Heterocalixarenes Part 3: Bis-oxo-bridged calix[1]cyclicurea[3]arene and calix[1]cyclicurea[1]pyridine[2]arenes. Synthesis, X-ray crystal structure and conformational analysis

Article abstract of DOI:10.1039/a906883j

The Friedel-Crafts aroylations of 2- and 4-methylanisole with isophthaloyl dichloride or pyridine-2,6-dicarbonyl dichloride provide respective diones, which on bromination with NBS provide corresponding bisbromomethyl derivatives that undergo simple cyclo

Full text of DOI:10.1039/a906883j

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Heterocalixarenes Part 3: Bis-oxo-bridged calix[1]cyclicurea[3]arene
and calix[1]cyclicurea[1]pyridine[2]arenes. Synthesis, X-ray crystal
structure and conformational analysis1
1
Subodh Kumar,* Dharam Paul, Geeta Hundal, Maninder Singh Hundal and Harjit Singh*
Department of Chemistry, Guru Nanak Dev University, Amritsar-143 005, India
Received (in Cambridge, UK) 24th August 1999, Accepted 19th January 2000
The Friedel–Crafts aroylations of 2- and 4-methylanisole with isophthaloyl dichloride or pyridine-2,6-dicarbonyl
dichloride provide respective diones, which on bromination with NBS provide corresponding bisbromomethyl
derivatives that undergo simple cyclocondensations with embedded cyclicurea-containing heterocycles, viz.
benzimidazol-2(1H)-one, 5-nitrobenzimidazol-2(1H)-one, 5,6-dinitrobenzimidazol-2(1H)-one, uracil and
quinazoline-2,4(1H,3H)-dione to form 11 new bis-oxo-bridged heterocalix[4]arenes (11–19, 24, 25). The X-ray
crystal structure of the 11–benzene complex, 1H–1H COSY spectra and energy-minimization studies assign partial
cone conformations to these heterocalix[4]arenes. The variation in the cyclicurea moiety controls the flexibility
of these heterocalix[4]arenes.
The derivatizations on the upper and/or lower rims of con-
ventional calix[n]arenes2 and replacement of their phenylene
units with heterocyclic moieties3 provide tremendous novel
opportunities for generating receptors with unique inclusion/
complexation characteristics and related non-covalent host–
guest interactions. Whereas extensive work has been done on
the modification of hydroxy and para-alkyl groups,2 modifi-
cations on the methylene bridge(s) in the backbone of calix-
arenes have been only recently studied.4,5 The presence of alkyl
and/or aryl group(s) on a methylene carbon creates new stereo-
chemical centres and thus affects the geometries of the resulting
calixarenes.4 The presence of two bridge(s) in calixarenes
could further increase their versatility both due to possible
participation of carbonyl group in binding and to their being
a chemically reactive and prochiral centre. So far the synthesis
of oxo-bridged calixarenes through oxidation of preformed
calixarenes has not met with much success.5 The cyclizations
of preformed oxo-bridged precursors have provided monooxo-
bridged calix[4/5/6]arenes,4d which exhibit a strong intramolec-
ular H-bonding between carbonyl oxygen and an adjacent
phenolic OH group and result in greater conformational
flexibility than the parent calixarenes.
In the present investigations, a simple, high yielding, three-
step approach, involving Friedel–Crafts aroylation as a key step,
has been used to synthesize eleven new heterocalix[4]arenes
(11–19, 24, 25) possessing two carbonyl units in place of
methylene spacers and one or two heterocyclic units in place of
phenylene rings. The 1H NMR, 1H–1H COSY spectra and
energy-minimization studies define partial cone conform-
ations to these calixarenes, which has been confirmed in one
case, i.e. the 11–benzene complex, by X-ray crystal-structure
determination.
2(1H)-one 6 under solid–liquid phase-transfer catalytic (PTC)
conditions [CH3CN–K2CO3–tetrabutylammonium hydrogen
sulfate (TBAHSO4)] provides bisoxocalix[1]benzimidazol-
2(1H)-one[3]arene 11 (70%), mp 352–354 ЊC, Mϩ 504
(Scheme 1). Similarly, 4a reacts with 5-nitrobenzimidazol-
2(1H)-one (7), 5,6-dinitrobenzimidazol-2(1H)-one 8, uracil
9 and quinazoline-2,4(1H,3H)-dione 10 under PTC conditions
to provide, respectively, heterocalix[4]arenes 13 (35%), mp
>355 ЊC, Mϩ 549; 14 (45%), mp >355 ЊC, Mϩ 594; 16 (60%),
mp 333–335 ЊC, Mϩ 482 and 18 (65%), mp 337–339 ЊC, Mϩ 532.
Similarly, the reaction of 2-methylanisole 1a with pyridine-2,6-
dicarbonyl dichloride 2b provides 3b (60%), mp 155 ЊC, Mϩ
375. The bromination of 3b to 4b and subsequent cyclizations
with heterocycles 6, 9 and 10 provide, respectively, heterocalix-
[4]arenes 12 (45%), mp 299 ЊC, Mϩ 505; 17 (40%), mp 335 ЊC,
Mϩ 483 and 19 (45%), mp 320 ЊC, Mϩ 533. Friedel–Crafts
aroylation of 1b with 2a, subsequent NBS bromination,
and cyclization with 8 provides heterocalixarene 15 (12%), mp
319–320 ЊC, Mϩϩ1 791.
Friedel–Crafts aroylation of 4-methylanisole 20 with iso-
phthaloyl dichloride 2a (2:1) in chloroform in the presence of
AlCl3 (anhydrous) provides 21 (17%), thick liquid, Mϩ 286 and
22 (28%), mp 80 ЊC, Mϩ 374. The bromination of 22 with NBS
provides dibromide 23 (79%), mp 40 ЊC, Mϩ 530, 532, 534
(1:2:1). The intermolecular cyclocondensations of 23 with 6
and 9 provide heterocalix[4]arenes 24 (33%), mp 240 ЊC, Mϩ
504, and 25 (10%), mp 280 ЊC; Mϩ 482 (Scheme 2).
Conformational analysis
(A) Solid state – X-ray. Compound 11, on recrystallization
from chloroform–benzene (1:1 v/v mixture), forms a 11–benz-
ene complex of 1:1 stoichiometry. The X-ray crystal structure
(Fig. 1) of the 11–benzene complex reveals a typical calix inclu-
sion complex, where 11 attains partial cone conformation with
the isophthaloyl unit (ring A) placed in an opposite (anti) direc-
tion to the rest of the rings (Fig. 2). The torsion angles6 φ and χ
around connecting methylene and carbonyl carbons C(8),
C(16), C(23) and C(31) change their signs as ϩ Ϫ, ϩ Ϫ, ϩ ϩ
and Ϫ Ϫ, indicating a partial cone conformation2d (Table 1).
These four connecting carbons deviate approximately 0.08 Å
from their best fitted mean plane. The interplanar angles
between this plane and benzimidazol-2-(1H)-one ring (C) and
Results and discussion
Synthesis
Friedel–Crafts aroylation of 2-methylanisole 1a with iso-
phthaloyl dichloride 2a (2:1) in chloroform in the presence of
AlCl3 (anhydrous) provides 3a (65%), mp 136 ЊC, Mϩ 374. The
bromination of 3a with N-bromosuccinimide (NBS) provides
dibromide 4a (80%), mp 120 ЊC, Mϩ 530, 532, 534 (1:2:1). The
intermolecular cyclocondensation of 4a with benzimidazol-
DOI: 10.1039/a906883j
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This journal is © The Royal Society of Chemistry 2000
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Scheme 1 Reagents and conditions: (i) AlCl3, CHCl3, stirring, 40 ЊC; (ii) NBS, CCl4, reflux; (iii) K2CO3–CH3CN–TBAHSO4, reflux.
Scheme 2 Reagents and conditions: (i) AlCl3, CHCl3, stirring, 40 ЊC; (ii) NBS, CCl4, reflux; (iii) K2CO3–CH3CN–TBAHSO4, reflux.
isophthaloyl ring (A) are 57.7(1)Њ and 53.7(1)Њ whereas the two
methoxy aryl rings B and BЈ are making dihedral angles
42.8(1)Њ and 48.5(1)Њ, respectively, The dihedral angle between
rings B and BЈ, and between A and C, are 91.3(2)Њ and 4.1(1)Њ,
respectively, showing that the two methoxy aryl rings are
almost perpendicular whereas the benzimidazol-2-(1H)-one
ring ‘C’ and isophthaloyl unit ring ‘A’ are parallel to each other
(Fig. 2). The two rings in pairs A, C and B, BЈ are placed 7.4(1)
Å and 6.8(1) Å apart, respectively giving rise to an almost
square cavity. Both the methoxy groups are anti with respect to
the aryl ring B and BЈ (Table 1) and remain exocyclic to the
cavity.
1038
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Fig. 3 Packing diagram of 11–benzene complex showing H-bonding
and π–π interactions.
Fig. 1 Prospective view of 11–benzene complex, showing the atom-
labelling scheme.
Fig. 4 When X = N, Ha proton label is omitted.
Table 2 H-bonding interactions (distance in Å and angle in Њ) for
complex 11–benzene
X ؒ ؒ ؒ O
H ؒ ؒ ؒ O
ЄX ؒ ؒ ؒ H ؒ ؒ ؒ O
C(11) ؒ ؒ ؒ O(1) (i)
C(15) ؒ ؒ ؒ O(1) (i)
C(8) ؒ ؒ ؒ O(3) (ii)
C(31) ؒ ؒ ؒ O(4) (ii)
3.42
3.37
3.36
3.39
2.54
2.50
2.51
2.62
158.8
151.5
146.0
146.4
(i) x, Ϫy, z ϩ 1/2; (ii) x, y ϩ 1, z
an isophthaloyl ring on other side. This gives a stacking of
molecules down the ‘b’ axis (Fig. 3).
Apart from these π–π interactions, different molecules are
held together by weak C ؒ ؒ ؒ O intermolecular H-bonds (Fig. 3).
Imide carbonyl oxygen O(1) is H-bonded to carbon C(15) of
the methoxy group and aromatic carbon C(11) of aryl unit B,
whereas the oxygens of the bridging carbonyl groups, O(3) and
O(4), are H-bonded to the bridging methylene carbons C(8)
and C(31), respectively (Table 2).
Fig. 2 The side view of the 11–benzene complex, showing partial cone
conformation of 11 and placement of benzene with respect to
benzimidazol-2(1H)-one of 11.
Table 1 Important torsion angles (Њ) for complex 11–benzene
1
C(25)–C(26)–C(31)–N(1)
C(26)–C(31)–N(1)–C(1)
C(1)–N(2)–C(8)–C(9)
N(2)–C(8)–C(9)–C(14)
C(14)–C(13)–C(16)–C(17)
C(13)–C(16)–C(17)–C(22)
C(22)–C(21)–C(23)–C(24)
C(21)–C(23)–C(24)–C(25)
C(15)–O(2)–C(10)–C(9)
C(30)–O(5)–C(27)–C(26)
74.6(7)
Ϫ86.6(6)
90.4(6)
Ϫ71.1(6)
21.3(8)
(B) Solution phase – H NMR. The rationalization of multi-
plicities and chemical shifts of various proton signals in the 1H
NMR spectra and a comparison with their acyclic counterparts
provides a useful tool for assigning the geometries of calix-
arenes. Assignments of the chemical shifts of various protons
52.9(7)
have been carried out by decoupling experiments and H–1H
1
Ϫ39.7(8)
Ϫ35.0(8)
166.8(5)
Ϫ179.2(5)
COSY spectra. For presentation of these data, as far as possible
a uniform labelling pattern (Fig. 4) has been adopted. In the
case of pyridine-containing calixarenes, as one CH has been
replaced by ᎐N-, the Ha label has been omitted.
᎐
1
The solvent benzene molecule deviates significantly from
planarity, having a maximum rms deviation of 0.09 Å from a
least-square plane. This may be due to slight disorder in the
ring. The benzene molecule exhibits a face-to-face π–π inter-
action with the benzimidazol-2(1H)-one unit at a distance of
4.08(1) Å (Fig. 3). The dihedral angle between the mean plane
of these two rings is 19.7(2)Њ. The benzimidazol-2(1H)-one ring
also shows an intermolecular face-to-face π–π interaction with
the isophthaloyl ring of the symmetry-related molecule (x,
y ϩ 1, z), at 3.67(1) Å. Therefore, the benzimidazol-2(1H)-one
ring is sandwiched between a benzene molecule on one side and
The H NMR spectrum of 11 in CDCl3 shows one singlet
due to 2 × OMe protons, one broad singlet at δ 5.10 due to
two NCH2 units and signals for ArH. In the aromatic region,
irradiation of the triplet (δ 7.54), which is obviously due to the
Hc proton, converts the multiplet at δ 7.75–7.81 into a distorted
singlet. So, the signals of Hb protons are embedded in this
multiplet. Similarly, irradiation of the double doublet at δ 8.03
changes the pattern of the multiplet (δ 7.02–7.13), and thus
the signals of Hf protons are embedded into this multiplet. In
the H–1H COSY spectrum of 11, the triplet (Hc) shows one
1
cross-peak at δ 7.79 (Hb, doublet). This doublet (δ 7.79) has one
J. Chem. Soc., Perkin Trans. 1, 2000, 1037–1043
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Table 3 Nature of NCH2 signals and change in the chemical shift of
the protons Ha and Hd in heterocalixarenes 11–19, 24 and 25 with
respect to acyclic precursors
Change in chemical shift
of Ha and Hd
Nature of NCH2
protons
Ha
Hd
11
16
18
13
14
15
12
17
19
24
25
Broad singlet
Broad AB quartet
AB quartet
Sharp singlet
Sharp singlet
Sharp singlet
AB quartet
AB quartet
AB quartet
Sharp singlet
Sharp singlet
Ϫ0.8
Ϫ0.6
Ϫ0.6
Ϫ0.6
Ϫ0.6
Ϫ0.6
Ϫ0.1
Ϫ0.5
Ϫ0.9
<Ϫ0.1
Ϫ0 0.1
<Ϫ0.1
Ϫ0.7 0.1
Ϫ0.8 0.1
Ϫ1.3 0.1
Ϫ0.3
Fig. 5 Energy-minimized partial cone structure of calix[4]arene 11.
Ϫ0.7
Ϫ0.7
unit in these calix[4]arenes. The upfield shift of the protons Ha
(∆δ Ϫ0.7) as compared with the acyclic precursors revealed that
the isophthaloyl ring is perpendicular to the anisole units and
thus Ha faces the π-electron ring currents of these adjacent
anisole units. Even in 24 and 25 the change in position of
the OMe group does not affect their conformations. In the
1H NMR spectra, the NCH2 signals of benzimidazol-2(1H)-
one and its nitro derivatives heterocalix[4]arenes (11–15
and 24), appear as singlets (except for 12), but in the case of
uracil-based heterocalix[4]arenes (16, 17 and 25), NCH2
appears as two broad singlets or as two AB quartets, and in case
of quinazoline-2,4(1H,3H)-dione-based heterocalix[4]arenes
(18 and 19) NCH2 appears as two AB quartets. Apparently,
while moving from benzimidazol-2(1H)-one → uracil →
quinazoline-2,4(1H,3H)-dione moieties, the rigidity in con-
formations of the respective calixarenes increases. As a result,
the anisole rings undergo slow rotation (NMR time scale) and
Hd, which faces the π-cloud of the opposite ring, is shifted
upfield by δ 0.5–1.3. Therefore, these heterocalix[4]arenes
possess variable flexibility depending on the nature of the
heterocyclic moiety(ies).
<Ϫ0.1
cross-peak at δ 7.29 (Ha, singlet). The double doublet (δ 8.03),
which is obviously due to the He proton, has two cross-peaks
δ 7.75 (Hd, singlet) and δ 7.03 (Hf, doublet). The H NMR
1
spectrum of 11 in CDCl3 ϩ TFA shows an AB quartet (5.03,
5.43, J 17 Hz) due to the NCH2 protons.
The 1H NMR spectrum of 12 in CDCl3 shows one singlet at
δ 4.05 due to OMe protons, one AB quartet at δ 4.95, 5.27 due
to two NCH2 groups, one singlet at δ 6.96 due to four benz-
imidazolone aromatic Hs, three doublets at δ 7.05, 7.41 and
7.53 due to Hf, Hd and Hb, respectively, one triplet at δ 7.87 due
to Hc and one double doublet at δ 8.11 due to 2 × He protons.
1
The well defined H NMR spectrum and presence of one AB
quartet due to the NCH2 groups point toward a rigid conform-
ation in solution phase. Correlation in various proton signals
has been determined by decoupling experiments.
The 1H NMR spectrum of 16 in CDCl3 ϩ TFA exhibits two
singlets (δ 3.98, 4.01) for OMe, three broad singlets (δ 4.52, 5.05,
5.42) for two NCH2 groups, two doublets (δ 7.09, 7.13) for two
aromatic Hf, one multiplet (δ 8.01–8.10) for four aromatic He,
HeЈ, Hb and HbЈ, one singlet (δ 7.46) for Ha, one triplet (δ 7.78)
for Hc, one broad singlet (δ 7.41) for Hd and HdЈ, and two
doublets (δ 6.15, 7.59) for uracil H. Thus the non-equivalence
of N-1 and N-3 positions of the uracil creates a dissymmetry in
the calixarene.
MMX energy-minimization studies7 on these heterocalix[4]-
arenes reveal that all of them have by-and-large similar con-
formations. In these conformations the isophthaloyl ring is
placed perpendicular to the adjacent phenylene rings, as shown
1
in their X-ray and H NMR spectra. The energy-minimized
conformation of the representative case of the heterocalix[4]-
arenes 11 is shown in Fig. 5.
In the 1H NMR spectrum of 18, two OMe groups appear as
two singlets at δ 4.05 and 4.09, two NCH2 group constitute two
AB quartets, and remaining protons appear in a well defined
Therefore, Friedel–Crafts aroylation of 2- or 4-methylanisole
or 2-methylphenyl octyl ether with isophthaloyl dichloride or
pyridinedicarbonyl dichloride constitutes a key step of the
three-step methodology developed for the synthesis of bis-oxo-
bridged heterocalix[4]arenes. The X-ray crystal structure of
the 11–benzene complex, as well as 1H NMR and energy-
minimization studies, define an inward flattened partial cone
conformation to these calixarenes. The flexibility in these
heterocalixarenes is affected by the nature of the cyclic urea
moiety present.
pattern in the aromatic region. In the H–1H COSY spectrum
1
of 18, two triplets (δ 7.40, 7.74) have cross-peaks against each
other. Obviously, these triplets are due to Hh and Hi. Also, both
of these triplets have cross-peaks at δ 7.15 and 8.15. These two
peaks are, obviously, due to Hg and Hj. Because of Hg being
ortho to the carbonyl group, the downfield signal (δ 8.15)
could be assigned to Hg. Accordingly, the doublet at δ 7.15 is
due to Hj, the triplet at δ 7.74 due to Hh and the triplet at δ 7.40
due to Hi. Now the triplet at δ 7.58 (Hc) has one cross-peak at
δ 7.85 (m, Hb and HbЈ) and it has one more cross-peak at δ 7.49
(s, Ha). Similarly, the two multiplets δ 7.12–7.22 and 8.11–8.24
have a correlation and the second multiplet has two cross-peaks
at δ 6.93 and 7.01, which are obviously due to Hd and HdЈ. The
well defined nature of the spectrum and the appearance of two
NCH2 groups as two AB quartets show that the conformation
is rigid and the non-equivalence of two cyclic urea nitrogens
creates a dissymmetry in the molecule. The heterocalixarenes 17
Experimental
General
For general experimental details see ref. 8. In 13C NMR spectral
data, the ϩve and Ϫve signals correspond to a DEPT-135
spectrum, and ‘ab’ corresponds to quaternary carbon signals,
which are absent in DEPT-135 but appear in a normal
13C NMR spectrum. 5-Nitrobenzimidazol-2(1H)-one and 5,6-
dinitrobenzimidazol-2(1H)-one were prepared according to
the reported procedures.9
1
and 19 show similar patterns in their H NMR spectra, which
reveal that the conformations are similar.
The change in chemical shifts of Ha and Hd in these calix-
arenes as compared with those H in their precursors is given in
Table 3. It may be seen that in all heterocalix[4]arenes 11–19,
24, 25, Ha are shifted upfield by the same order (∆δ Ϫ0.7 0.1),
which points toward a similar placement of the isophthaloyl
Synthesis of the diones 3a,b, 5a and 22. General procedure
A solution of isophthaloyl dichloride 2a (10.0 g, 0.05 mol)
in chloroform (200 ml) containing suspended AlCl3 (anhyd.)
1040
J. Chem. Soc., Perkin Trans. 1, 2000, 1037–1043

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(13.5 g, 0.11 mol) was stirred for 2 h. The solution of 2-
methylanisole 1a (18.3 g, 0.15 mol) in chloroform (20 ml) was
added dropwise during 30 min. The mixture was stirred for 48 h
and then refluxed for 15 min to ensure the completion of the
reaction. After cooling in an ice-bath, the reaction mixture was
quenched with methanol (30 ml) and washed with water. The
organic layer was dried over Na2SO4 (anhyd.). The chloroform
layer was distilled and the residue was crystallized from
methanol–dichloromethane mixture to give the pure dione 3a.
Similarly, the reaction of the pyridinedicarbonyl dichloride 2b
with 2-methylanisole 1a gave the dione 3b. Similar reactions of
4-methylanisole 20 and 2-methylphenyl octyl ether 1b with
isophthaloyl dichloride provided a mixture of mono ketone 21
and dione 22, and 5a, respectively, which were purified by
column chromatography.
Synthesis of dibromides 4a,b, 5b and 23. General procedure
A solution of dione 3a (4.0 g, 0.011 mol) in CCl4 (200 ml)
containing suspended NBS (4.09 g, 0.023 mol) and benzoyl
peroxide (50 mg) was refluxed for 2 h. The solid that separated
was filtered off, the filtrate was distilled under vacuum, and the
residue was crystallized from methanol to give pure dibromide
4a. Similarly, bromination of diones 3b, 5a and 22 provided the
dibromides 4b, 5b and 23.
4a: (80%); mp 120 ЊC; m/z 530, 532, 534 (Mϩ, 1:2:1), 451,
453, 455 (Mϩ Ϫ Br); δH(CDCl3) 3.98 (6H, s, 2 × OCH3), 4.51
(4H, s, 2 × CH2), 6.93 (2 H, d, J 8.6 Hz, Hf), 7.62 (1H, t, J 7.6
Hz, Hc), 7.78 (2H, d, J 8.6 Hz, He), 7.86 (2H, s, Hd), 7.94 (2H,
d, J 7.6 Hz, HB), 8.05 (1H, s, Ha); δC(CDCl3) (normal/DEPT-
135) 27.62 (Ϫve, CH2), 55.43 (ϩve, OCH3), 109.72 (ϩve,
ArCH), 125.33 (ab, C), 126.08 (ϩve, CH), 127.99 (ab, C),
133.55 (ϩve, CH), 133.81 (ϩve, CH), 137.88 (ϩve, CH), 153.29
3a: (65%); mp 136 ЊC (from CH2Cl2 ϩ MeOH); m/z 374 (Mϩ);
δH(CDCl3), 2.26 (6H, s, 2 × CH3), 3.91 (6H, s, 2 × OCH3), 6.87
(2 H, d, J 8.4 Hz, ArH), 7.57–7.70 (5H, m, ArH), 7.96 (2H, d,
J 8.4 Hz, ArH), 8.06 (1H, s, ArH); δC(CDCl3) (normal/DEPT-
135) 16.26 (ϩve, CH3), 55.49 (ϩve, OCH3), 109.04 (ϩve, ArCH),
126.92 (ab, ArC), 128.26 (ϩve, ArCH), 129.18 (ab, ArC),
130.67 (ϩve, ArCH), 132.60 (ϩve, ArCH), 138.47 (ab, ArC),
(ab, C), 160.74 (ab, C), 189.54 (ab, C᎐O); νmax(KBr)/cmϪ1 1602
᎐
(C᎐O), 1647 (C᎐O) (Found: C, 53.8; H, 4.1. C H Br O
᎐
᎐
24 20
2
4
requires C, 54.13; H, 3.76%).
4b: (60%); mp 141 ЊC (from CHCl3); m/z Mϩ (absent), 454,
452 (Mϩ Ϫ Br); δH(CDCl3) 3.98 (6H, s, 2 × OCH3), 4.40 (4H, s,
2 × CH2), 6.91 (2H, d, J 8.6 Hz, Hf), 8.10–8.30 (7H, m, ArH);
δC(CDCl3 ϩ DMSO) (normal/DEPT-135) 27.62 (Ϫve, CH2),
55.43 (ϩve, OCH3), 109.72 (ϩve, ArCH), 125.33 (ab, ArC),
126.08 (ϩve, ArCH), 127.99 (ab, ArC), 133.55 (ϩve, ArCH),
133.81 (ϩve, ArCH), 137.88 (ϩve, ArCH), 153.29 (ab, ArC),
160.73 (abt, C), 189.54 (ab, C᎐O); νmax(KBr)/cmϪ1 1601 (C᎐O),
161.74 (ab, ArC), 194.90 (ab, C᎐O); νmax(KBr)/cmϪ1 1600,
᎐
(C᎐O), 1650 (C᎐O), 1670 (C᎐O) (Found: C, 77.2; H, 6.4.
᎐
᎐
᎐
C24H22O4 requires C, 77.01; H, 5.88%).
3b: (60%); mp 155 ЊC (from CHCl3); m/z 375 (Mϩ); δH(CDCl3)
2.16 (6H, s, 2 × CH3), 3.89 (6H, s, 2 × OCH3), 6.79 (2H, d, J 8.4
Hz, ArH), 8.02–8.21 (7H, m, ArH); δC(CDCl3) (normal/DEPT-
135) 16.17 (ϩve, CH3), 55.51 (ϩve, OCH3), 108.96 (ϩve, CH),
126.32 (ϩve, CH), 128.34 (ab, C), 131.93 (ϩve, CH), 133.73
(ϩve, CH), 138.00 (ϩve, CH), 154.59 (ab, C), 161.97 (ab, C),
191.30 (ab, C᎐O); νmax(KBr)/cmϪ1 1655 (C᎐O), 1650 (C᎐O),
᎐
᎐
1650 (C᎐O) (Found; C, 51.9; H, 3.9; N, 2.9. C H Br NO
᎐
23 19
2
4
requires C, 51.78; H, 3.56; N, 2.62%).
5b: (50%); mp 60 ЊC; m/z 647, 649 (Mϩ Ϫ Br); δH(CDCl3)
0.90 (6H, t, J 6.4 Hz, 2 × CH3), 1.17–1.54 (20H, m, 10 × CH2),
1.89 (4H, p, J 6.4 Hz, 2 × CH2), 4.09 (4H, t, J 6.4 Hz,
2 × OCH2), 4.54 (4H, s, 2 × BrCH2), 6.92 (2H, d, J 8.0 Hz,
2 × Hf), 7.60 (1H, t, J 7.6 Hz, Hc), 7.78 (2H, d, J 8.0 Hz,
2 × He), 7.87 (2H, s, Hd), 7.95 (2H, d, J 7.6 Hz, 2 × Hb), 8.06
(1H, s, Hc); δC(CDCl3) (normal/DEPT-135) 14.03 (ϩve, CH3),
22.62 (Ϫve, CH2), 26.12 (Ϫve, CH2), 26.22 (Ϫve, CH2), 29.18
(Ϫve, CH2), 29.32 (Ϫve, CH2), 31.76 (Ϫve, CH2), 68.02 (Ϫve,
OCH2), 109.93 (ϩve, ArCH), 126.79 (ϩve, ArCH), 128.14 (ab,
C), 128.88 (ab, C), 130.52 (ϩve, ArCH), 132.46 (ab, C), 132.56
᎐
᎐
᎐
1599 (C᎐O) (Found: C, 73.7; H, 5.4; N, 3.9. C H N O
᎐
23 21
1
4
requires C, 73.60; H, 5.60; N, 3.73%).
5a: (70%); mp 58 ЊC (from EtOH); m/z 570 (Mϩ); δH(CDCl3)
0.88 (6H, t, J 6.4 Hz, 2 × CH3), 1.16–1.47 (20H, m, 10 × CH2),
1.83 (4H, q, J 6.4 Hz, 2 × CH2), 2.25 (6H, s, 2 × CH3), 4.02 (4H,
t, J 6.4 Hz, 2 × OCH2), 6.81 (2H, d, J 6.8 Hz, 2 × ArH), 7.54–
7.67 (5H, m, 5 × ArH), 7.93 (2H, d, J 6.8 Hz, 2 × ArH), 8.03
(1H, s, ArH); δC(CDCl3) (normal/DEPT-135) 14.03 (ϩve,
CH3), 16.22 (ϩve, CH3), 22.58 (Ϫve, CH2), 26.04 (Ϫve, CH2),
29.16 (Ϫve, CH2), 29.25 (Ϫve, CH2), 31.73 (Ϫve, CH2), 68.06
(Ϫve, OCH2), 109.88 (ϩve, ArCH), 126.81 (ϩve, ArCH),
128.04 (ab, C), 128.94 (ab, C), 130.49 (ϩve, ArCH), 132.36
(ab, C), 132.55 (ab, C), 138.48 (ab, C), 161.15 (ab, C), 194.27
(ab, C᎐O); νmax(KBr)/cmϪ1 1605 (C᎐O), 1652 (C᎐O), 1676
(ab, C), 138.48 (ab, C), 161.22 (ab, C), 193.67 (ab, C᎐O); ν
-
᎐
max
(KBr)/cmϪ1 1603 (C᎐O), 1676 (C᎐O).
᎐
᎐
23: (79%); mp 40 ЊC (from methanol); m/z 530, 532, 534
(1:2:1); δH(CDCl3); 4.01 (6H, s, 2 × OCH3), 4.54 (4H, s,
2 × CH2), 6.93 (2H, d, J 8.4 Hz, Hf), 7.42 (2H, s, Hd), 7.51 (2H,
d, J 8.4 Hz, He), 7.53 (1H, t, J 7.6 Hz, Hc), 8.00 (2H, d, J 7.6 Hz,
Hb), 8.14 (1H, s, Ha); δC(CDCl3) (normal/DEPT-135) 32.64
(Ϫve, CH2), 55.63 (ϩve, OMe), 111.80 (ϩve, ArCH), 127.89
(ab, ArC), 128.27 (ϩve, ArCH), 130.03 (ϩve, ArCH), 130.77
(ab, ArC), 131.02 (ϩve, ArCH), 133.05 (ϩve, ArCH), 134.59
(ϩve, ArCH), 137.63 (ab, ArC), 157.18 (ab, ArC), 194.59 (ab,
C᎐O); νmax(KBr)/cmϪ1 1601 (C᎐O), 1707 (CO) (Found: C, 53.8;
᎐
᎐
᎐
(C᎐O).
᎐
21: (17%); thick liquid; m/z 286 (Mϩ, 100%); δH(CDCl3) 2.34
(3H, s, CH3), 3.66 (3H, s, OCH3), 3.92 (3H, s, CO2CH3), 6.87
(1H, d, J 8.4 Hz, ArH), 7.20 (1H, s, ArH), 7.27 (1H, d, J 7.8 Hz,
ArH), 7.50 (1H, t, J 7.8 Hz, ArH), 7.98 (1H, d, J 7.8 Hz, ArH),
8.20 (1H, d, J 7.8 Hz, ArH), 8.39 (1H, s, ArH); δC (CDCl3) 20.40
(ϩve, CH3), 52.16 (ϩve, OCH3), 55.55 (ϩve, OCH3), 111.54
(ϩve, ArCH), 118.45 (ϩve, ArCH), 127.65 (ab, ArC), 128.24
(ϩve, ArCH), 130.19 (ϩve, ArCh), 130.29 (ϩve, ArCh), 132.45
(ϩve, ArCH), 133.56 (ab, ArC), 137.49 (ϩve, ArCH), 137.62
(ab, ArC), 155.48 (ab, ArC), 161.48 (ab, ArC), 166.23 (ab,
C᎐O), 195.27 (ab, C᎐O); νmax(KBr)/cmϪ1 1640, (C᎐O), 1670
᎐
᎐
H, 3.5. C24H20Br2O4 requires C, 54.13; H, 3.76%).
Synthesis of heterocalix[4]arenes 11–19, 24, 25. General
procedure
A suspension of 4a (2.66 g, 0.005 mol) in acetonitrile (800 ml)
containing benzimidazol-2(1H)-one (0.67 g, 0.005 mol), K2CO3
(10 g) and TBAHSO4 (50 mg) was heated to reflux and progress
of reaction was monitored by TLC. After completion of reac-
tion, K2CO3 was filtered off and washed with acetonitrile. The
filtrate and washings were combined, the solvent was distilled
off, and the residue was subjected to column chromatography
by using ethyl acetate–chloroform (20:80) as eluent to isolate
product 11. Similarly, reactions of 4a with 5-nitrobenzimidazol-
2(1H)-one 7, 5,6-dinitrobenzimidazol-2(1H)-one 8, uracil 9
and quinazole-2,4(1H,3H)-dione 10 provided the respective
heterocalix[4]arenes 13, 14, 16 and 18, respectively. The reac-
tions of 4b with heterocycles 6, 9 and 10 provided heterocalix-
᎐
᎐
᎐
(C᎐O).
᎐
22: (28%); mp 80 ЊC (from ethyl acetate); m/z 374 (Mϩ);
δH(CDCl3) 2.33 (6H, s, 2 × CH3), 3.65 (6H, s, 2 × OCH3), 6.84
(2H, d, J 8.2 Hz, ArH), 7.17 (2H, s, ArH), 7.23 (2H, d, J 8.2 Hz,
ArH), 7.47 (1H, t, J 7.6 Hz, ArH), 7.94 (2H, d, J 7.6 Hz, ArH),
8.17 (1H, s, ArH); δC(CDCl3) (normal/DEPT-135) 20.42
(ϩve, Me), 55.60 (ϩve, OMe), 111.62 (ϩve, ArH), 127.99 (ϩve,
ArCH), 128.35 (ab, ArC), 130.04 (ab, ArC), 130.19 (ϩve,
ArCH), 130.90 (ϩve, ArCH), 132.68 (ϩve, ArCH), 133.48
(ϩve, ArCH), 138.24 (ab, ArC), 155.45 (ab, ArC), 195.39 (ab,
C᎐O); νmax(KBr)/cmϪ1 1650 (C᎐O), 1672 (C᎐O) (Found: C,
᎐
᎐
᎐
77.5; H, 5.5. C24H22O4 requires C, 77.01; H, 5.88%).
J. Chem. Soc., Perkin Trans. 1, 2000, 1037–1043
1041

View Online
arenes 12, 17 and 19; 5a with 8 gave 15; and 23 with 6 and 9 gave
24 and 25, respectively.
(ab, C), 155.07 (ab, C), 159.67 (ab, C᎐O), 195.25 (ab, C᎐O);
᎐ ᎐
νmax(KBr)/cmϪ1 1699 (C᎐O), 1648 (C᎐O) (Found: C, 68.7; H,
᎐
᎐
11: (70%) (30 h); mp 352–354 ЊC (from CHCl3 ϩ C6H6); m/z
504 (Mϩ); δH(CDCl3) 4.05 (6H, s, 2 × OCH3), 5.10 (4H, br s,
2 × NCH2), 7.02–7.08 (6H, m, 2 × Hf, 2 × Hg, 2 × Hh),
7.29 (1H, br s, Ha), 7.54 (1H, t, J 7.6 Hz, Hc), 7.75 (2H, br s,
2 × Hd), 7.77 (2H, d, J 7.6 Hz, Hb), 8.03 (2H, dd, J1 8.6, J2 2.0
Hz, 2 × He); δC(CDCl3) (normal/DEPT-135) 37.28 (Ϫve,
NCH2), 55.98 (ϩve, OCH3), 108.22 (ϩve, ArCH), 111.36
(ϩve, ArCH), 121.44 (ϩve, ArCH), 124.89 (ab, ArC), 125.27
(ϩve, ArCH), 128.91 (ab, ArC), 129.56 (ab, ArC),
130.41 (ϩve, ArCH), 131.17 (ϩve, ArCH), 131.77 (ϩve, ArCH),
6.3; N, 7.5. C45H50N4O9 requires C, 68.35; H, 6.33; N, 7.09%).
16: (60%) (30 h); mp 333–335 ЊC (from CHCl3 ϩ C6H6); m/z
482 (Mϩ, 8.4%); δH(CDCl3 ϩ TFA) 3.98 (3H, s, OCH3), 4.01
(3H, s, OCH3), 4.52 (1H, br s, NCH2), 5.05 (1H, br s, NCH2),
5.42 (2H, br s, 2 × NCH2), 6.15 (1H, d, J 7.0 Hz, Hg), 7.09 (1H,
d, J 8.4 Hz, Hf/fЈ), 7.13 (1H, d, J 8.4 Hz, HfЈ/f), 7.41 (2H, br s,
HdЈ), 7.46 (1H, s, Ha), 7.59 (1H, d, J 7.0 Hz, Hh), 7.78 (1H,
t, J 6.4 Hz, Hc), 8.01–8.10 (4H, m, Hb, HbЈ, He and HeЈ);
δC(CDCl3 ϩ TFA) (normal/DEPT-135) 40.20 (Ϫve, NCH2),
48.89 (Ϫve, NCH2), 56.04 (ϩve, OCH3), 56.22 (ϩve, OCH3),
101.69 (ϩve, UC-5), 112.05 (ϩve, ArCH), 112.10 (ϩve, ArCH),
128.48 (ϩve, ArCH), 129.12 (ab, ArC), 130.84 (ϩve, ArCH),
132.86 (ϩve, ArCH), 133.24 (ϩve, ArCH), 134.30 (ϩve,
ArCH), 134.70 (ϩve, ArCH), 137.63 (ab, ArC), 138.14 (ab,
ArC), 145.96 (ϩve, UC-6), 151.78 (ab, C᎐O), 166.45 (ab, C᎐O),
132.73 (ϩve, ArCH), 139.21 (ab, ArC), 160.54 (ab, C᎐O),
᎐
195.78 (ab, C᎐O); νmax(KBr)/cmϪ1 1699 (C᎐O), 1648 (C᎐O)
᎐
᎐
᎐
(Found: C, 73.8; H, 4.5; N, 5.7%. C31H24N2O5 requires C, 73.81;
H, 4.76; N, 5.56%).
12: (45%) (30 h); mp 299 ЊC (from CHCl3); m/z 505 (Mϩ,
10%); δH(CDCl3) 4.05 (6H, s, 2 × OCH3), 4.95 and 5.27 (4H,
AB quartet, J 16.0 Hz, 2 × NCH2), 6.96 (4H, s, 2 × Hg, 2 × Hh),
7.05 (2H, d, J 8.6 Hz, 2 × Hf), 7.41 (2H, d, J 2.1 Hz, 2 × Hd),
7.53 (2H, d, J 7.6 Hz, 2 × Hb), 7.87 (1H, t, J 7.6 Hz, Hc), 8.11
(2H, dd, J1 8.6, J2 2.1 Hz, 2 × He); δC(CDCl3) (normal/DEPT-
135) 37.12 (Ϫve, NCH2), 55.96 (ϩve, OCH3), 108.00 (ϩve,
ArCH), 111.14 (ϩve, ArCH), 121.40 (ϩve, ArCH), 123.50 (ϩve,
ArCH), 124.63 (ab, ArC), 128.71 (ab, ArC), 129.12 (ab, ArC),
130.84 (ϩve, ArCH), 133.01 (ϩve, ArCH), 137.52 (ϩve, ArCH),
᎐
᎐
᎐
200.57 (ab, C᎐O); νmax(KBr)/cmϪ1 1715 (C᎐O), 1670 (C᎐O)
᎐
᎐
(Found: C, 70.0; H, 4.5, N, 5.4. C28H22N2O6 requires C, 69.71;
H, 4.56; N, 5.81%).
17: (40%) (30 h); mp 335 ЊC (from CHCl3 ϩ CH3OH); m/z
483 (Mϩ); δH(CDCl3 ϩ TFA) 3.98 (3H, s, OCH3), 4.02 (3H, s,
OCH3), 4.69, 5.34 (2H, AB quartet, J 14.0 Hz, NCH2), 4.94
and 5.49 (2H, AB quartet, J 14.0 Hz, NCH2), 6.07 (1H, d, J 7.8
Hz, Hg), 7.10 (1H, d, J 7.8 Hz, Hf/fЈ), 7.12 (1H, d, J 7.8
Hz, HfЈ/f), 7.41 (1H, br s, Hd/dЈ), 7.48 (1H, br s, HdЈ/d), 7.58 (1H,
d, J 7.8 Hz, Hh), 8.11–8.17 (4H, m, Hb, HbЈ, He, HeЈ), 8.54 (1H,
m, Hc); δC(CDCl3 ϩ TFA) (normal/DEPT-135) 33.22 (Ϫve,
NCH2), 42.27 (Ϫve, NCH2), 55.99 (ϩve, OCH3), 56.10 (ϩve,
OCH3), 101.17 (ϩve, UC-5), 111.54 (ϩve, ArCH), 123.18 (ab,
ArC), 125.14 (ϩve, ArCH), 125.42 (ϩve, ArCH), 127.69 (ab,
ArC), 128.45 (ab, ArC), 130.44 (ϩve, ArCH), 130.70 (ϩve,
ArCH), 131.37 (ϩve, ArCH), 132.00 (ϩve, ArCH), 139.44 (ϩve,
ArCH), 144.40 (ϩve, UC-6), 151.15 (ab, ArC), 155.30 (ab, ArC),
154.30 (ab, ArC), 156.93 (absent, ArC), 160.88 (ab, C᎐O),
᎐
193.99 (ab, C᎐O); νmax(KBr)/cmϪ1 1709 (C᎐O), 1666 (C᎐O),
᎐
᎐
᎐
1601 (C᎐O) (Found: C, 7.16; H, 4.3; N, 8.5. C H N O
᎐
30 23
3
5
requires C, 71.29; H, 4.55; N, 8.31%).
13: (35%) (30 h); mp >355 ЊC (from CHCl3 ϩ C6H6); m/z
549 (Mϩ); δH(CDCl3 ϩ TFA) 4.13 (3H, s, OCH3), 4.18 (3H, s,
OCH3), 5.28 (4H, s, 2 × NCH2), 7.15 (2H, d, J 9.0 Hz, Hf, HfЈ),
7.31 (1H, s, Ha), 7.42 (1H, d, J 8.8 Hz, Hi), 7.74 (1H, t, J 7.8 Hz,
Hc), 7.82 (2H, br s, Hd, HdЈ), 7.96–8.10 (4H, m, Hb, HbЈ, He and
HeЈ), 8.20 (1H, d, J 8.8 Hz, Hh), 8.36 (1H, s, Hg); δC(CDCl3
ϩ TFA) (normal/DEPT-135) 38.40 (Ϫve, NCH2), 56.33 (ϩve,
OCH3), 106.48 (ϩve, ArCH), 109.72 (ϩve, ArCH), 112.70
(ϩve, ArCH), 120.24 (absent, C), 124.31 (ab, C), 127.25 (ϩve,
ArCH), 128.82 (ab, C), 129.44 (ab, C), 129.53 (ab, C), 130.75
(ϩve, ArCH), 133.35 (ϩve, ArCH), 133.54 (ϩve, ArCH), 134.28
(ab, C), 138.37 (ab, C), 138.46 (ab, C), 143.50 (ab, C), 162.68
156.00 (ab, ArC), 161.51 (ab, C), 162.42 (ab, C᎐O), 164.92 (ab,
᎐
C᎐O), 193.92 (ab, C᎐O), 194.10 (ab, C᎐O); νmax(KBr)/cmϪ1 1717
᎐
᎐
᎐
(C᎐O), 1668 (C᎐O), 1602 (C᎐O) (Found: C, 67.2; H, 4.1; N, 8.9.
᎐
᎐
᎐
C27H21N3O6 requires C, 67.08; H, 4.35; N, 8.70%).
18: (65%) (30 h); mp 337–339 ЊC (from CHCl3 ϩ CH3OH);
m/z 532 (Mϩ, 15.8%); δH(CDCl3 ϩ TFA) 4.05 (3H, s, OCH3),
4.09 (3H, s, OCH3), 5.00 and 5.85 (2H, AB quartet, J 1.82 Hz,
NCH2), 5.26 and 5.55 (2H, AB quartet, J 18.0 Hz, NCH2), 6.93
(1H, d, J 1.3 Hz, Hd/dЈ), 7.01 (1H, d, J 1.3 Hz, HdЈ/dЈ), 7.12–7.22
(3H, m, Hf, HfЈ and Hj), 7.40 (1H, t, J 7.4 Hz, Hi), 7.49 (1H, s,
Ha), 7.58 (1H, t, J 7.6 Hz, Hc), 7.74 (1H, t, J 7.4 Hz, Hh), 7.83–
7.87 (2H, m, Hb and HbЈ), 8.11–8.24 (3H, m, He, HeЈ and Hg);
δC(CDCl3 ϩ TFA) (normal/DEPT-135) 40.79 (Ϫve, NCH2),
43.56 (Ϫve, NCH2), 56.17 (ϩve, OCH3), 56.76 (ϩve, OCH3),
111.89 (ϩve, CH), 111.98 (ϩve, CH), 114.48 (ab, C), 114.75
(ϩve, CH), 122.29 (ab, C), 123.60 (ab, C), 125.50 (ϩve, CH),
127.54 (ϩve, CH), 127.68 (ϩve, CH), 127.94 (ϩve, CH), 128.30
(ab, C), 128.43 (ab, C), 129.63 (ϩve, CH), 130.45 (ϩve, CH),
132.41 (ϩve, CH), 132.96 (ϩve, CH), 133.61 (ϩve, CH), 133.87
(ϩve, CH), 137.11 (ab, C), 137.65 (ϩve, CH), 138.10 (ab, C),
139.72 (ab, C), 151.15 (ab, C), 162.63 (ab, C), 162.83 (ab, C),
(ab, C), 162.79 (ab, C), 201.12 (ab, C᎐O); νmax(KBr)/cmϪ1 1650
᎐
(C᎐O), 1726 (C᎐O) (Found: C, 67.1; H, 4.3; N, 7.5. C H N O
᎐
᎐
31 23
3
7
requires C, 67.76; H, 4.19; N, 7.65%).
14: (45%) (30 h); mp >355 ЊC (from CHCl3 ϩ C6H6); m/z 594
(Mϩ); (CDCl3 ϩ TFA) 4.14 (6H, s, 2 × OCH3), 5.30 (4H, s,
2 × NCH2), 7.17 (2H, d, J 8.8 Hz, 2 × ArH), 7.81 (1H, t, J 7.8
Hz, ArH), 7.98–8.10 (9H, m, 9 × ArCH); δC(CDCl3 ϩ TFA)
(normal/DEPT-135) 36.22 (Ϫve, NCH2), 58.31 (ϩve, OCH3),
106.73 (ϩve, ARCH), 112.49 (ϩve, ArCH), 123.40 (ab, C),
127.48 (ϩve, ArCH), 129.84 (ab, C), 130.85 (ϩve, ArCH),
133.27 (ϩve, ArCH), 134.00 (ϩve, ArCH), 134.40 (ϩve,
ArCH), 138.05 (ab, C), 139.01 (ab, C), 155.73 (ab, C), 161.46 (ab,
C᎐O), 199.63 (ab, C᎐O); νmax(KBr)/cmϪ1 1652 (C᎐O), 1725
᎐
᎐
᎐
(C᎐O) (Found: C, 62.7; H, 3.5; N, 9.1. C H N O requires C,
62.62; H, 3.70; N, 9.42%).
164.10 (ab, C), 199.50 (ab, C᎐O), 200.28 (ab, C᎐O); νmax(KBr/
᎐ ᎐
᎐
31 22
4
9
cmϪ1 1705 (C᎐O), 1650 (C᎐O) (Found: C, 72.1; H, 4.1.
᎐ ᎐
15: (12%) (30 h); mp 319–320 ЊC (from CHCl3 ϩ MeOH);
791 (Mϩ ϩ 1); m/z (ES) δH(CDCl3) 0.90 (6h, t, J 6.6 Hz,
2 × CH3), 1.26–1.60 (20H, m, 10 × CH2), 2.03 (4H, q, J 7.0 Hz,
2 × CH2), 4.21 (4H, br s, 2 × OCH2), 5.20 (4H, s, 2 × NCH2),
7.06 (2H, d, J 8.6 Hz, 2 × ArH), 7.28 (1H, s, ArCH), 7.75
(1H, t, J 7.6 Hz, ArH), 7.88 (2H, s, 2 × ArCH), 7.95–8.01
(6H, m, 6 × ArCH); δC(CDCl3) (normal/DEPT-135) 14.05
(ϩve, CH3), 22.63 (Ϫve, CH2), 26.04 (Ϫve, CH2), 29.16 (Ϫve,
CH2), 29.34 (Ϫve, CH2), 31.78 (Ϫve, CH2), 37.73 (Ϫve, NCH2),
69.53 (Ϫve, OCH2), 105.32 (ϩve, ArCH), 112.75 (ϩve, ArCH),
123.20 (ab, C), 126.14 (ϩve, ArCH), 130.09 (ϩve, ArCH),
130.85 (ab, C), 130.94 (ab, C), 132.42 (ϩve, ArCH), 133.09
(ϩve, ArCH), 133.47 (ϩve, ArCH), 138.68 (ab, C), 138.88
C32H24N2O6 requires C, 72.18; H, 4.51%).
19: (45%); mp 320 ЊC (from CHCl3 ϩ CH3OH); m/z 533
(Mϩ); δH(CDCl3 ϩ TFA) 4.07 (3H, s, OCH3), 4.10 (3H, s,
OCH3), 5.02 and 5.77 (2H, AB quartet, J 18.0 Hz, NCH2), 5.19
and 5.56 (2H, AB quartet, J 16.6 Hz, NCH2), 6.88 (2H, d,
J 10.8 Hz, 2 × ArH), 7.08–7.24 (3H, m, 3 × ArH), 7.38 (1H, t,
J 7.6 Hz, ArH), 7.71 (1H, t, J 7.4 Hz, ArH), 7.88 (2H, d, J 7.8
Hz, 2 × ArH), 8.15–8.32 (4H, m, 4 × ArH); δC(CDCl3 ϩ TFA)
(normal/DEPT-135) 40.31 (Ϫve, NCH2), 42.60 (Ϫve, NCH2),
56.15 (ϩve, OCH3), 111.71 (ϩve, CH), 114.37 (ab, C), 114.53
(ϩve, CH), 122.25 (ab, C), 123.72 (ab, C), 124.37 (ϩve, CH),
124.94 (ϩve, CH), 125.00 (ab, C), 127.16 (ab, C), 127.55 (ab, C),
128.08 (ϩve, CH), 128.79 (ϩve, CH), 129.15 (ϩve, CH), 131.16
1042
J. Chem. Soc., Perkin Trans. 1, 2000, 1037–1043

View Online
(ϩve, CH), 131.77 (ϩve, CH), 136.56 (ϩve, CH), 139.26 (ab,
C), 140.02 (ϩve, CH), 150.55 (ab, C), 154.44 (ab, C), 155.14 (ab,
The weighting scheme used was
1
C), 162.31 (ab, C᎐O), 162.68 (ab, C᎐O), 192.82 (ab, C᎐O),
᎐
᎐
᎐
᎐
w =
[σ2Fo2 ϩ (0.1414P)2 ϩ 4.63P]
193.40 (ab, C᎐O); νmax(KBr)/cmϪ1 1707 (C᎐O), 1665 (C᎐O),
᎐
᎐
1601 (C᎐O) (Found: C, 69.9; H, 3.8; N, 7.5. C H N O
requires C, 69.79; H, 4.32; N, 7.88%).
where P = [Fo2 ϩ 2Fc2]/3
᎐
31 23
3
6
24: (33%); mp 240 ЊC (from AcOH); m/z 504 (Mϩ);
δH(TFA ϩ CDCl3) 3.75 (6H, s, 2 × OCH3), 5.06 (4H, br s,
2 × CH2), 6.94 (2H, d, J 8 Hz, Hf), 7.08 (2H, s, Hd), 7.27–7.30
(4H, m, benzimid.-H), 7.45 (1H, s, Ha), 7.57 (2H, d, J 8.0 Hz,
He), 7.73 (1H, t, J 7.6 Hz, Hc), 8.32 (2H, d, J 7.6 Hz, Hb);
δC(TFA ϩ CDCl3) (normal/DEPT-135) 44.71 (Ϫve, CH2),
55.58 (ϩve, OCH3), 109.79 (ϩve, CH), 112.07 (ϩve, CH),
112.62 (ϩve, CH), 124.55 (ϩve, CH), 126.79 (ab, C), 128.16
(ϩve, ArCH), 129.09 (ab, C), 129.49 (ab, C), 132.56 (ab, C),
134.62 (ϩve, ArCH), 135.36 (ϩve, CH), 136.55 (ϩve, CH),
A final refinement11 of 397 parameters with six restraints
gave R = 0.0717, wR = 0.1967 for observed reflections and
R = 0.1286, wR = 0.2484 for all reflections.
Acknowledgements
We thank UGC and DST, New Delhi for financial assistance.
References
137.37 (ab, C), 159.57 (ab, C), 208.92 (ab, C᎐O); νmax(KBr)/cmϪ1
1 Heterocalixarenes Parts 1 and 2, see (a) S. Kumar, G. Hundal,
D. Paul, M. S. Hundal and H. Singh, J. Org. Chem., 1999, 64,
7717; (b) S. Kumar, D. Paul and H. Singh, J. Inclusion Phenom.
Mol. Recognit., 1999, in press.
᎐
1700 (C᎐O), 1665 (C᎐O) (Found: C, 73.5; H, 4.5; N, 5.3.
᎐
᎐
C31H24N2O5 requires C, 73.81; H, 4.76; N, 5.56%).
25: (10%); mp 280 ЊC (from chloroform ϩ ethanol); m/z 482
(Mϩ); δH(CDCl3) 3.75 (6H, s, 2 × OCH3), 4.69 (2H, s, NCH2),
4.97 (2H, s, NCH2), 5.80 (1H, d, J 7.8 Hz, U5-H), 6.86 (1H, d,
J 8.2 Hz, Hf/fЈ), 6.89 (1H, d, J 8.2 Hz, HfЈ/f), 7.26 (1H, d, J 8.2
Hz, HeЈ/e), 7.35 (1H, d, J 7.8 Hz, U6-H), 7.44 (3H, s, Ha, Hd,
HdЈ), 7.69 (1H, d, J 8.2 Hz, He/eЈ), 7.74 (1H, t, J 7.8 Hz, Hc),
8.42 (2H, d, J 7.8 Hz, Hb/bЈ); δC(CDCl3) (normal/DEPT-135)
42.80 (Ϫve, CH2), 53.62 (Ϫve, CH2), 101.67 (ϩve, UC-5),
111.90 (ϩve, ArH), 112.06 (ab, ArC), 126.34 (ab, ArC), 127.04
(ab, ArC), 127.97 (ab, ArC), 128.16 (ab, ArC), 129.45 (ab, ArC),
130.37 (ϩve, ArCH), 130.80 (ϩve, ArCH), 131.80 (ϩve,
ArCH), 133.91 (ϩve, ArCH), 134.61 (ϩve, ArCH), 134.64
(ϩve, ArCH), 137.34 (ab, ArC), 137.83 (ab, ArC), 141.95 (ϩve,
UC-6), 150.27 (ab, ArC), 157.61 (ab, ArC), 162.74 (ab, ArC),
2 (a) C. D. Gutsche, Calixarenes, Monographs in Supramolecular
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175.92 (ab, C᎐O), 194.06 (ab, C᎐O), 205.35 (ab, C᎐O), 216.80
᎐
᎐
᎐
(ab, C᎐O); νmax(KBr)/cmϪ1 1675, 1660, 1708 (C᎐O) (Found: C,
᎐
᎐
70.1; H, 4.4; N, 5.7. C28H22N2O6 requires C, 69.71; H, 4.56; N,
5.81%).
X-Ray structure analysis of 11–benzene complex†
4 (a) G. Satori, R. Maggi, F. Bigi, A. Arduini, A. Pastorio and
C. Porta, J. Chem. Soc., Perkin Trans. 1, 1994, 1657; (b) S. E. Biali,
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A. Postorio, M. A. Pellinghelli, F. Peri, C. Porta and G. Sartori,
Tetrahedron, 1997, 53, 13037; (d) K. Ro, S. Izawa, T. Ohba, Y. Ohba
and T. Sone, Tetrahedron Lett., 1996, 37, 5959.
5 (a) A. A. Moshfegh, R. Badri, M. Hojjatie, M. Kaviani, B. Naderi,
A. H. Nazmi, M. Ramezanian, B. Roozpeikar and G. H.
Hakimelahi, Helv. Chim. Acta, 1982, 65, 1221; (b) A. A. Moshfegh,
F. Beladi, A. S. Hasseini, S. Tofigh and G. H. Hakimelahi,
Helv. Chim. Acta, 1982, 65, 1264; (c) A. Ninagawa, K. Cho and
H. Matsuda, Makromol. Chem., 1985, 186, 1397; (d) G. Gormer,
K. Seiffarth and M. Schylz, Makromol. Chem., 1990, 191, 81.
6 (a) P. Timmermman, S. Harkema, G. J. V. Hummel, W. Verboom
and D. N. Reinhoudt, J. Inclusion Phenom. Mol. Recognit., 1993, 16,
189; (b) F. Ugozzoli and G. D. Andreetti, J. Inclusion Phenom. Mol.
Recognit., 1992, 13, 337.
7 The energy-minimization studies have been performed by using
PCMODEL, provided by Serena Software.
8 S. Kumar, M. S. Hundal, G. Hundal, P. Singh, V. Bhalla and
H. Singh, J. Chem. Soc., Perkin Trans. 2, 1998, 925.
9 L. S. Efros and A. V. El’tsov, Zh. Obsch. Khim., 1957, 27, 127 (Chem.
Abstr., 1957, 51, 12882h).
10 G. M. Sheldrick, SHELXTL-PC Version 5.03, Siemens Analytical
Instruments Inc., Madison, WI, 1995.
11 XSCAN: Siemens X-ray Single Crystal Analysis System Software
Package, version 2.1, Siemens Analytical Instruments Inc.,
Madison, WI.
Crystals of 11–benzene were obtained by slow evaporation from
chloroform–benzene (1:1 v/v) mixture. All intensity-data meas-
urements were carried out at room temperature on a Siemens
P4 four-circle diffractometer with graphite-monochromatized
MoKα radiation (λ = 0.7169 Å). The crystals with molecular
formula C37H30N2O5 and relative molecular mass 582.63
belonged to the monoclinic septum, C2/c space group with
a = 35.636(4), b = 9.226(1), c = 17.779(2) Å, V = 5839.1 (11) Å3
Z = 8. A total of 3885 reflections were collected, out of which
3814 were independent (Rint = 0.0239) and 2245 were observed
[I > 2σ(I)]. The data were corrected for Lorentz and polariz-
ation effects. No absorption correction was applied.
The structure was solved by direct methods using
SHELXTL-PC.10 A full matrix least-squares refinement on F2,
with anisotropic thermal parameters for all the non-hydrogen
atoms, showed disorder in the benzene molecule, as inferred
from the short C–C distances and high thermal parameters
of three carbons [C(35) to C(37)]. In the initial stages of
refinement the benzene molecule [C(32)–C(37)] was refined as a
rigid group. At final stages of the refinement it was made free
but C–C distances were fixed at 1.390(3) Å. No attempt was
made to resolve the disordered atoms. All the hydrogens were
fixed geometrically and made to ride on their respective atoms.
† CCDC reference number 207/395. See http://www.rsc.org/suppdata/
p1/a9/a906883/ for crystallographic files in .cif format.
Paper a906883j
J. Chem. Soc., Perkin Trans. 1, 2000, 1037–1043
1043