664, 1602, 1554, 1494, 1415, 1280,
1211, 1089; δH (270 MHz, DMSO-d6, 80 ЊC): 10.63 (s, 2H,
CHO), 9.88 (s, NH), 9.06 (s, 1H, H-9), 8.20 (s, 2H, H-3 and
H-6); δC (68 MHz, DMSO-d6, 80 ЊC): 187.4, 160.5, 153.6, 141.5,
136.9, 118.4, 112.9; m/z (electrospray): 270 (M ϩ 1, 100), 251
(8), 236 (13), 214 (12), 163 (55); m/z (CI): 269 (Mϩ, 5), 256 (7),
241 (10), 231 (28), 226 (18), 220 (68), 141 (39), 69 (34), 60 (100)
(Found: 269.0427; C13H7N3O4 requires 269.0436).
110.3, 60.7, 48.3; m/z (EI): 427 (Mϩ, 17), 386 (100), 347 (20),
331 (12), 319 (5), 281 (5), 56 (12) (Found: 427.2003; C25H25N5O2
requires 427.2008).
1,8-Dioxo-2,7-dibenzyl-4,5-bis(benzyliminomethyl)-1,2,7,8-
tetrahydro-2,7,10-triazaanthracene (13e). Yellow crystals, mp
199 ЊC (from acetonitrile); Found: C, 78.3; H, 5.2; N, 11.0.
C41H33N5O2 requires C, 78.45; H, 5.30; N, 11.16%); νmax KBr/
cmϪ1 3054, 3035, 2953, 1672, 1642, 1600, 1581, 1466, 1432,
1364, 1346, 1325, 1255; δH (270 MHz, DMSO-d6, 90 ЊC): 9.37
(s, 1H, H-9), 9.11 (s, 2H, CH᎐N), 8.45 (s, 2H, H-3 and H-6),
᎐
7.33–7.20 (m, 20H, Ph), 5.32 (s, 4H, CH N᎐), 4.81 (s, 4H,
᎐
2
CH2N–); δC (68 MHz, DMSO-d6, 90 ЊC): 160.7, 155.1, 153.2,
139.1, 138.4, 137.9, 136.3, 128.3, 128.2, 127.8, 127.6, 127.3,
126.3 (overlapping signals), 118.4, 112.6, 63.5, 51.0; m/z
(electrospray): 628 (Mϩ, 2), 539 (74), 450 (5), 225 (22), 91 (base
peak).
1,8-Dioxo-2,7-bis(4-methoxybenzyl)-4,5-bis[(4-methoxy-
benzyl)iminomethyl]-1,2,7,8-tetrahydro-2,7,10-triazaanthracene
(13f). Yellow crystals, mp 214–215 ЊC (from acetonitrile)
(Found: C, 72.1; H, 5.3; N, 9.4. C45H41N5O6 requires C, 72.27;
H, 5.53; N, 9.36%); νmax KBr/cmϪ1 3035, 2998, 2960, 2935, 2834,
1676, 1639, 1608, 1582, 1511, 1462, 1301, 1251, 1175, 1029, 823;
δH (270 MHz, DMSO-d6, 70 ЊC): 9.31 (s, 1H, H-9), 9.03 (s, 2H,
Hexafluorophosphate Salt 11. Pale brown crystals. Mp <300
ЊC (Found: C, 39.1; H, 5.2; N, 9.1. C25H39N5O4P2F12 requires C,
39.33; H, 5.15; N, 9.17%); νmax KBr/cmϪ1 1724, 1600, 1420,
1403, 1294, 1256; δH (270 MHz, DMSO-d6, 80 ЊC): 9.20 (s, 1H,
CH᎐N), 8.51 (s, 2H, H-3 and H-6), 7.33 (d, 4H, J 8.6 Hz, Ar),
᎐
7.26 (d, 4H, J 8.6 Hz, Ar), 6.90 (d, 8H, J 8.6 Hz), 5.24 (s, 4H,
CH N᎐), 4.75 (s, 4H, CH N–), 3.71 (s, 9H, OCH ); δ (68 MHz,
᎐
2
2
3
C
H-4), 8.06 (s, 4H, CH᎐), 4.45 (q, 4H, J 7.3 Hz, CH ), 3.53 (s,
DMSO-d6, 70 ЊC): 160.8, 158.8, 154.8, 153.2, 138.3, 138.0,
131.1, 129.1, 129.0, 128.7, 128.4, 118.4, 113.9, 113.6, 112.6,
63.0, 54.9, 54.8, 50.4; m/z (electrospray): 748 (Mϩ, 4), 629 (50),
121 (base peak).
᎐
2
12H, CH3), 2.90 (s, 12H, CH3), 1.45 (t, 6H, J 7.3 Hz, CH3);
δC (68 MHz, DMSO-d6, 80 ЊC): 164.3, 163.2, 154.1, 140.4,
127.7, 101.8, 60.1, 48.3, 13.8.
1,8-Dioxo-2,7-dimethyl-4,5-bis(methyliminomethyl)-1,2,7,8-
tetrahydro-2,7,10-triazaanthracene (13a). Soft, pale yellow
needles, mp 247–248 ЊC (from acetonitrile); νmax KBr/cmϪ1
1671, 1641, 1608, 1586, 1454, 1353, 1328, 1286, 809; δH (270
(S,S,S,S)-1,8-Dioxo-2,7-bis(1-phenylethyl)-4,5-bis-
[(1-phenylethyl)iminomethyl]-1,2,7,8-tetrahydro-2,7,10-triaza-
anthracene (13g). Pale brown crystals, mp 183–184 ЊC; [α]2D3
=
ϩ28 (c 0.2 in CHCl3); νmax KBr/cmϪ1 3552, 3473, 3413, 2965,
1673, 1637, 1616, 1600, 1573, 1450, 1367, 1230, 698; δH (270
MHz, CDCl ): 9.55 (s, 1H, H-9), 9.06 (s, 2H, CH᎐N), 8.23 (s,
᎐
3
2H, H-3 and H-6), 3.68 (s, 6H, NMe), 3.58 (s, 6H, NMe); δC (68
MHz, CDCl3): 161.6, 156.2, 153.3, 138.6, 138.2, 118.6, 112.9,
47.9, 36.8; m/z (CI): 324 (M ϩ 1, 30), 311 (20), 299 (15), 285 (8),
272 (2), 85 (32), 60 (base peak) (Found: 323.1394; C17H17N5O2
requires 323.1382).
1,8-Dioxo-2,7-diethyl-4,5-bis(ethyliminomethyl)-1,2,7,8-tetra-
hydro-2,7,10-triazaanthracene (13b). Yellow crystals, mp
280 ЊC (from acetonitrile); νmax KBr/cmϪ1 1684, 1641, 1606,
1581, 1465, 1367, 1327, 1285, 1248, 810; δH (270 MHz, CDCl3):
MHz, DMSO-d ): 9.26 (s, 1H, H-9), 9.01 (s, 2H, CH᎐N), 8.23
᎐
6
(s, 2H, H-3 and H-6), 7.40–7.19 (m, 20 H, Ph), 6.17 (q, 2H, J 7.3
Hz, CH), 4.63 (q, 2H, J 6.6 Hz, CH), 1.72 (d, 6H, J 7.3 Hz,
CH3), 1.45 (d, 6H, J 6.6 Hz, CH3); δC (68 MHz, DMSO-d6):
160.8, 153.3, 153.1, 144.9, 140.0, 138.5, 135.1, 128.1–125.9
(overlapping 10 C), 118.7, 112.7, 68.1, 53.9, 24.6, 18.7; m/z (EI):
683 (Mϩ, 39), 578 (base peak), 474 (29), 370 (24), 266 (64), 105
(99) (Found: 683.3257; C45H41N5O2 requires 683.3260).
1,8-Dioxo-2,7-bis(2-hydroxyethyl)-4,5-bis(2-hydroxyethyl-
iminomethyl)-1,2,7,8-tetrahydro-2,7,10-triazaanthracene (13h).
Orange crystals, mp >300 ЊC (from acetonitrile) (Found: C,
59.0; H, 5.7; N, 15.9. C21H25N5O6 requires C, 58.86; H, 5.69; N,
15.80%); νmax KBr/cmϪ1 3392, 2927, 2863, 1668, 1635, 1604,
1580, 1466, 1355, 1335, 1060; δH (270 MHz, DMSO-d6, 100 ЊC):
9.66 (s, 1H, H-9), 9.14 (s, 2H, CH᎐N), 8.32 (s, 2H, H-3 and
᎐
H-6), 4.17 (q, 4H, J 7.3 Hz, CH2), 3.74 (q, 4H, J 7.2 Hz, CH2),
1.49–1.35 (m, 12H, CH3); δC (68 MHz, CDCl3): 161.4, 154.5,
153.8, 139.5, 137.8, 119.3, 113.6, 55.9, 45.1, 16.3, 14.5; m/z (CI):
380 (M ϩ 1,base peak), 366 (2), 353 (20), 341 (2), 325 (3)
(Found: 379.1999; C21H25N5O2 requires 379.2008).
9.23 (s, 1H, H-9), 9.05 (s, 2H, CH᎐N), 8.40 (s, 2H, H-3 and H-
᎐
1,8-Dioxo-2,7-dibutyl-4,5-bis(butyliminomethyl)-1,2,7,8-tetra-
hydro-2,7,10-triazaanthracene (13c). Pale yellow crystals, mp
119–120 ЊC (from acetonitrile); νmax KBr/cmϪ1 2956, 2931, 2885,
1680, 1641, 1611, 1582, 1464, 1364, 1334, 1278, 813; δH (270
6), 4.98 (t, 4H, J 5.5 Hz, CH2), 4.65 (t, 4H, J 5.5 Hz, CH2), 4.13
(t, 4H, J 5.5 Hz, CH2), 3.92 (t, 4H, J 5.5 Hz, CH2); δC (68 MHz,
DMSO-d6, 100 ЊC): 161.0, 155.5, 153.4, 140.2, 137.7, 118.2,
111.4, 63.6, 60.9, 58.6, 51.6; m/z (electrospray): 444 (M ϩ 1, 6),
401 (38), 79 (base peak).
MHz, DMSO-d ): 9.17 (s, 1H, H-9), 8.96 (s, 2H, CH᎐N), 8.31
᎐
6
(s, 2H, H-3 and H-6), 4.05 (t, 4H, J 6.9 Hz, CH2), 3.61 (t, 4H,
CH2), 1.73–1.60 (m, 8H, CH2), 0.96–0.91 (m, 12H, CH3); δC (68
MHz, DMSO-d6, 40 ЊC): 160.7, 154.2, 153.1, 138.5, 137.6,
118.2, 112.2, 60.4, 48.4, 32.2, 30.5, 19.7, 19.2, 13.5, 13.4; m/z
(electrospray): 492 (M ϩ 1, 18), 434 (6), 376 (9), 85 (base peak)
(Found: 491.3269; C29H41N5O2 requires 491.3260).
1,8-Dioxo-2,7-diallyl-4,5-bis(allyliminomethyl)-1,2,7,8-tetra-
hydro-2,7,10-triazaanthracene (13d). Pale yellow crystals, mp
182 ЊC (from acetonitrile); νmax KBr/cmϪ1 3075, 3058, 2981,
2923, 2883, 1700, 1673, 1643, 1602, 1581, 1465, 1361, 1319,
1269, 1220, 923, 809; δH (270 MHz, DMSO-d6, 100 ЊC): 9.29 (s,
Formation of bis-imines from dialdehydes – general procedure:
The corresponding DOTTAD (1 mmol) was suspended in ethyl
acetate (10 mL) and an amine (2.2 mmol) was added. The reac-
tion mixture was stirred under reflux for 4–24 hours. The yellow
precipitate formed was filtered off, washed and dried to yield a
bright yellow solid. Yields are collected in Table 3 and other
properties recorded below:
2,7-Dimethyl-1,8-dioxo-4,5-bis[phenyliminomethyl]-1,2,7,8-
tetrahydro-2,7,10-triazaanthracene (14a). Yellow crystals, mp
236 ЊC (from ethyl acetate) (Found: C, 72.4; H, 4.8; N, 15.5.
C27H21N5O2 requires C, 72.47; H, 4.73; N, 15.65%); νmax KBr/
cmϪ1 2925, 2852, 1678, 1630, 1606, 1584, 1462, 1353, 1315,
1H, H-9), 9.07 (s, 2H, CH᎐N), 8.35 (s, 2H, H-3 and H-6), 6.13–
᎐
5.98 (m, 4H, allyl), 5.31–5.13 (m, 4H, allyl), 4.75–4.71(m, 4H,
allyl), 4.29–4.27 (m, 4H, allyl); δC (68 MHz, DMSO-d6, 100 ЊC):
158.6, 153.4, 151.3, 136.5, 135.9, 134.7, 131.0, 116.3, 113.9,
O r g . B i o m o l . C h e m . , 2 0 0 3 , 1, 1 5 4 5 – 1 5 5 1
1549