Upper rim substitution of calix[4]arenes via their upper rim A,C dinitro compounds

Full text of DOI:10.1021/jo980903z

998
J . Org. Chem. 1999, 64, 998-1003
the “deep pocket” imines 12a -d , and the intramolecu-
Up p er Rim Su bstitu tion of Ca lix[4]a r en es
larly bridged compounds 6a -c, 7a -c, and 8a -d .
via Th eir Up p er Rim A,C Din itr o
Com p ou n d s1
The building of upper rim bridged and deep pocket
calixarenes is of particular interest to a program in this
laboratory involving calixarenes as catalysts.8 Treatment
of 2a -c with diacid chlorides containing four or more
methylene groups separating the chlorocarbonyl moieties
resulted in intramolecular bridging to yield 6a -c from
2a , 7a -c from 2b, and 8a -d from 2c, as shown in Figure
2. The shorter succinoyl dichloride, however, failed to
bridge the amino groups and, instead, gave 9 (after
ethanolysis of the intially formed diacid chloride) which
was also prepared by treatment with ethyl succinoyl
monochloride. Similarly, terphthaloyl dichloride yielded
10 (after hydrolysis of the initially formed diacid chloride)
(for structures, see Chart 1). A reaction reciprocally
related to the conversion of 2c to 10 has been reported
Shiv Kumar Sharma and C. David Gutsche*
Department of Chemistry, Texas Christian University,
Fort Worth, Texas 76129
Received May 11, 1998 (Revised Manuscript Received November
16, 1998 )
p-tert-Butylcalix[4]arene, easily accessible via base-
induced condensation of p-tert-butylphenol and formal-
dehyde,2 provides a convenient starting material for the
preparation of calixarenes3 carrying a wide variety of
groups on both the upper and lower rims. An earlier
publication4 in this series detailed the preparation of
upper rim 5,17-substituted calix[4]arenes and described
their use in the selective introduction of lower rim groups
which established conformational immobility. In the
present paper the focus shifts to the upper rim of these
compounds, employing the nitro groups as precursors to
amino groups and various functionalities derived there-
from.
Although p-tetranitrocalix[4]arene5 as well as its alkyl
ethers are effectively reduced to the corresponding tet-
raamines6 with SnCl2, this reagent failed with the 5,17-
dinitro compounds 1a -c, probably because of their
limited solubility. With Raney Ni and NH2NH2 in EtOAc,7
however, smooth reduction occurs to afford the diamines
2a -c. As shown in Figure 1, these in turn have been
converted to a variety of amides 3a -h (O-dealkylation
of 3a -c yields the calix[4]arenetetrols 5a from 3a -c, 5b
from 3d -f, and 5c from 2a -c), p-toluenesulfonamide 4,
by J ørgensen and co-workers9 in which
a
5,17-
bischlorocarbonylcalix[4]arene was treated with p-phen-
ylenediamine. In this case only intermolecularly bridged
compounds were isolated, the biscalix[4]arene in 19.5%
yield along with much smaller amounts of higher oligo-
mers including a trace of the tetrakiscalix[4]arene.
Compounds 3d ,f,g, 4, and 10 might be considered as
members of the deep pocket family of calixrenes in which
substituents of significant bulk occupy the upper rim, as
also are the imines 11a -d and 12a ,b obtained by
reaction of 2c with aromatic aldehydes and ketones.
Exp er im en ta l Section 10
5,17-Bisa m in o-25,26,27,28-t et r a k is(b en zyloxy)ca lix[4]-
a r en e (2a ) (Con e Con for m er ). A 1.0-g sample of Raney nickel
was added to a solution of 8.80 g (10 mmol) of 5,17-bisnitro-
25,26,27,28-tetrakis(benzyloxy)calix[4]arene (1a ) in 200 mL of
EtOAc. MeOH (150 mL) was added followed by 30 mL of
NH2NH2‚H2O in portions at room temperature with occasional
stirring. The reaction mixture was refluxed 5 h, another 20 mL
of NH2NH2‚H2O was added, and the mixture was refluxed
another 6 h. It was filtered, and the residue was washed with
CH2Cl2 and Me2CO. The combined filtrate was concentrated
under reduced pressure and poured dropwise over ice cold water
with stirring to give a white precipitate (turned to light brown
on exposure to air) which was removed by filtration, dried, and
trituarated with MeOH to give 6.2 g (76%) of 2a : mp 210-211
(1) Paper no. 50 in a series entitled Calixarenes. For paper no. 49
cf.: Xie, D.; Gutsche, C. D. J . Org. Chem. 1999, 64, 9270.
(2) Gutsche, C. D.; Iqbal, M. Org. Synth. 1990, 68, 234.
(3) (a) Gutsche, C. D. Calixarenes Revisited. In Monographs in
Supramolecular Chemistry; Stoddart, J . F., Ed.; Royal Society of
Chemistry: London, 1998. (b) Bo¨hmer, V. Calixarenes, Macrocycles
with (Almost) Unlimited Possibilties. Angew. Chem., Int. Ed. Engl.
1995, 34, 713-745. (c) Gutsche, C. D. Calixarenes. Aldrichimica Acta
1995, 28, 3-9. (d) Calixarenes, A Versatile Class of Macrocyclic
Compounds; Vicens, J ., Bo¨hmer, V., Eds.; Kluwer: Dordrecht, The
Netherlands, 1991. (e) Gutsche, C. D. Calixarenes. In Monographs in
Supramolecular Chemistry; Stoddart, J . F., Ed.; Royal Society of
Chemistry: London, 1989.
(4) Sharma, S. K.; Gutsche, C. D. J . Org. Chem. 1996, 61, 2564.
(5) Zhang, W.-C.; Zheng, Y.-S.; Huang, Z.-T. Synthetic Commun.
1997, 27, 3763 have described a nitration procedure using KNO3 and
AlCl3 in MeCN at 0 °C that is stated to give pure p-nitrocalix[4]arene,
p-nitrocalix[6]arene, and p-nitrocalix[8]arene in yields of 84, 89, and
84%, respectively. Attempts in our laboratories to reproduce these
results, however, have yielded mixtures in all cases, leading to
considerably lower yields of pure p-nitrocalix[4]arene in the first case
and to no isolable product in the other two cases. The procedure for
generating p-nitrocalix[4]arene and p-nitrocalix[8]arene were studied
under a variety of conditions in which the ratio of reactants, the
temperature, and the time of reaction were varied. Under none of these
conditions could the reported data be reproduced.
(8) Xie, D.; Gutsche, C. D. J . Org Chem. 1999, 64, 9270.
(9) J øorgensen, M.; Larsen, M.; Sommer-Larsen, P.; Petersen, W.
B.; Eggert, H. J . Chem. Soc., Perkin Trans. 1 1997, 2851.
(10) Unless otherwise noted, starting materials were obtained from
commercial suppliers and used without further purification. Dichlo-
romethane was used as HPLC-grade. Column chromatography was
carried out with Aldrich 70-230 mesh, 60-Å silica gel. Thin-layer
chromatography (TLC) was performed on 250-µm silica gel plates
containing a fluorescent indicator. Melting points were taken in sealed
and evacuated melting point capillary tubes on a MEL-Temp apparatus
(Laboratory Devices, Cambridge, MA) using a 400 °C thermometer
calibrated against a thermocouple and are uncorrected. The 1H and
13C NMR spectra were recorded on a Varian XL-300 spectrometer, and
the chemical shifts are reported as δ values with units of parts-per-
million (ppm). 1H NMR spectra are referenced to tetramethylsilane
(TMS) at 0.00 ppm as an internal standard and recorded at room
temperature (20 ( 1 °C), and 13C NMR spectra are referenced to either
CDCl3 (77.00 ppm), DMSO-d6 (40.0 ppm) or to TMS (0.00 ppm) and
also recorded at room temperature (20 ( 1 °C). Microanalytical samples
were dried for at least 48-72 h at 111 °C (toluene) or at 140 °C (xylene)
at 1-2 mm, and the analyses were carried out by Desert Laboratories,
Tucson, AZ. Solvent of crystallization was retained in some of the
analytical samples and affected the elemental analysis. In such cases,
best fits between the analytical values and appropriate increments of
the solvents were used.11
(6) (a) van Loon, J .-D.; Arduini, A.; Coppi, L.; Verboom, W.; Pochini,
A.; Ungaro, R.; Harkema, S.; Reinhoudt, D. N.J . Org. Chem. 1990, 55,
5639. (b) van Loon, J .-D.; Arduini, A.; Verboom, W.; Ungaro, R.; van
Hummel, G. J .; Harkema, S. Reinhoudt, D. N. Tetrahedron Lett. 1989,
30, 2681. (c) Verboom, W.; Durie, A.; Egberink, R. J . M.; Asfari, Z.;
Reinhoudt, D. N. J . Org. Chem. 1992, 57, 1313. (d) Timmerman, P.;
Verboom, W.; Reinhoudt, D. N.; Arduini, A.; Grandi, S.; Sicuri, A. R.;
Pochini, A.; Ungaro, R. Synthesis 1994, 185.
(7) Yang, X.; McBranch, D.; Swanson, B.; Li, DeQuan Angew. Chem.,
Int. Ed. Engl. 1996, 35, 538.
10.1021/jo980903z CCC: $18.00 © 1999 American Chemical Society
Published on Web 01/14/1999

Notes
J . Org. Chem., Vol. 64, No. 3, 1999 999
F igu r e 1. Synthesis and derivatization of 5,17-diaminocalix[4]arenes.
F igu r e 2. Upper rim bridged 5,17-diaminocalix[4]arenes.
°C; 1H NMR (CDCl3) δ 7.32-7.15 (m, 20), 6.58-6.56 (m, 6), 5.88
(s, 4), 4.91 (s, 4), 4.83 (s, 4), 4.13 (d, 4, J ) 13.5 Hz), 2.81 (d, 4,
J ) 13.5 Hz), 2.90 (bs, 4); 13C NMR (CDCl3) δ 155.91, 149.10,
141.13, 138.48, 138.28, 136.17, 135.84, 130.03, 128.73, 128.60,
128.39, 128.29, 128.11, 128.07, 122.51, 116.27, 76.87, 76.58,
31.84. Anal. Calcd for C56H50N2O4: C, 82.53; H, 6.18. Found C,
82.63; H, 6.26.
5,17-Bisa m in o-25,26,27,28-t et r a k is(b en zyloxy)ca lix[4]-
a r en e (2b) (1,3-Alter n a te Con for m er ). To a mixture of 1.0 g
of Raney nickel and 4.40 g (5 mmol) of 5,17-bisnitro-25,26,27,28-
tetrakis(benzyloxy)calix[4]arene (1b) in 100 mL of EtOAc and
50 mL of MeOH was added 50 mL of NH2NH2‚H2O in portions.
The reaction mixture was refluxed 10 h and then worked up as
described above for 2a to give 2.84 g (70%) of 2b: mp 212-214

1000 J . Org. Chem., Vol. 64, No. 3, 1999
Notes
Ch a r t 1
°C; 1H NMR (CDCl3) δ 7.55 (t, 4, J ) 7.5 Hz), 7.45-7.35 (m, 12),
7.20 (d, 4, J ) 6.6 Hz), 6.69 (d, 4, J ) 7.5 Hz), 6.48 (t, 2, J ) 7.2
Hz), 6.05 (s, 4), 4.93 (s, 4), 4.87 (s, 4), 3.58 (dd, 8, J ) 14.7 Hz),
2.82 (bs, 4); 13C NMR (CDCl3) δ 156.06, 148.99, 140.53, 139.33,
138.79, 134.71, 134.10, 131.60, 128.53, 128.38, 128.05, 127.12,
127.05, 126.83, 122.56, 118.69, 72.23, 71.52, 37.75. Anal. Calcd
for C56H50N2O4: C, 82.53; H, 6.18, N, 3.44. Found: C, 82.08; H,
6.21; N, 3.30.
128.15, 122.80, 121.64, 77.39, 76.14, 31.74, 24.49. Anal. Calcd
for C60H54N2O6‚H2O:11 C, 78.60; H, 5.90. Found: C, 78.58; H,
6.15.
Using the procedure described above for the preparation of
3a , the following compounds were synthesized.
5,17-Bis(N-a ceta m id o)-25,26,27,28-tetr a k is(ben zyloxy)-
ca lix[4]a r en e (3b) (1,3-a lter n a te con for m er ): yield, 86%; mp
255-257 °C; 1H NMR (CDCl3) δ 7.44-7.37 (m, 12), 7.24-7.12
(m, 18), 6.71 (s, 4), 6.69 (d, 4, J ) 7.5 Hz), 6.45 (t, 2, J ) 7.2 Hz),
6.13 (bs, 2), 4.82 (s, 8), 3.60 (s, 8), 1.96 (s, 6). Anal. Calcd for
C60H54N2O6‚1/2H2O:11 C, 79.05; H, 5.94. Found: C, 79.36; H, 6.10.
5,17-Bis(N-a ceta m id o)-26,28-d iben zyloxyca lix[4]a r en e-
26,28-d iol (3c) (con e con for m er ): yield, 80%; mp 285-286
5,17-Bisa m in o-26,28-d iben zyloxyca lix[4]a r en e-25,27-d i-
ol (2c) (Con e Con for m er ). To a mixture of 0.5 g of Raney nickel
and 3.50 g (5 mmol) of 5,17-bisnitro-26,28-dibenzyloxycalix[4]-
arene-25,27-diol (1c) in 100 mL of EtOAc and 100 mL of MeOH
was added 20 mL of NH2NH2‚H2O in portions. The reaction
mixture was refluxed 10 h and then worked up as described
above for 2a to give 2.28 g (72%) of 2c: mp 170 °C (softening),
246-250 °C; 1H NMR (CDCl3) δ 7.70-7.58 (m, 4), 7.34-7.32 (m,
6), 7.08 (s, 2), 6.86 (d, 4, J ) 7.5 Hz), 6.70 (t, 2, J ) 8.4 and 7.2
Hz), 6.44 (s, 4), 5.00 (s, 4), 4.25 (d, 4, J ) 13.2 Hz), 3.17 (d, 4, J
) 13.2 Hz), 3.20-2.90 (b, 4); 13C NMR (CDCl3) δ 152.33, 146.61,
138.31, 137.11, 133.65, 129.24, 129.01, 128.29, 127.95, 127.87,
125.53, 116.34, 78.56, 31.83.
1
°C; H NMR (CDCl3) δ 8.64 (s, 2), 7.83 (s, 2), 7.63-7.60 (m, 4),
7.41-7.36 (m, 6), 7.25 (s, 4), 6.96 (d, 4, J ) 7.8 Hz), 6.77 (t, 2, J
) 7.5 Hz), 5.09 (s, 4), 4.26 (d, 4, J ) 12.9 Hz), 3.39 (d, 4, J )
12.9 Hz), 2.08 (s, 6). Anal. Calcd for C46H42N2O6‚1/2H2O:11 C,
75.91; H, 5.95. Found: C, 75.78; H, 5.85.
5,17-Bis(N-ben za m id o)-25,26,27,28-tetr a k is(ben zyloxy)-
ca lix[4]a r en e (3d ) (con e con for m er ): yield, 82%; mp 282-
284 °C; 1H NMR (CDCl3) δ 7.66-7.60 (m 6), 7.35-7.19 (m, 24),
6.79 (s, 4), 6.71-6.70 (m, 6), 5.02 (s, 4), 4.87 (s, 4), 4.19 (d, 4, J
5,17-Bis(N-a ceta m id o)-25,26,27,28-tetr a k is(ben zyloxy)-
ca lix[4]a r en e (3a ) (Con e Con for m er ). A stirred solution of
0.21 g (0.25 mmol) of 2a in 20 mL of HPLC-grade CH2Cl2 was
treated with 0.5 mL of pyridine or triethylamine followed by 1.0
mL of acetyl chloride (vigorous reaction). The reaction mixture
was stirred at room temperature for 10 min, and another 10
mL of CH2Cl2 was added to reduce the viscosity. After 3 h of
standing at room temperature, the contents of the flask were
poured over ice-cold water and neutralized with 20% HCl to give
a white solid which was removed by filtraton and triturated with
n-hexane followed by MeOH to yield 0.20 g (90%) of 8a : mp 144-
146 (softening), 240-241 °C; 1H NMR (CDCl3) δ 7.31 (m, 20),
6.78 (bs, 6), 6.78-6.76 (m, 6), 6.34 (s, 4), 5.06 (s, 4), 4.75 (s, 4),
)
13.5 Hz), 2.93 (d, 4, J ) 13.8 Hz). Anal. Calcd for
C70H58N2O6: C, 82.17; H, 5.71. Found: C, 82.24; H, 5.85.
5,17-bis(N-ben za m id o)-25,26,27,28-tetr a k is(ben zyloxy)-
ca lix[4]a r en e (3e) (1,3-a lter n a te con for m er ): yield, 90%; mp
282-283 °C; 1H NMR (CDCl3) δ 7.66-7.53 (m, 6), 7.48-7.38 (m,
10), 7.21-7.15 (m, 12), 7.03-7.02 (m, 2), 6.92 (s, 4), 6.84 (s, 2),
6.69 (d, 4, J ) 7.5 Hz), 6.47 (t, 2, J ) 7.5 Hz), 4.86 (s, 8), 3.65 (s,
8). Anal. Calcd for C70H58N2O6: C, 82.17; H, 5.71. Found: C,
82.40; H, 5.64.
5,17-Bis(N-ben za m id o)-26,28-d iben zyloxyca lix[4]a r en e-
25,27-d iol (3f) (con e con for m er ): yield, 78%; mp 274-275 °C;
(11) The presence of a complexed water molecule was qualitatively
supported by the appearance of a broad signal in its 1H NMR spectrum.
A spectrum in CDCl3 alone showed a peak at δ 1.6 ppm and DMSO-d6
at δ 3.4 ppm.
4.15 (d, 4, J ) 13.5 Hz), 2.89 (d, 4, J ) 13.5 Hz), 1.93 (s, 6); 13
C
NMR (CDCl3) δ 168.67, 155.78, 152.76, 137.87, 136.47, 134.92,
131.88, 130.46, 129.56, 129.21, 128.99, 128.74, 128.60, 128.30,

Notes
J . Org. Chem., Vol. 64, No. 3, 1999 1001
1H NMR (CDCl3) δ 8.16 (d, 4, J ) 7.5 Hz), 7.86 (d, 4, J ) 6.9
Hz), 7.75 (s, 1), 7.68-7.62 (m, 6), 7.55-7.44 (m, 6), 7.40-7.39
(m, 6), 6.94 (d, 4, J ) 7.5 Hz), 6.74 (t, 2, J ) 7.5 Hz), 5.06 (s, 4),
4.31 (d, 4, J ) 13.2 Hz), 3.35 (d, 4, J ) 13.2 Hz). Anal. Calcd for
C56H46N2O6‚1/2H2O:11 C, 78.95; H, 5.56. Found: C, 79.17; H, 5.35.
5,17-Bis(N-[3,5-d in itr oben z]a m id o)-25,26,27,28-tetr a k is-
(ben zyloxy)ca lix[4]a r en e (3g) (con e con for m er ): yield, 51%;
mp 254-255 °C; 1H NMR (CDCl3) δ 8.94 (s, 2), 8.78 (bs, 4), 8.29
(s, 2), 7.34-7.18 (m, 20), 6.83-6.72 (m, 10), 5.09 (s, 4), 4.82 (s,
4), 4.19 (d, 4, J ) 13.5 Hz), 2.91 (d, 4, J ) 13.2 Hz). Anal. Calcd
for C70H54N6O14‚1/2H2O:11 C, 69.35; H, 4.57. Found: C, 69.19;
H, 4.52.
130.09, 129.03, 127.95, 123.69, 123.27, 120.96, 30.53. Compound
5c was converted to 5a (vide supra) to confirm its structure.
Br id ged Com p ou n d 6a (Con e Con for m er ). A 0.81-g (0.1
mmol) sample of 2a dissolved in 500 mL of HPLC-grade CH2Cl2
was placed in a 500-mL dropping funnel, and 0.40 g (0.15 mmol,
1.5 equiv) of sebacoyl chloride was dissolved in 250 mL of CH2Cl2
was placed in a 250-mL dropping funnel. To a stirred mixture
of 750 mL of CH2Cl2 and 0.5 mL of pyridine in a 3-L round-
bottomed flask at room temperature were added 10 mL from
the 500-mL funnel and 5 mL from the 250-mL funnel. This
addition procedure was repeated every 30 min over a period of
5 days. The reaction mixture was stirred an addtional 2 days,
and the solvent was removed under reduced pressure to leave a
brownish semisolid. This was triturated with n-hexane to leave
a light yellow material which was separated by filtration and
dissolved in MeOH. The hexane-soluble portion, consisting of
unreacted acid chloride and pyridine, was discarded. The hex-
ane-insoluble portion was again dissolved in a minimum amount
of CH2Cl2, poured over n-hexane to produce a light yellow
precipitate, filtered, and dried to give 0.82 g of solid. This was
dissolved in 100 mL of CH2Cl2 and treated with activated
charcoal to remove the color and then filtered, concentrated, and
passed through a silica gel column (eluted with 1:3 EtOAc-
CH2Cl2) to give 0.63 g (64%) of 6a as a white powder. An
analytical sample was obtained by triturating with n-hexane:
5,17-Bis(N-cyclop r op yla m id o)-26,28-d iben zyloxyca lix[4]-
a r en e-25,27-d iol (3h ) (con e con for m er ): yield, 67%; mp 290-
293 °C; 1H NMR (CDCl3 + DMSO-d6) δ 7.12 (s, 2), 7.79 (s, 2),
7.61 (bs, 4), 7.35 (bs, 6), 7.28 (s, 4), 6.95 (d, 4, J ) 5.4 Hz), 6.93
(t, 2), 5.00 (s, 4), 4.23 (d, 4, J ) 12.3 Hz), 3.27 (d, 4, J ) 12.9
Hz), 1.68 (bs, 2), 0.93 (bs, 4), 0.74 (bs, 4H). Anal. Calcd for
C
50H46N2O6‚1/2H2O:11 C, 77.00; H, 6.07. Found: C, 76.82; H, 5.71.
5,17-Bis(N-[4′-b r om ob en zen esu lfa n a m id o)-25,26,27,28-
tetr a k is(n en zyloxy)ca lix[4]a r en e (4) (Con e Con for m er ). To
a solution of 0.20 g (0.25 mmol) of 2a in 20 mL of HPLC-grade
CH2Cl2 was added 5 drops of pyridine followed by 0.9 g of
4-bromobenzenesulfonyl chloride, and the reaction mixture was
stirred at room temperature for 1 h (color becomes dark brown
to red). It was poured into cold water and neutralized with 50%
HCl to give a brown semisolid which was removed by spatula
and allowed to dry for 30 min. Trituration with MeOH left a
solid that was dried to give 0.26 g (85%) of 4a : mp 115-117 °C;
1H NMR (CDCl3) δ 7.54 (d, 4, J ) 8.1 Hz), 7.45 (d, 4, J ) 7.8
Hz), 7.31-7.17 (m, 20), 6.57 (bs, 6), 6.08 (s, 4), 4.97 (s, 4), 4.76
(s, 4), 4.04 (d, 4, J ) 13.2 Hz), 2.74 (d, 4, J ) 13.5 Hz); 13C NMR
(CDCl3) δ 155.53, 153.56, 138.55, 137.80, 137.40, 136.01, 135.88,
132.22, 130.44, 130.25, 129.30, 128.89, 128.48, 128.44, 128.27,
127.80, 123.66, 123.08, 77.15, 76.43, 31.49. Anal. Calcd for
C68H56N2S2Br2O8‚H2O:11 C, 64.26; H, 4.43. Found: C, 64.25; H,
4.60.
1
mp 264-267 °C; H NMR (CDCl3) δ 7.33 (bs, 8), 7.25-7.08 (m,
12), 7.04-7.01 (m, 4), 6.93-6.85 (m, 4), 6.20 (s, 4), 5.22 (s, 4),
4.62 (s, 4), 4.13 (d, 4, J ) 13.3 Hz), 2.88 (d, 4, J ) 13.5 Hz), 2.08
(t, 4, J ) 5.7 Hz), 1.61 (m, 4), 1.31 (m, 8); 13C NMR (CDCl3) δ
171.52, 156.02, 152.54, 137.96, 137.82, 137.36, 133.90, 132.12,
130.87, 129.38, 129.33, 128.76, 128.40, 128.11, 128.03, 122.86,
121.35, 78.00, 75.69, 36.01, 31.84, 27.06, 24.90, 22.91; FAB MS
m/e 981.8 [M+, calcd 981.24]. Anal. Calcd for C66H64N2O6: C,
80.79; H, 6.57. Found: C, 80.22; H, 6.62.
Br id ged com p ou n d 6b (con e con for m er ) was prepared in
similar fashion from 2a and suberoyl chloride and obtained in
67% crude yield as a white solid: mp 168-170 °C; 1H NMR
(CDCl3) δ 7.32 (s, 8), 7.30-7.09 (m, 12), 7.05 (d, 4, J ) 7.5 Hz),
6.93 (t, 2, J ) 6.7 Hz), 6.34 (s, 4), 5.24 (s, 4), 4.78 (b, 2), 4.62 (s,
4), 4.13 (d, 4, J ) 13.3 Hz), 2.86 (d, 4, J ) 13.4 Hz), 2.14 (bs, 4),
1.60 (b, 4), 1.20 (b, 4); 13C NMR (CDCl3) δ 171.52, 155.95, 151.94,
137.91, 137.71, 137.57, 133.81, 132.91, 130.90, 129.48, 129.33,
128.74, 128.42, 128.14, 128.03, 122.74, 119.23, 78.05, 75.70,
36.58, 31.88, 26.92, 24.90; FAB MS m/e 953.9 [M+, calcd 953.19].
Anal. Calcd for C64H60N2O6‚3/2H2O:11 C, 78.42; H, 6.48. Found:
C, 78.45; H, 6.68.
Br id ged com p ou n d 6c (con e con for m er ) was prepared in
similar fashion from 2a and adipoyl chloride and obtained in
64% yield: mp 125 (softening), 202-204 °C; 1H NMR (CDCl3) δ
7.38-7.30 (m, 10), 7.22-7.00 (m, 16), 6.93-6.88 (m, 2), 6.09 (s,
4), 5.16 (s, 4), 4.61 (s, 4), 4.15 (d, 4, J ) 13.5 Hz), 2.89 (d, 4, J )
13.8 Hz), 2.17 (bs, 4), 1.67 (bs, 4); 13C NMR (CDCl3) 171.62,
156.08, 152.39, 137.88, 137.81, 137.53, 134.11, 132.24, 130.78,
129.45, 129.09, 128.79, 128.35, 128.09, 127.99, 122.57, 120.13,
77.81, 75.71, 35.50, 31.77, 24.59; FAB MS m/e 925.7 [M+, calcd
925.17]. Anal. Calcd for C62H56N2O6‚2H2O:11 C, 77.48; H, 6.29.
Found: C, 77.48; H, 6.14.
Br id ged com p ou n d 7a (1,3-a lter n a te con for m er ) was
prepared in similar fashion from 2b and sebacoyl chloride and
obtained in 57% yield as a white powder which was triturated
with n-hexane followed by MeOH to give an analytical sample:
mp 295-296 °C, 1H NMR (CDCl3) δ 7.47-7.38 (m, 16), 7.24-
7.22 (m, 4), 6.87 (s, 4), 6.67 (d, 4, J ) 7.2 Hz), 6.50-6.47 (m, 4),
4.83 (s, 8), 3.46 (s, 8), 2.26 (t, 4, J ) 6.4 Hz), 1.87 (b, 4), 1.64 (s,
8); 13C NMR (CDCl3 + 2 drops of DMSO-d6) δ 170.86, 155.83,
152.21, 138.00, 137.81, 133.85, 133.10, 131.99, 131.29, 128.58,
128.17, 127.62, 127.20, 126.87, 126.67, 122.36, 121.54, 73.69,
71.72, 37.35, 36.77, 29.03, 28.81, 25.10. Anal. Calcd for
C66H64N2O6: C, 80.79; H, 6.57. Found: C, 80.45; H, 6.45.
Br id ged com p ou n d 7b (1,3-a lter n a te con for m er ) was
prepared in similar fashion from 2b and suberoyl chloride and
obtained in 55% yield as a white powder: mp 229-231 °C, 1H
NMR (CDCl3) δ 7.64 (d, 4, J ) 7.0 Hz), 7.53-7.36 (m, 16), 6.89
(s, 4), 6.78 (d, 4, J ) 6.0 Hz), 6.57 (t, 2, J ) 7.2 and 7.3 Hz), 6.40
(s, 2), 4.84 (s, 4), 4.79 (s, 4), 3.40 (dd, 8, J ) 13.44 Hz), 2.32 (bs,
4), 1.91 (bs, 4), 1.63 (bs, 4); 13C NMR (CDCl3) δ 169.96, 156.61,
152.07, 138.60, 138.09, 133.50, 132.89, 131.63, 131.31, 129.50,
5,17-Bis(N-ben zam ido)calix[4]ar en e-25,26,27,28-tetr ol (5a)
(Con e Con for m er ). A mixture of 0.42 g (0.5 mmol) of 3f in 15
mL of HPLC-grade CH2Cl2 and 0.5 mL of Me3SiBr in a l50-mL
round-bottomed flask was stirred for 2 h at room temperature.
Some white solid material separated, and the mixture was left
overnight at room temperature. Excess CH2Cl2 was removed
under reduced pressure, and the concentrated material was
poured into ice-cold water to give a precipitate which was
removed by filtration. It was triturated with n-hexane to yield
1
0.27 g (82%) of 5a as a white solid: mp 354-355 °C; H NMR
(CDCl3 + 2 drops of DMSO-d6) δ 9.87 (s, 4), 8.92 (s, 2), 7.84(d,
4, J ) 7.8 Hz), 7.47-7.35 (m, 10), 7.10 (d, 4, J ) 7.5 Hz), 6.72 (t,
2, J ) 7.8 and 7.5 Hz), 4.22 (b, 4), 3.56 (b, 4); 13C NMR (CDCl3
+ 2 drops of DMSO-d6) δ 166, 149.49, 145.10, 135.13, 133.00,
131.41, 129.03, 128.67, 128.32, 128.13, 127.64, 122.40, 121.94,
31.55. Anal. Calcd for C42H34N2O6‚1/2H2O:11 C, 75.10; H, 5.25.
Found: C, 75.15; H, 5.11.
5,17-Bis(N-acetam ido)calix[4]ar en e-25,26,27,28-tetr ol (5b)
(Con e Con for m er ). A mixture of 3c (0.35 g, 0.5 mmol) and 0.5
mL of Me3SiBr in 15 mL of HPLC-grade CH2Cl2 was stirred for
2 h at room temperature, and the reaction was worked up as
described above to give the crude product. An analytical sample
of 5b was obtained by stirring with n-hexane to yield 0.24 g
(90%) of a colorless solid: mp 297-301 °C; 1H NMR (CDCl3 + 1
drop of DMSO-d6) δ 9.80 (bs, 4), 9.16 (s, 4), 7.04 (d, 4, J ) 7.5
Hz), 6.60 (t, 2, J ) 7.2 and 7.5 Hz), 3.70-3.90 (b, 8), 2.02 (s, 6);
13C NMR (DMSO-d6) δ 167.91, 150.22, 144.75, 133.28, 128.85,
128.56, 121.12, 120.03, 31.15, 30.92, 23.97. Anal. Calcd for
C
32H30N2O6‚3/4H2O1/4CH2Cl2:11 C, 67.56; H, 5.63. Found: C,
67.46; H, 5.40.
5,17-Dia m in oca lix[4]a r en e-25,26,27,28-tetr ol (5c) (Con e
Con for m er ). A mixture of 2a (0.40 g, 0.5 mmol) and 0.8 mL of
Me3SiBr in 15 mL of CH2Cl2 was stirred for 2 h at room
temperature, and the reaction was worked up as described
above. An analytical sample of 5c was obtained by stirring the
product with n-hexane to yield 0.16 g (72%)of a colorless solid:
mp 330 °C (softening), 345 (dec) °C; 1H NMR (DMSO-d6) δ 9.80-
9.50 (b, 4), 7.12 (d, 4, J ) 7.5 Hz), 7.06 (s, 4), 6.64 (t, 2, J ) 7.2
Hz), 4.20-3.50 (b, 12); 13C NMR (DMSO-d6) δ 150.39, 149.73,

1002 J . Org. Chem., Vol. 64, No. 3, 1999
Notes
128.51, 128.12, 127.86, 127.34, 127.17, 121.41, 121.29, 75.21,
73.25, 37.24, 36.03, 28.39, 25.42. Anal. Calcd for C64H60N2O6:
C, 80.65; H, 6.34. Found: C, 80.41; H, 6.32.
dissolved in MeOH and poured over 10% HCl to give a white
precipitate which was removed by filtration and dried to yield
0.38 g (67%) of 9: mp 84-86 °C; 1H NMR (DMSO-d6) δ 7.51 (s,
2), 7.30-7.00 (m, 2), 6.60 (m, 6), 6.32 (s, 4), 4.93 (s, 4), 4.63 (s,
4), 4.08 (d, 8, J ) 7.5 Hz), 2.82 (d, 4, J ) 13.5 Hz), 2.60 (bs, 4),
2.40 (bs, 4), 1.21 (t, 6, J ) 7.0 Hz); 13C NMR (DMSO-d6) δ 173.73,
169.71, 155.67, 137.90, 135.94, 135.45, 132.12, 130.23, 129.74,
128.81, 128.50, 128.22, 128.14, 122.65, 120.85, 77.10, 76.37,
Br id ged com p ou n d 7c (1,3-a lter n a te con for m er ) was
prepared in similar fashion from 2b and adipoyl chloride and
1
obtained in 58% yield as a white powder: mp 210-211 °C; H
NMR (CDCl3) δ 7.69 (d, 4, J ) 7.5 Hz), 7.55-7.38 (m, 16), 6.91
(s, 4), 6.85 (d, 4, J ) 7.5 Hz), 6.59 (t, 2, J ) 7.5 Hz), 6.49 (s, 2),
4.81 (s, 4), 4.77 (s, 4), 3.38 (dd, 8, J ) 12.9 Hz), 2.39 (s, 4), 1.90
(s, 4); 13C NMR (CDCl3) δ 170.47, 156.05, 152.08, 138.19, 138.07,
133.50, 132.94, 131.32, 130.59, 129.39, 128.72, 128.36, 128.11,
127.57, 127.46, 121.55, 121.51, 75.84, 74.53, 37.20, 35.07, 25.84.
Anal. Calcd for C64H60N2O6: C, 80.65; H, 6.34. Found: C, 80.75;
H, 6.12.
61.22, 31.82, 31.70, 29.80, 14.54. Anal. Calcd for C68H66N2O10
C, 76.24; H, 6.21. Found: C, 75.97; H, 6.40.
:
5,17-Bis(N-4′-ca r boxyben za m id o)-26,28-bis(ben zyloxy)-
ca lix[4]-a r en e-25,27-d iol (10) (Con e Con for m er ). A stirred
solution of 0.32 g (0.05 mmol) of 2c in 50 mL of CH2Cl2 was
treated with 0.5 mL of pyridine followed by 0.5 g (0.25 mmol) of
perthaloyl dichloride. The reaction mixture was stirred at room
temperature for 6 h, and the solvent was removed under reduced
pressure to give a semisolid which was stirred with ice-cold
water to furnish a light yellow precipitate. This was stirred with
n-hexane followed by MeOH to give a white precipitate which
was removed by filtration and dried to yield 0.36 g (77%) of 10:
mp 260 °C (softening), 295-296 °C (dec); 1H NMR (DMSO-d6) δ
13.30 (s, 2), 10.10 (s, 2), 8.06-8.04 (bs, 8), 7.67 (m, 4), 7.53 (s,
4), 7.43 (m, 6), 7.03 (d, 4, J ) 6.0 Hz), 6.85 (b, 2), 5.06 (s, 4),
4.23 (d, 4, J ) 11.28 Hz), 3.42 (d, 4, J ) 11.6 Hz); 13C NMR
(DMSO-d6) δ 166.60, 164.02, 151.75, 149.22, 137.29, 136.48,
134.38, 133.35, 130.02, 129.61, 129.52, 129.39, 128.54, 128.04,
127.57, 127.43, 124.38, 121.25, 78.14, 30.81. Anal. Calcd for
C58H46N2O10‚H2O:11 C, 73.41; H, 5.10. Found: C, 73.65; H, 4.77.
5,17-Bis(N-b en zylid en e)a m in o-26,28-d ib en zyloxyca lix-
[4]a r en e-25,27-d iol (11a ) (Con e Con for m er ). To a slurry of
0.32 g (0.5 mmol) of 2c in 50 mL of absolute EtOH was added 1
mL of glacial HOAc followed by dropwise addition of 1.0 mL of
benzaldehyde. The resulting yellow solution was refluxed for 2
h and stirred at room temperature an additional 18 h. The
solvent was removed under reduced pressure, and the residue
was stirred with n-hexane to give a light yellow precipitate which
was removed by filtration and dried. The product was triturated
with MeOH to give 0.33 g (82%) of an analytical sample of 11a
as a white powder: mp 231-233 °C; 1H NMR (CDCl3) δ 8.15 (s,
2), 7.89 (s, 6), 7.66 (m, 4), 7.45 (m, 6), 7.44 (m, 6), 7.09 (s, 4),
6.87 (d, 4, J ) 7.1 Hz), 6.61 (t, 2, J ) 7.65 and 7.00 Hz), 5.08 (s,
4), 4.34 (d, 4, J ) 13.32 Hz), 3.39 (d, 4, J ) 12.87 Hz); 13C NMR
(CDCl3) δ 157.46, 152.54, 151.88, 142.95, 136.75, 136.66, 132.74,
130.90, 129.33, 128.88, 128.80, 128.56, 128.14, 127.49, 125.62,
121.45, 78.45, 31.62. Anal. Calcd for C56H46N2O4: C, 82.94; H,
5.72. Found C, 83.31; H, 5.61.
Br id ged com p ou n d 8a (con e con for m er ) was prepared in
similar fashion via high dilution from 2c and sebacoyl chloride
and obtained in 89% yield as a slightly pink powder. Alterna-
tively, it was prepared via low dilution as follows: 0.62 g (0.1
mmol) of 2c was dissolved in 150 mL of HPLC-grade CH2Cl2,
treated with 0.5 mL of pyridine, and stirred for 2 min. A solution
of 0.31 g (1.5 equiv) of sebacoyl chloride in 10 mL of CH2Cl2 was
added dropwise with stirring at room temperature (pale pink
color precipitate formed at the time of addition). After all of the
sebacoyl chloride had been added, a brown semisolid settled to
the bottom of the flask and was partially removed by spatula.
The remaining solution was concentrated under reduced pres-
sure and stirred with n-hexane, and the pale pink precipitate
was removed by filtration and mixed with the previously
separated semisolid. This was stirred with MeOH for 2 h to give
a pink powder which was further stirred with EtOAc followed
by Me2CO and finally with MeOH to give 0.71 g (85%) of an
analytical sample: mp 222-224 °C; 1H NMR (DMSO-d6) δ 9.51
(s, 2), 7.88 (s, 2), 7.63 (s, 2), 7.39 (s, 6), 7.31 (s, 4), 6.94 (s, 4),
6.81 (s, 2), 5.00 (s, 4), 4.15 (d, 4, J ) 15.6 Hz), 3.32 (d, 4, J )
15.6 Hz), 2.21 (s, 4), 1.55 (bs, 4), 1.27 (s, 8); 13C NMR (DMSO-
d6) δ 170.47, 151.72, 148.40, 136.47, 133.39, 130.97, 128.81,
128.53, 128.02, 127.52, 127.29, 125.40, 120.07, 78.08, 36.19,
30.80, 28.72, 25.16. Anal. Calcd for C52H52N2O6‚1/2H2O:11 C,
77.10; H, 6.60. Found: C, 77.05; H, 6.39.
Br id ged com p ou n d 8b (con e con for m er ) was preapred by
the low dilution procedure described above from 2c and suberoyl
1
chloride and obtained in 82% yield: mp 227-228 °C; H NMR
(DMSO-d6) δ 9.52 (s, 2), 7.89 (s, 2), 7.63 (s, 4), 7.39 (s, 6), 7.31
(s, 4), 6.95 (d, 4, J ) 6.8 Hz), 6.81 (m, 2), 5.01 (s, 4), 4.16 (d, 4,
J ) 12.2 Hz), 3.30 (b, 4), 2.21 (s, 4), 1.55 (bs, 4), 1.29 (s, 4); 13C
NMR (DMSO-d6) δ 170.49, 151.73, 148.42, 136.47, 133.39,
130.97, 128.75, 128.45, 128.02, 127.48, 127.30, 125.39, 120.13,
78.11, 36.18, 30.80, 28.56, 25.12. Anal. Calcd for C50H48N2O6‚
H2O:11 C, 75.93; H, 6.37. Found: C, 75.96; H, 5.96.
5,17-B i s (N -[4′-m e t h o x y b e n z y li d e n e ])a m i n o -26,28-
diben zyloxycalix[4]ar en e-25,27-diol (11b) (con e con for m er )
was prepared as described above from 2c and p-methoxyben-
zaldehyde and obtained as a white powder in 78% yield: mp
Br id ged com p ou n d 8c (con e con for m er ) was prepared by
the low dilution procedure described above from 2c and pimeloyl
1
262-264 °C; H NMR (CDCl3) δ 8.42 (s, 2), 7.84 (s, 2), 7.81 (s,
1
chloride and obtained in 82% yield: mp 230-232 °C; H NMR
4), 7.67-7.64 (m, 4), 7.39-7.38 (m, 6), 7.04 (s, 4), 6.97 (d, 4, J )
8.6 Hz), 6.90 (d, 4, J ) 7.5 Hz), 6.67 (t, 2, J ) 7.53 and 7.1 Hz),
5.07 (s, 4), 4.34 (d, 4, J ) 13.3 Hz), 3.85 (s, 6), 3.38 (d, 4, J )
13.32 Hz); 13C NMR (CDCl3) δ 161.84, 156.94, 152.08, 151.89,
143.36, 136.74, 132.87, 130.16, 129.68, 129.28, 128.83, 128.46,
128.09, 127.47, 125.55, 121.25, 114.17, 78.42, 55.30, 31.60. Anal.
Calcd for C58H50N2O6: C, 79.98; H, 5.79. Found: C, 79.74; H,
5.69.
(DMSO-d6) δ 9.51 (s, 2), 7.87 (s, 2), 7.63 (s, 4), 7.39 (s, 6), 7.31
(s, 4), 6.94 (s, 4), 6.80 (b, 2), 5.00 (s, 4), 4.16 (d, 4, J ) 10.74 Hz),
3.34 (b, 4), 2.22 (s, 4), 1.58 (s, 4), 1.31 (s, 2); 13C NMR (DMSO-
d6) δ 170.42, 151.72, 148.41, 136.46, 133.38, 130.92, 128.81,
128.52, 128.01, 127.52, 127.30, 125.35, 120.14, 78.09, 36.03,
30.75, 28.41, 24.97. Anal. Calcd for C49H46N2O6‚H2O:11 C, 75.75;
H, 6.23. Found: C, 75.71; H, 5.99.
Br id ged com p ou n d 8d (con e con for m er ) was prepared
by the low dilution procedure described above from 2c and
adipoyl chloride and obtained in 79% yield: mp 236-238 °C;
1H NMR (DMSO-d6) δ 9.53 (s, 2), 7.88 (s, 2), 7.64 (s, 4), 7.40 (s,
6), 7.31 (s, 4), 6.95 (d, 4, J ) 6.4 Hz), 6.80 (m, 2), 5.01 (s, 4), 4.16
(d, 4, J ) 15.9 Hz), 3.30 (bd, 4), 2.24 (s, 4), 1.58 (bs, 4); 13C NMR
(DMSO-d6) δ 170.31, 151.72, 148.44, 136.47, 133.38, 130.89,
128.82, 128.52, 128.02, 127.54, 127.30, 125.37, 120.15, 78.10,
36.06, 30.77, 24.98. Anal. Calcd for C48H44N2O6‚H2O:11 C, 75.57;
H, 6.08. Found: C, 75.48; H, 5.87.
5,17-Bis(N-3′-ca r b oet h oxyp r op ion a m id o)-25,26,27,28-
tetr a k is(ben zyloxy)ca lix[4]a r en e (9) (Con e Con for m er ). A
stirred solution of 0.40 g (0.05 mmol) of 2a in 50 mL of CH2Cl2
was treated with 0.5 mL of pyridine followed by 1.5 mL of ethyl
succinoyl monochloride. The reaction mixture was stirred at
room temperature for 6 h, and the solvent was removed under
reduced pressure to give a semisolid which was passed through
a silica gel column (eluted with CH2Cl2). The product was
5,17-B i s (N -[2′-m e t h o x y b e n z y li d e n e ])a m i n o -26,28-
diben zyloxycalix[4]ar en e-25,27-diol (11c) (con e con for m er )
was prepared as described above from 2c and o-methoxyben-
zaldehyde and obtained as a white powder in 76% yield: mp
1
287-288 °C; H NMR (CDCl3) δ 8.94 (s, 2), 8.13 (d, 2, J ) 7.8
Hz), 7.77 (s, 2), 7.66 (m, 4), 7.43-7.38 (m, 8), 7.07 (s, 4), 7.03
(m, 2), 7.94 (m, 6), 6.72 (t, 2, J ) 7.5 Hz), 5.08 (s, 4), 4.34 (d, 4,
J ) 13.02 Hz), 3.91 (s, 6), 3.39 (d, 4, J ) 13.8 Hz); 13C NMR
(CDCl3) δ 158.89, 152.69, 151.67, 143.43, 136.13, 132.99, 131.95,
129.02, 128.52, 127.92, 127.26, 126.76, 125.84, 124.59, 121.17,
120.41, 110.90, 78.33, 55.33, 31.16. Anal. Calcd for C58H50N2O6‚
H2O:11 C, 79.16; H, 5.84. Found: C, 78.98; H, 5.67.
5 ,1 7 -B i s (N -[r-m e t h y l b e n z y l i d e n e ])a m i n o -2 6 ,2 8 -
diben zyloxycalix[4]ar en e-25,27-diol (11d) (con e con for m er )
was prepared as described above from 2c and acetophenone and
obtained in 62% yield: mp 263-265 °C; 1H NMR (CDCl3) δ 7.96
(m, 4), 7.66 (m, 4), 7.59 (s, 2), 7.44 (b, 6), 7.38 (b, 6), 6.85 (d, 4,
J ) 7.1 Hz), 6.66-6.59 (m, 6), 5.05 (s, 4), 4.35 (d, 4, J ) 12.9

Notes
J . Org. Chem., Vol. 64, No. 3, 1999 1003
Hz), 3.32 (d, 4, J ) 13.0 Hz), 2.24 (s, 6); 13C NMR (CDCl3) δ
165.29, 151.88, 149.70, 143.02, 139.95, 136.88, 132.87, 130.16,
129.18, 128.79, 128.30, 127.97, 127.49, 127.42, 127.11, 125.44,
120.02, 78.31, 31.55, 17.36. Anal. Calcd for C58H50N2O4‚H2O:11
C, 81.28; H, 6.12. Found: C, 81.03; H, 5.81.
for m er ) was prepared as described above from 2b and p-meth-
oxybenzaldehyde and obtained in 71% yield: mp 239-241 °C;
1H NMR (CDCl3) δ 7.60 (s, 2), 7.53 (d, 4, J ) 7.6 Hz), 7.45-7.38
(m, 6), 7.20-7.12 (m, 12), 7.00-6.95 (m, 2), 6.88 (d, 4, J ) 7.8
Hz), 6.74-6.69 (m, 8), 6.49 (t, 2, J ) 7.2 Hz), 4.87 (s, 4), 4.86 (s,
4), 3.88 (s, 6), 3.64 (dd, 8, J ) 14.9 Hz); 13C NMR (CDCl3) δ
161.50, 156.72, 156.11, 154.38, 145.22, 138.12, 137.83, 134.54,
133.69, 131.21, 130.30, 129.95, 128.42, 127.92, 127.10, 126.90,
126.78, 126.68, 123.41, 122.27, 113.76, 72.37, 72.26, 55.38, 37.38.
Anal. Calcd for C72H62N2O6: C, 82.26; H, 5.94. Found: C, 82.21;
H, 6.14.
5,17-B is (N -b e n zy lid e n e )a m in o -25,26,27,28-t e t r a k is -
(ben zyloxy)ca lix[4]a r en e (12a ) (1,3-a lter n a te con for m er )
was prepared as described above from 2b and benzaldehyde and
1
obtained as a white powder in 76% yield: mp 147-149 °C; H
NMR (CDCl3) δ 7.66 (s, 2), 7.60-7.57 (m, 4), 7.45-7.33 (m, 12),
7.20-7.11 (m, 12), 6.97-6.95 (m, 2), 6.75-6.72 (m, 8), 6.49 (t, 2,
J ) 7.2 Hz), 4.87 (s, 8), 3.66 (dd, 8, J ) 13.5 Hz); 13C NMR
(CDCl3) δ 157.29, 156.08, 154.73, 144.92, 138.04, 137.76, 136.82,
134.63, 133.66, 131.21, 130.41, 128.67, 128.42, 128.35, 127.92,
127.13, 127.07, 126.68, 123.54, 122.33, 72.26, 37.40. Anal. Calcd
for C70H58N2O4‚H2O:11 C, 84.06; H, 5.95. Found: C, 84.00; H,
5.83.
Ack n ow led gm en t. We are indebted to the National
Science Foundation and the Robert A. Welch Founda-
tion for generous support of this work.
5,17-Bis(N-[4′-m eth oxyben zylid en e])a m in o-25,26,27,28-
tetr a k is(ben zyloxy)ca lix[4]a r en e (12b) (1,3-a lter n a te con -
J O980903Z