Synthesis of Salicylaldimine Schiff Bases with Benzo-10-aza-15-crown-5 Pendant

Article abstract of DOI:10.1081/SCC-120030311

A series of azacrown ether substituted salicylaldimine Schiff bases 3a-c, 5a-c, and 6a-c have been synthesized by the condensation of salicylaldehyde with azacrown ether-containing arylamine or amino-compounds with azacrown ether-containing salicylaldehyde from benzo-10-aza-15-crown-5. The new structure was elucidated by spectral methods and confirmed by x-ray crystallographic analysis.

Full text of DOI:10.1081/SCC-120030311

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Synthesis of Salicylaldimine Schiff Bases with
Benzo‐10‐aza‐15‐crown‐5 Pendant
Xingyao Wei a , Zhihua Mao b , Jianzhang Li a & Shengying Qin a
a Department of Chemistry , Sichuan University , Chengdu, 610064, P.R. China
b Analytical and Testing Center , Sichuan University , Chengdu, P.R. China
Published online: 21 Aug 2006.
To cite this article: Xingyao Wei , Zhihua Mao , Jianzhang Li & Shengying Qin (2004) Synthesis of Salicylaldimine
Schiff Bases with Benzo‐10‐aza‐15‐crown‐5 Pendant, Synthetic Communications: An International Journal for Rapid
Communication of Synthetic Organic Chemistry, 34:7, 1237-1246, DOI: 10.1081/SCC-120030311
To link to this article: http://dx.doi.org/10.1081/SCC-120030311
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SYNTHETIC COMMUNICATIONSw
Vol. 34, No. 7, pp. 1237–1246, 2004
Synthesis of Salicylaldimine Schiff Bases
with Benzo-10-aza-15-crown-5 Pendant
Xingyao Wei,1 Zhihua Mao,2 Jianzhang Li,1 and
Shengying Qin1,
*
1Department of Chemistry and 2Analytical and Testing Center, Sichuan
University, Chengdu, P.R. China
ABSTRACT
A series of azacrown ether substituted salicylaldimine Schiff bases 3a–c,
5a–c, and 6a–c have been synthesized by the condensation of salicyl-
aldehyde with azacrown ether-containing arylamine or amino-com-
pounds with azacrown ether-containing salicylaldehyde from benzo-10-
aza-15-crown-5. The new structure was elucidated by spectral methods
and confirmed by x-ray crystallographic analysis.
Key Words: Salicylaldimine Schiff base; Condensation; Azacrown;
Arylamine.
Salicylaldimine Schiff bases, an important class of metal chelators, were
widely applied in the field of coordination chemistry,[1] analytical chemistry,[2]
*
Correspondence: Shengying Qin, Department of Chemistry, Sichuan University,
Chengdu 610064, P.R. China; E-mail: qin-shengying@163.com.
1237
DOI: 10.1081/SCC-120030311
0039-7911 (Print); 1532-2432 (Online)
www.dekker.com
Copyright # 2004 by Marcel Dekker, Inc.

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Wei et al.
and catalytic chemistry.[3] In recent years, there has been considerable interest
in the research of salicylaldimine Schiff bases transition-metal complexes as
oxygen carriers[4] and enzyme catalysis mimetics.[5,6] It was known that intro-
duction of substituents to the Schiff base ligands would favor the complexes to
form stable dioxygen adducts and avoid dimerizing and losing activity.[7]
Especially, crown ethers employed as the substituents have received much
attention[8,9] because of their binding ability to alkali ions and special configur-
ation. Our recent works have shown that dioxygen affinities and biomimetic
catalytic performance of transition-metal complexes with (15-crown-5) salo-
phen are better in comparison with crown-free analogs.[10] Azacrown ether
bearing salicylaldimine Schiff base ligands are good receptors for alkali and
transition-metal guest cations.[11] In order to investigate the effect of azacrown
ether ring possessing special stereo configuration and function on several
important properties, namely, the ability for complexation with metal ions
and biomimetic performance, herein, are described the synthesis of azacrown
ether-containing mono and bis-Schiff bases 3a–c, 5a–c, and 6a–c (Sch. 1).
As shown in Sch. 1, compound 1 underwent Mannich reaction to give key
intermediates 2. Then 2a and its derivatives 2b and 2c were reduced to amino
compounds without further isolation and purification to avoid their oxidation
Scheme 1.

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Synthesis of Salicylaldimine Schiff Bases
1239
in the air. Also, 1 followed another pathway to yield 5a–c, which were the iso-
mers of 3a–c. The crystal structure of 3a,a 5a,b and 6ac are shown in Figs. 1–3.
˚
Selected bond lengths (A) and angles (8) for x-ray structure of 3a are: O(1)–
. . .
. . .
. . .
Ho(1) N(1): O(1)–Ho(1) 0.97(7), Ho(1) N(1) 1.71(7), O(1) N(1)
. . . . . .
. . .
2.590(6). O(2)–Ho(2) N(2): O(2)–Ho(2) 0.77(5), Ho(2) N(2) 1.96(5),
O(2) N(2) 2.665(6). O(1)–C(6) 1.347(6). O(2)–C(11) 1.358(6). O(3)–
C(16) 1.419(5). O(3)–C(17) 1.429(6). O(4)–C(18) 1.409(7). O(4)–C(19)
1.371(8). O(5)–C(24) 1.388(7). O(5)–C(25) 1.413(9). O(6)–C(26) 1.421(6).
O(6)–C(27) 1.418(6). N(1)–C(7) 1.268(6). N(1)–C(8) 1.421(6). N(2)–
C(14) 1.473(7). N(2)–C(15) 1.492(6). N(2)–C(28) 1.493(6). C(10)–C(14)
1.519 (7). C(15)–C(16) 1.517(8). C(17)–C(18) 1.518(8). C(25)–C(26)
. . .
1.526(11). C(27)–C(28) 1.527(10). O(1)–Ho(1) N(1) 149(6). O(2)–
. . .
Ho(2) N(2) 152(5). C(7)–N(1)–C(8) 122.3(5). N(1)–C(7)–C(1)
122.8(6). C(14)–N(2)–C(15) 108.9(5). C(14)–N(2)–C(28) 113.0(5).
C(14)–N(2)–C(28) 112.9(5). C(16)–O(3)–C(17) 113.4(4). C(19)–O(4)–
(18) 116.4(6). C(24)–O(5)–(25) 117.8(8). C(26)–O(6)–(27) 106.8(8).
C(8)–N(1)–C(7)–C(1) 175.1(5). C(14)–N(2)–C(15)–C(16) 102.4(7).
C(28)–N(2)–C(15)–C(16)
2131.3(7).
C(15)–N(2)–C(14)–C(10)
2162.8(5). C(28)–N(2)–C(14)–C(10) 71.0(7). C(17)–O(3)– C(16)–C(15)
2169.9(6). C(19)–O(4)–C(18)–C(17) 170.0(5). C(18)–O(4)–C(19)–C(24)
2161.8(6). C(25)–O(5)–C(24)–C(19) 170.0(5). C(24)–O(5)–C(25)–C(26)
˚
2177.7(7). C(26)–O(6)–C(27)–C(28) 164.7(7). Selected bond lengths (A)
. . .
and angles (8) for x-ray structure of 5a are: O(2)–H(2) N(1): O(2)–H(2)
. . .
. . .
. . .
0.82, H(2) N(1) 1.83, O(2) N(1) 2.661(6). Ow–Hw(1) O(3): Ow–
. . . . . . . . .
Hw(1) 0.84, Hw(1) O(3) 2.19, Ow O(3) 2.880(6). Ow–Hw(2) O(6):
. . .
. . .
Ow–Hw(2) 1.10, Hw(2) O(6) 1.78, Ow O(6) 2.757(6). O(1)–C(1)
1.364(5). O(2)–C(13) 1.363(6). O(3)–C(16) 1.418(6). O(3)–C(17) 1.420(6).
O(4)–C(18) 1.433(6). O(4)–C(19) 1.361(5). O(5)–C(24) 1.370(6). O(5)–
C(25) 1.420(6). O(6)–C(26) 1.420(7). O(6)–C(27) 1.416(6). N(1)–C(7)
1.283(5). N(1)–C(4) 1.425(6). N(2)–C(28) 1.453(6). N(2)–C(14) 1.444(6).
Figure 1. X-ray structure of 3a.

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Wei et al.
Figure 2. X-ray structure of 5a.
N(2)–C(15) 1.470(8). C(10)–C(14) 1.510(7). C(15)–C(16) 1.508(9). C(17)–
C(18) 1.516(7). C(25)–C(26) 1.512(7). C(27)–C(28) 1.516(9). O(2)–
. . .
. . .
. . .
H(2) N(1) 147.2. Ow–Hw(1) O(3) 139.5. Ow–Hw(2) O(6) 145.6.
C(4)–N(1)–C(7) 123.1(4). N(1)–C(7)–C(8) 1221.0(5) C(14)–N(2)–C(28)
116.4(5). C(15)–N(2)–C(28) 106.7(5). C(14)–N(2)–C(15) 114.2(5).
C(16)–O(3)–C(17) 112.6(5). C(18)–O(4)–C(19) 116.9(4). C(24)–O(5)–
C(25) 117.0(4). C(26)–O(6)–C(27) 117.4(5). C(4)–N(1)–C(7)–C(8)
2178.2(4). C(14)–N(2)–C(15)–C(16) 78.1(6). C(15)–N(2)–C(14)–C(10)
2134.0(6). C(28)–N(2)–C(14)–C(10) 100.9(6). C(28)–N(2)–C(15)–C(16)
Figure 3. X-ray structure of 6a.

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Synthesis of Salicylaldimine Schiff Bases
1241
151.7(5). C(17)–O(3)–C(16)–C(15) 163.0(5). C(19)–O(4)–C(18) –C(17)
170.8(4). C(18)–O(4)–C(19)–C(24) 2156.7(5). C(25)–O(5)–C(24)–C(19)
160.6(5). C(24)–O(5)–C(25)–C(26) 2167.4(5). C(26)–O(6)–C(27)–C(28)
˚
153.8(5). Selected bond lengths (A) and angles (8) for x-ray structure of 6a
. . .
. . .
. . .
are: O(1)–H(1) N(1): O(1)–H(1) 0.82, H(1) N(1) 1.91, O(1) N(1)
2.643(10). O(1)–C(1) 1.373(9). O(2)–C(14) 1.383(9). O(2)–C(13) 1.448(8).
O(3)–C(12) 1.421(10). O(3)–C(11) 1.445(10). O(4)–C(21) 1.450(11).
O(4)–C(22) 1.410(11). O(5)–C(19) 1.381(11). O(5)–C(20) 1.437(10).
N(1)–C(7) 1.285(10). N(1)–C(8) 1.465(10). N(2)–C(10) 1.430(10). N(2)–
C(9) 1.432(9). N(2)–C(23) 1.477(10). C(4)–C(9) 1.505(11). C(10)–C(11)
1.534(13). C(12)–C(13) 1.547(11). C(20)–C(21) 1.505(12). C(22)–C(23)
. . .
1.506(12). O(1)–H(1) N(1) 148.6. C(7)–N(1)–C(8) 119.6(8). N(1)–
C(7)–C(6) 125.7(8). C(10)–N(2)–C(9) 112.9(7). C(10)–N(2)–C(23)
110.7(7). C(9)–N(2)–C(23) 109.7(8). C(14)–O(2)–C(13) 114.4(7). C(12)–
O(3)–C(11) 112.7(8). C(22)–O(4)–C(21) 110.6(8). C(19)–O(5)–C(20)
117.7(7). C(8)–N(1)–C(7)–C(6) 179.3(6). C(10)–N(2)–C(9)–C(4)
2172.7(9). C(23)–N(2)–C(9)–C(4) 63.3(10). C(9)–N(2)–C(10)–C(11)
92.2(9). C(23)–N(2)–C(10)–C(11) 2144.4(8). C(14)–O(2)–C(13)–C(12)
173.8(7). C(13)–O(2)–C(14)–C(19) 2160.1(7). C(12)–O(3)–C(11)–C(10)
2169.8(7). C(21)–O(4)–C(22)–C(23) 152.3(8). C(19)–O(5)–C(20)–C(21)
2172.8(8). C(20)–O(5)–C(19)–C(14) 171.3(7). Compound 5a was found
to combine with a water molecule by hydrogen bond, and this was in accord-
ance with its infrared (IR) spectra, 1H NMR, and elemental analysis data.
EXPERIMENTAL
Melting points were taken on a micro-melting apparatus and uncorrected.
IR spectra were recorded with a Nicolet-1705X infrared spectrophotometer
1
and frequencies reported in cm21. H NMR spectra were obtained with a
Brucker AC-E200, and chemical shifts in ppm are reported relative to tetra-
methylsilane. Mass spectra data were measured on a Finnigan MAT 95 and
Finnigan LCQDECA spectrometer. Elemental analyses were performed with
a Carlo Erba 1106 instrument. X-ray diffraction were measured on a Enraf–
Nornius CAD-4 diffractometer using graphite monochromated Mo Ka radi-
ation l ¼ 0.071073 nm. The structure was solved by direct methods using
the SHELXS 97 program.[12] The hydrogen atoms were theoretically added
or positioned by difference Fourier techniques, and included in the final refine-
ment model in calculated and fixed positions with isotropic thermal par-
ameters. A full-matrix least-squares refinement on F2 was carried out using
SHELXL 97.[13] Column chromatography was carried out using silica gel
(60H, Qingdao, China). Reagent and solvent were purified in the usual way.

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Wei et al.
General Procedure for the Preparation of N-(2-Alkyloxy-
5-nitrobenzyl)benzo-10-aza-15-crown-5 (2b–c)
A mixture of 1 (2.67 g, 0.01 mol) in benzene (50 mL) was treated with
4-nitrophenol (1.39 g, 0.01 mol) and paraformaldehyde (0.3 g, 0.011 mol)
under N2 and refluxed for 20 hr. The solvent was evaporated and the residual
solid was crystallized from ethanol to give 2a as yellow crystal, m.p. 146–
1
1488C; yield 81%. IR (KBr, vmax, cm21): 3423, 1625, 1332, 1257, 1136; H
NMR (CDCl3) d 8.07–7.89 (m, 4H, ArOH, ArH), 7.25–6.73 (m, 4H, ArH),
4.18–3.76 (m, 14H, OCH2, NCH2Ar), 2.86 (t, 4H, J ¼ 5.5 Hz, NCH2);
Anal. Calcd for C21H26N2O7: C60.29, H 6.22, N 6.70; found: C 60.17, H
6.29, N 6.79; MS (m/z): 418 (Mþ). A mixture of 2a (4.18 g, 0.01 mol) and cor-
responding bromoalkane (0.011 mol) in acetonitrile (30 mL) was refluxed in
the presence of K2CO3 (1.52 g, 0.011 mol) for 20 hr. The solvent was evapor-
ated and the residual mass was chromatographed on a silica gel column
(eluent: ethyl acetate) to afford the pure products.
1
2b: Yield 95%; oil; IR (neat, vmax, cm21): 1626, 1335, 1256, 1134; H
NMR (CDCl3) d 8.05–7.91 (m, 3H, ArH), 7.24–6.71 (m, 4H, ArH), 4.15–
3.77 (m, 16H, OCH2, NCH2Ar), 2.82 (t, 4H, J ¼ 5.5 Hz, NCH2), 1.82–0.86
(m, 13H, CH2, CH3); Anal. Calcd for C28H40N2O7: C 65.12, H 7.75, N
5.43; found: C 65.35, H 7.89, N 5.35; MS (m/z): 516 (Mþ).
1
2c: Yield 92%; oil; IR (neat, vmax, cm21): 1625, 1332, 1250, 1129; H
NMR (CDCl3) d 8.01–7.90 (m, 8H, ArH), 7.46–6.79 (m, 4H, ArH), 5.09
(s, 2H, ArCH2O), 4.15–3.69 (m, 14H, OCH2, NCH2Ar), 2.87 (t, 4H,
J ¼ 5.5 Hz, NCH2); Anal. Calcd for C28H32N2O7: C 66.14, H 6.30, N 5.51;
found: C 66.26, H 6.41, N 5.42; MS (m/z): 508 (Mþ).
General Procedure for the Preparation of
Mono-Schiff Bases 3a–c
.
A mixture of 2a–c (0.01 mol), SnCl2 2H2O (8.96, 0.04 mol), and ethanol
(100 mL) was refluxed for 6 hr under N2 and cooled. The mixture was added to
ice water and adjusted to pH 8 with 40% NaOH. After extraction (CH2Cl2,
3 ꢀ 20 mL), drying (MgSO4), and evaporation of solvent, the residue dis-
solved in ethanol (20 mL) was immediately mixed with salicylaldehyde
(1.22 g, 0.01 mol) and stirred at room temperature under N2 for 2 hr. The pre-
cipitate was collected by suction filtration and washed with cold ethanol. The
crude product was recrystallized from ethanol to give a pure sample.
3a: Yield 85%. Yellow crystal; m.p. 128–1308C. IR (KBr, vmax, cm21):
3445, 3222, 1618, 1256, 1128; 1H NMR (CDCl3) d 13.49 (brs, 1H, OH, D2O
exchangeable), 8.62 (s, 8.56, 1H, OH, D2O exchangeable), 8.56 (s, 1H,

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Synthesis of Salicylaldimine Schiff Bases
1243
N55CH), 7.36–6.78 (m, 11H, ArH), 4.18–3.77 (m, 14H, OCH2, NCH2Ar),
2.89 (t, 4H, J ¼ 5.6 Hz, NCH2); Anal. Calcd for C28H32N2O6: C 68.29, H
6.50, N 5.69; found: C 68.02, H 6.34, N 5.85; MS (m/z): 492 (Mþ).
3b: Yellow crystal; m.p. 68–708C. Yield 84%. IR (KBr, vmax, cm21):
1
3225, 1620, 1252, 1123; H NMR (CDCl3) d 13.55 (brs, 1H, OH, D2O
exchangeable), 8.65 (s, 1H, N55CH), 7.48–6.83 (m, 11H, ArH), 4.12–3.73
(m, 16H, OCH2, NCH2Ar), 2.86 (t, 4H, J ¼ 5.6 Hz, NCH2), 1.78–0.89
(m, 13H, CH2, CH3); Anal. Calcd for C35H46N2O6: C 71.19, H 7.80, N
4.75; found: C 71.30, H 7.89, N 4.63; MS (m/z): 590 (Mþ).
3c: Yellow crystal; m.p. 96–988C. Yield 86%. IR (KBr, vmax, cm21):
1
3227, 1618, 1256, 1125; H NMR (CDCl3) d 13.53 (brs, 1H, OH, D2O
exchangeable), 8.63 (s, 1H, N55CH), 7.54–6.83 (m, 16H, ArH), 5.11 (s, 2H,
ArCH2O), 4.11–3.78 (m, 14H, OCH2, NCH2Ar), 2.89 (t, 4H, J ¼ 5.6 Hz,
NCH2); Anal. Calcd for C35H38N2O6: C 72.16, H 6.53, N 4.81; found: C
72.24, H 6.69, N 4.69; MS (m/z): 582 (Mþ).
Preparation of N-(3-Formyl-4-hydroxybenzyl)benzo-10-aza-
15-crown-5 (4)
To a stirred mixture of 1 (2.67 g, 0.01 mol) and K2CO3 (1.52 g, 0.011 mol)
in acetonitrile (40 mL), a solution of 2-hydroxy-5-chloromethyl-benzaldehyde
(1.71 g, 0.01 mol) in acetonitrile (10 mL) was added dropwise within 1 hr. The
mixture was refluxed for 10 hr. Then the reaction mixture was filtered
and the solvent was evaporated. The residual mass was chromatographed on
a silica gel column (eluent: ethyl acetate) to give the pure product as oil,
yield 89%, IR (neat, vmax, cm21): 3247, 1652, 1257, 1125; 1H NMR
(CDCl3) d 10.78 (brs, 1H, OH, D2O exchangeable), 9.95 (s, 1H, N55CH),
7.42–6.81 (m, 7H, ArH), 4.15–3.76 (m, 14H, OCH2, NCH2Ar), 2.85 (t, 4H,
J ¼ 5.5 Hz, NCH2); Anal. Calcd for C22H27NO6: C 65.84, H 6.73, N 3.49;
found: C 65.59, H 6.57, N 3.61; MS (m/z): 401 (Mþ).
General Procedure for the Preparation of Mono-Schiff Bases
5a–c and bis-Schiff Bases 6a–c
Compound 4 (4.01 g, 0.01 mol) was dissolved in ethanol (20 mL) and
mixed with the amine (0.01 mol) or diamine (0.005 mol), and then stirred at
room temperature under N2 for 2 hr. The precipitate was collected by suction
filtration and washed with cold ethanol. The crude product was recrystallized
from ethanol to give a pure sample.
Compound 5a. Yellow crystals; Yield 85%; m.p. 95–978C. IR (KBr,
1
v
max, cm21): 3446, 3225, 1622, 1258, 1126; H NMR (CDCl3) d 13.65 (brs,

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Wei et al.
1H, OH, D2O exchangeable), 10.29 (s, 1H, OH, D2O exchangeable), 8.55
(s, 1H, N55CH), 7.41–6.85 (m, 11H, ArH), 4.18–3.77 (m, 14H, OCH2,
NCH2Ar), 2.83 (t, 4H, J ¼ 5.7 Hz, NCH2), 1.63 (brs, 2H, H2O); Anal.
.
Calcd for C28H34N2O7 (4a H2O): C 65.88, H 6.67, N 5.49; found: C 65.97,
H 6.49, N 5.56; MS (m/z): 492 (Mþ).
Compound 5b. Yellow crystals; Yield 90%; m.p. 80–828C; IR (KBr,
1
v
max, cm21): 3440, 3222, 1620, 1252, 1130; H NMR (CDCl3) d 13.40 (brs,
1H, OH, D2O exchangeable) 8.59 (s, 1H, N55CH), 7.43–6.86 (m, 11H,
ArH), 4.15–3.66 (m, 16H, OCH2, NCH2Ar), 2.82 (t, 4H, J ¼ 5.6 Hz,
NCH2), 1.82–0.86 (m, 13H, CH2, CH3), 1.63 (brs, 2H, H2O); Anal. Calcd
.
for C35H48N2O7 (4b H2O): C 69.08, H 7.89, N 4.61; found: C 68.95, H
7.97, N 4.75; MS (m/z): 590 (Mþ).
Compound 5c. Yellow crystals; Yield 87%; m.p. 88–908C. IR (KBr,
1
v
max, cm21): 3436, 3223, 1620, 1255, 1126; H NMR (CDCl3) d 13.42 (brs,
1H, OH, D2O exchangeable), 8.61 (s, 1H, N55CH), 7.45–6.84 (m, 16H,
ArH), 5.06 (s, 2H, ArCH2O), 4.12–3.76 (m, 14H, OCH2, NCH2Ar), 2.85
(t, 4H, J ¼ 5.6 Hz, NCH2), 1.63 (brs, 2H, H2O); Anal. Calcd for
.
C35H40N2O7 (4b H2O): C 70.00, H 6.67, N 4.67; found: C 70.16, H 6.55,
N 4.90; MS (m/z): 582 (Mþ)
Compound 6a. Yellow crystals; Yield 91%; m.p. 118–1208C. IR (KBr,
v
max, cm21): 3226, 1632, 1257, 1132; 1H NMR (CDCl3) d 13.12 (s, 2H, OH,
D2O exchangeable), 8.26 (s, 2H, N55CH), 7.26–6.80 (m, 14H, ArH), 4.13–
3.62 (m, 32H, OCH2, NCH2Ar, C55NCH2), 2.79 (t, J ¼ 5.6 Hz, 8H, NCH2);
Anal. Calcd for C46H58N4O10: C 66.83, H 7.02, N 6.78; found C 66.65, H
7.15, N 6.67; ESIMS (m/z): 826 (Mþ).
Compound 6b. Yellow crystal; Yield 86%. m.p. 62–648C. IR (KBr, vmax
,
cm21): 3225, 1636, 1255, 1128; H NMR (CDCl3) d 13.23 (s, 2H, OH, D2O
exchangeable), 8.29 (s, 2H, N55CH), 7.28–6.81 (m, 14H, ArH), 4.16–3.60
(m, 32H, OCH2, NCH2Ar, NCH2, C55NCH2), 2.78 (t, J ¼ 5.6 Hz, 8H,
NCH2), 1.55–1.61 (m, 2H, CCH2C); Anal. Calcd for C47H60N4O10: C 67.14,
H 7.14, N 6.67; found C 67.29, H 7.31, N 6.59; ESIMS (m/z): 840 (Mþ).
1
Compound 6c. Yellow crystal; Yield 89%. m.p. 147–1498C. IR (KBr,
1
v
max, cm21): 3223, 1618, 1255, 1127; H NMR (CDCl3) d 13.50 (s, 2H,
OH, D2O exchangeable), 8.35 (s, 2H, N55CH), 7.25–6.80 (m, 18H, ArH),
4.16–3.66 (m, 28H, OCH2, NCH2Ar), 2.81 (t, J ¼ 5.6 Hz, 8H, NCH2);
Anal. Calcd for C50H58N4O10: C 68.65, H 6.64, N 6.41; found C 68.73, H
6.76, N 6.35; ESIMS (m/z): 874 (Mþ).
NOTES
a. X-ray crystallography for 3a: empirical formula C28H32N2O6,
Fw ¼ 492.56, T ¼ 293(2) K, monoclinic, space group P21/a,

ORDER
REPRINTS
Synthesis of Salicylaldimine Schiff Bases
1245
˚
˚
˚
3
a ¼ 9.558(6) A, b ¼ 20.201(7) A, c ¼ 13.549(6) A, a ¼ 90.00(4)8,
˚
b ¼ 96.33(5)8, g ¼ 90.00(4)8, V ¼ 2600.0(2) A , Z ¼ 4, Dc ¼
1.258 mg/m3, m ¼ 0.089 mm21. 4517 reflections were measured.
4067 unique (Rint ¼ 0.0000) were used in all calculations.
F(000) ¼ 1048, 1.518 , u , 24.048, R ¼ 0.0651, wR ¼ 0.1581.
23
˚
S ¼ 0.913, largest diff. Peak and hole: 0.368 and 20.305 eA
.
b. X-ray crystallography for 5a: empirical formula C28H34N2O7,
Fw ¼ 510.57, T ¼ 293(2) K, monoclinic, space group P21/n,
˚
˚
˚
a ¼ 12.424(7) A, b ¼ 19.945(7) A, c ¼ 12.556(7) A, a ¼ 90.00(4)8,
3
˚
b ¼ 116.54(5)8, g ¼ 90.00(4)8, V ¼ 2783.0(2) A , Z ¼ 4, Dc ¼
1.218 mg/m3, m ¼ 0.088 mm21. 3785 reflections were measured.
3629 unique (Rint ¼ 0.0000) were used in all calculations.
F(000) ¼ 1088, 1.928 , u , 22.518, R ¼ 0.0606, wR ¼ 0.1446.
23
˚
S ¼ 0.850, largest diff. Peak and hole: 0.253 and 20.382 eA
.
c. X-ray crystallography for 6a: empirical formula C46H58N4O10,
Fw ¼ 826.96, T ¼ 286(2) K, triclinic, space group P-1,
˚
˚
˚
a ¼ 8.902(3) A, b ¼ 10.344(3) A, c ¼ 12.399(4) A, a ¼ 90.21(3)8,
3
˚
b ¼ 107.86(3)8, g ¼ 101.72(3)8, V ¼ 1061.3(6) A , Z ¼ 1, Dc ¼
1.294 mg/m3, m ¼ 0.091 mm21. 3321 reflections were measured.
3274 unique (Rint ¼ 0.0000) were used in all calculations.
F(000) ¼ 442, 1.738 , u , 24.028, R ¼ 0.0802, wR ¼ 0.1763.
23
˚
S ¼ 0.878, largest diff. Peak and hole: 0.291 and 20.291 eA
.
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Received in Poland September 30, 2003

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