10740
A. Rajca et al. / Tetrahedron 63 (2007) 10731–10742
treatment with ether, gave dialdehyde 5 (0.181 g, 37%). Mp
p-TsOH$H O (8.2 mg, 0.043 mmol) was evacuated in
2
ꢀ
1
2
9
3
3
1
1
7
17–220 C (under N ). H NMR (400 MHz, CDCl ): d
2
a Schlenk flask for 30 min. Subsequently, methanol
(0.5 mL) was added under N , and then the Schlenk vessel
3
.683 (s, 2H, CHO), 7.662 (s, 4H, ArH), 7.323 (s, 4H, ArH),
.927 (m, 8H, OCH ), 3.83–3.79 (m, 8H, OCH ), 3.622 (s,
2
ꢀ
was transferred to an oil bath at 55–60 C. The progress of
2
2
H, OCH ), 3.594 (s, 3H, OCH ), 3.595, 3.502 (AB, J¼
the reaction, for which it took between 2–3 days to complete,
was determined by TLC (silica, ether/hexanes); the di-con-
3
3
1
3
3 Hz, 8H, ArCH ). C NMR (100 MHz, CDCl ): d 191.8,
2
3
60.7, 154.4, 134.6, 133.7, 133.0, 132.5, 130.7, 115.2, 72.4,
2.3, 71.9, 71.9, 59.3, 59.0, 33.7. HR-FABMS (3-NBA
densation product had R z0 in acetone and in acetonitrile.
f
The crude was then washed with water (2ꢂ2 mL), ethanol
matrix) m/z (ion type, % RA for m/z¼868–875, deviation
containing a drop of Et N (1ꢂ1 mL), and ether (3ꢂ1 mL),
3
+
for the formula): 874.1553 ([M+2H+4] , 22%, 2.4 ppm
C42 H48 O10 Br ), 874.1553 ([M+H+5] , 22%,
2
to give bis(1,3-dihydroimidazolidine) 7 as a white solid
(0.115 g, 88%). From another reaction carried out on
0.153 g of the dialdehyde 5, bis(1,3-dihydroimidazolidine)
1
2
1
16
81
+
for
ꢁ
1
2
13
1
16
81
2.8 ppm for
C41 C H
1
O
Br ), 873.1507
2
47
10
12
+
1
16
81
1
(
[M+H+4] , 58%, ꢁ1.4 ppm for C42
H
47
12
O
10
13
Br2),
7 (0.165 g, 90%) was obtained. H NMR (600 MHz,
DMSO-d ): d 7.706 (s, 4H, OH, exch D O), 7.292 (s, 4H,
+
1
8
72.1516 ([M+H+3] , 57%, 3.7 ppm for C41 C H -
1
47
6
2
1
6
79
81
+
O1 Br Br ), 871.1508 ([M+H+2] , 100%, 0.9 ppm
1
ArH), 7.160 (s, 4H, ArH), 4.444 (s, 4H, CH), 3.818, 3.796
(AB, J¼16.2 Hz, 8H, ArCH ), 3.597 (t, J¼6.6 Hz, 8H,
0
1
1
1
2
16
79
81
+
for C42 H47
ꢁ
O
4.3 ppm for C41 C H
Br Br ), 871.1508 ([M+3] , 100%,
1
10
2
1
2
1
13
1
16
79
81
O10 Br1 Br ), 870.1483
1
OCH ), 3.329 (s, 6H, OCH ), 3.16–3.14 (br m, 4H, OCH ),
2
1
46
3
2
+
12
1
16
79
81
(
[M+2] , 57%, ꢁ5.2 ppm for C42 H46 O10 Br1 Br1),
3.085 (s, 6H, OCH ), 3.024 (t, J¼7.2 Hz, 4H, OCH ),
3
2
+
12
1
13
8
69.1514 ([M+H] , 54%, 2.5 ppm for
O10 Br ), 869.1514 ([M+1] , 54%, ꢁ2.6 ppm for
C42 H -
47
1.053 (s, 6H, CH ), 1.007 (s, 6H, CH ). C NMR
3 3
1
6
79
+
(150 MHz, DMSO-d ): 155.8, 155.0, 136.3, 135.9, 132.7,
6
2
1
1
2
13
16
46
16
79
10
79
+
C4 C H
O
for C42 H46 O10 Br ). IR (ZnSe, cm ): 2979, 2923,
Br ), 868.1445 ([M] , 17%, 1.4 ppm
131.5, 128.9, 113.7, 89.8, 71.3, 70.6, 69.7, 67.3, 66.0, 58.5,
58.3, 36.6, 24.6, 17.2. LR-FABMS (3-NBA matrix) m/z: cal-
1
1
1
2
2
1
ꢁ1
2
+
2
886, 1689, 1597, 1588, 1450, 1306, 1200, 1124, 1054, 1029.
culated for C H Br N O [M+H] 1132.0; found 1131.5.
75
5
4
2 4 12
ꢁ
1
IR (ZnSe, cm ): 3433, 3335, 2980, 2924, 1454, 1358, 1207,
1123, 1058, 1028, 845.
5
.9. Tetrakis(1,3-dihydroimidazolidine) 6: 5,11,17,23-
tetrakis(1,3-dihydroxy-4,4,5,5-tetramethylimidazolin-
-yl)-25,26,27,28-tetrakis(methoxyethoxy)calix[4]arene
2
5.11. Nitronyl nitroxide tetraradical 1: 5,11,17,23-tet-
rakis(1-oxyl-3-oxo-4,4,5,5-tetramethylimidazolin-2-yl)-
25,26,27,28-tetrakis(methoxyethoxy)calix[4]arene
A mixture of tetraaldehyde 4 (0.173 g, 0.224 mmol),
2
2
,3-bis(hydroxyamino)-2,3-dimethylbutane
(0.327 g,
.21 mmol), p-TsOH$H O (8.4 mg, 0.044 mmol) was evac-
Tetrakis(1,3-dihydroimidazolidine) 6 (0.225 g, 0.174 mmol)
was suspended in CH Cl (10 mL), and the suspension was
2
uated in a Schlenk flask for 30 min. Subsequently, methanol
(
2
2
ꢀ
a solution of NaIO (0.150 g, 0.696 mmol) in distilled water
1.0 mL) was added under N , and then the Schlenk flask
2
cooled to a temperature between ꢁ5 and 0 C. Subsequently,
ꢀ
was transferred to an oil bath at 60–65 C. The progress of
the reaction, it took between 2 and 2.5 days to complete,
was followed by TLC (silica, ether/hexanes); the tetra-con-
4
(15 mL) was added. The very light blue reaction mixture was
ꢀ
stirred at ꢁ5 to 0 C for 35 min, and then at room tempera-
densation product had R z0, even in acetone and in acetoni-
ture for an additional 30 min, resulting in a dark blue reac-
tion mixture. The completion of reaction was determined
by TLC (silica, ethyl acetate/acetone), as indicated by the
disappearance of starting material and the appearance of
a blue spot for tetraradical 1. The work up was carried out
by the addition of CH Cl (40 mL) and then washing of
f
trile. The crude was then washed with water (2ꢂ3 mL),
ethanol containing a drop of Et N (1ꢂ2 mL), and ether
3
(
a white solid (0.227 g, 79%). From two other reactions
3ꢂ1 mL) to give tetrakis(1,3-dihydroimidazolidine) 6 as
done on 51.0 mg of the tetraaldehyde 4 with methanol
(
2
2
ꢀ
hyde 4 with methanol (2 mL) and heating at 60–65 C, 6 was
2 mL) and heating at 65–75 C, and 0.175 g of the tetraalde-
the organic layer with water (3ꢂ30 mL). The organic layer
ꢀ
obtained in 91% (0.078 g) and 85% (0.250 g) yields, respec-
was then dried over MgSO , filtered, evaporated, and then
4
flash chromatographed (silica, 10–20% acetone in ethyl ace-
tate) to give 1 (80.1 mg). Further purification by crystalliza-
tion from benzene/heptane gave 63.3 mg (28% from two
crops) of 1. Another reaction, which was carried out at
room temperature using 65.4 mg of 6, gave tetraradical 1
(15.0 mg, 23%), after two successive recrystallizations. Mp
ꢀ
DMSO-d ): d 7.605 (s, 8H, OH, exch D O), 7.196 (s, 8H,
1
tively. Mp w270 C (under N , dec). H NMR (400 MHz,
2
6
2
ArH), 4.497 (s, 4H, CH), 3.847 (s, 8H, ArCH ), 3.355 (s,
2
8
1
H, OCH , under the H O peak from solvent), 3.104 (s,
2 2
2H, OCH ), 2.940 (t, 5.2 Hz, 8H, OCH ), 1.071 (s, 12H,
3
2
1
3
ꢀ
w200 C (under N , dec). H NMR (600 MHz, CDCl ,
2 3
1
CH ), 0.974 (s, 12H, CH ). C NMR (100 MHz, DMSO-
3
3
d6): d 156.3, 135.5, 133.1, 129.0, 90.4, 70.9, 69.4, 66.4,
8.7, 38.4, 25.0, 17.6. LR-FABMS (3-NBA matrix) m/z: cal-
culated for C H N O [M] 1289.6; found 1289.6. IR
68 mM): d 22.5 (v. br s, 8H, ArH), 5.63 (br s, 12H), 4.09
(br s, 24H), ꢁ13.6 (v. br s, 48H, C(CH ) ). LR-FABMS
5
3
2
+
(3-NBA matrix) cluster: m/z (% RA for m/z¼500–2000) at
6
8 104 8 16
ꢁ1
+
(
ZnSe, cm ): 3269, 2977, 2926, 1453, 1364, 1203, 1118.
(M) 1277.6 (13), 1278.6 (15), 1279.6 (17), 1280.6 (15),
1
+
281.6 (8), at (MꢁO) 1261.5 (25), 1262.5 (36), 1263.5
+
5
.10. Bis(1,3-dihydroimidazolidine) 7: 5,17-bis(1,3-
(31), 1264.5 (22), 1265.5 (13), at (Mꢁ2O) 1245.6 (25),
dihydroxy-4,4,5,5-tetramethylimidazolin-2-yl)-11,23-
dibromo-25,26,27,28-tetrakis(methoxyethoxy)calix[4]-
arene
1246.5 (68), 1247.5 (65), 1248.5 (42), 1249.5 (26), at
(Mꢁ3O) 1230.5 (88), 1231.5 (100), 1232.5 (70), 1233.5
+
+
(38), at (Mꢁ4O) 1212.5 (14), 1213.5 (27), 1214.5 (68),
1
215.5 (85), 1216.5 (72), 1217.5 (41), 1218.5 (17), at
+
A mixture of dialdehyde 5 (0.100 g, 0.115 mmol), 2,3-bis-
hydroxyamino)-2,3-dimethylbutane (85.2 mg, 0.575 mmol),
(Mꢁ5O) 1197.5 (12), 1198.5 (22), 1199.5 (28), 1200.5
(
(26), 1201.5 (17). HR-FABMS (3-NBA matrix): m/z (ion