B. Blanco et al. / Tetrahedron Letters 42 (2001) 9001–9003
9003
Preparation of (E,E,E,E)-1,6,11,16-tetrakis[(2,4,6-triiso-
propylphenyl)sulfonyl] - 1,6,11,16 - tetraazacycloicosa - 3,8,
13,18-tetraene (3aaaa). Typical procedure. A mixture of
(E)-N,N%-bis[(2,4,6-triisopropylphenyl)sulfonyl]-2-buten-
1,4-diamine, 1aa, (0.42 g, 0.68 mmol), 60% suspension of
sodium hydride (0.085 g, 2.04 mmol) and DMF (34 mL)
was heated at 90°C under magnetic stirring for 30 min.
Then,(E,E,E)-N,N%-bis[(2,4,6-triisopropylphenyl)sulfonyl]-
1,14 - dibromo - 5,10 - diazatetradeca - 2,7,12 - triene, (2aa),
(0.60 g, 0.68 mmol) was added and the mixture was
heated at 90°C for 24 h. After cooling at room tempera-
ture water was added and the solid formed was filtered
and partitioned between chloroform and water. The
organic layer was dried and evaporated and the residue
was digested with diethyl ether and with pentane, to
afford 3aaaa (0.45 g, 50% yield).11
MALDI-TOF MS m/z 1156.5 [M+K]+, 1140.4 [M+Na]+.
Compound 3bbbb (47% yield), mp 219–220°C; IR (KBr)
2922, 1597, 1340, 1160, 1091 cm−1; 1H NMR (CDCl3, 250
MHz) l=2.47 (s, 12H), 3.65 (br s, 16H), 5.47 (br s, 8H),
7.35 (d, J=8.5 Hz, 8H), 7.66 (d, J=8.4 Hz, 8H); 13C
NMR (CDCl3, 62.9 MHz) l=21.6, 49.2, 127.2, 129.7,
129.9, 136.4, 143.7; MALDI-TOF MS m/z 932.1 [M+
K]+, 916.1 [M+Na]+.
Compound 3cccc was prepared as for 3aaaa, inorganic
salts being removed by washing with water. It was
difficult to obtain in pure form due to low solubility.
MALDI-TOF mass spectrum of crude 3cccc indicated the
presence of minor amounts of the 40-membered ring (m/z
1839.1 [M+Na]+). A pure sample of 3cccc (0.34 g from
0.91 g of crude material) was obtained after two column
chromatographies on silica gel with chloroform contain-
ing 2–4% (v/v) of trifluoroacetic acid (TFA) and final
recrystallization from trifluoroethanol/trifluoroacetic
acid/water. Physical data are: mp 235–241°C; IR (KBr)
11. Selected data for all new compounds: Compounds 1aa,3b
1bb,3b 2aa,3a and 2bb3b have been already described.
Compound 1cc mp 174–177°C. It was prepared as for 1aa
and 1bb.3b
1594, 1495, 1337, 1241, 1166, 1155, 1091, 840, 549 cm−1
;
Compound 2cc mp 93–95°C. It was prepared as for 2aa.3a
Compound 3aaaa (50% yield), mp 249–251°C; IR (KBr)
1H NMR (CDCl3+20% TFA, 250 MHz) l=3.76 (br s,
16H), 5.60 (br s, 8H), 7.27 (m, 8H), 7.82 (m, 8H); 13C
NMR (CDCl3+20% TFA, 62.9 MHz) l=49.4, 117.0 (d,
J=22.9 Hz), 129.7, 129.9 (d, J=9.5 Hz), 133.8 (d, J=2.9
Hz), 165.8 (d, J=255.6 Hz); 19F NMR (CDCl3+20%
TFA, 235 MHz) l=−103.93 (s, with respect to tri-
fluoroacetic acid); MALDI-TOF MS m/z 947.1 [M+K]+,
931.2 [M+Na]+; ESIMS m/z 925.1 [M+NH4]+, 908.2 [M]+.
Correct elemental analyses were secured for products 1cc,
2cc, 3aabb and 3cccc.
2960, 1601, 1460, 1364, 1313, 1151 cm−1 1H NMR
;
(CDCl3, 250 MHz) l=1.72 (t, J=ca 7 Hz, 72H), 2.87
(septet, J=7.0 Hz, 4H), 3.74 (br s, 16H), 4.05 (septet,
J=6.5 Hz, 8H), 5.71 (br s, 8H), 7.12 (s, 8H); 13C NMR
(CDCl3, 62.9 MHz) l=23.5, 24.8, 29.2, 34.1, 47.5, 123.9,
130.1, 131.0, 151.5, 153.2; MALDI-TOF MS m/z 1363.8
[M+Na]+.
Compound 3aabb (73% yield), mp 68–70°C; IR (KBr)
2959, 1600, 1463, 1339, 1161 cm−1; 1H NMR (CDCl3, 250
MHz) l=1.26 (t, J=7.4 Hz, 36H), 2.46 (s, 6H), 2.92
(septet, J=7.0 Hz, 2H), 3.73 (m, 16H), 4.08 (septet,
J=6.6 Hz, 4H), 5.50–5.72 (m, 8H), 7.17 (s, 4H), 7.33 (d,
J=8.4 Hz, 4H), 7.68 (d, J=8.3 Hz, 4H); 13C NMR
(CDCl3, 62.9 MHz) l=21.3, 23.3, 24.5, 29.0, 33.9, 47.3,
48.8, 49.0, 123.7, 126.9, 129.6, 129.7, 130.6, 136.1;
12. Crystallographic data (excluding structure factors) for the
structure in this paper have been deposited with the
Cambridge Crystallographic Data Center as supplemen-
tary publication number CCDC172445. Copies of the
data can be obtained, free of charge, on application to
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK [fax:
+44 (0) 1223-336033 or e-mail: deposit@ccdc.cam.ac.uk].