Cage-like amines in the synthesis and oxidation of camphor-10-sulfonic acid amides

Article abstract of DOI:10.1134/S1070428009070057

Reactions of bicyclo[2.2.1]hept-5-en-exo- and -endo-2-ylmethanamines, exo-5,6-epoxybicyclo-[2.2.1]hept-exo-2-ylmethanamine, 1-(bicyclo[2.2.1]hept-2- yl)ethanamine, and 1-(1-adamantyl)ethanamine with camphor-10-sulfonyl chloride in chloroform in the presence of triethylamine gave the corresponding sulfonamides having two cage-like fragments. Stereoisomeric N-(bicyclo[2.2.1] hept-5-en-2-ylmethyl)camphor-10-sulfonamides were oxidized with peroxyphthalic acid generated in situ from phthalic anhydride and 50% hydrogen peroxide. The exo stereoisomer was thus converted into the corresponding 5,6-epoxy derivative, while the endo isomer gave rise to 4-(7,7-dimethyl-2-oxobicyclo[2.2.1]hept-1- ylmethyl)-4-azatricyclo[4.2.1.0^3,7]-nonan-exo-2-ol (substituted azabrendane). The structure of the synthesized camphor-10-sulfonamides was confirmed by IR and ¹H and ¹³C NMR spectra with the use of homo- (COSY) and heteronuclear ¹H-¹³C correlation techniques (HMQC, HMBC). Heterocyclization of sulfonamides of the norbornene series was also simulated by quantum-chemical calculations at the PM3 and BHandHLYP/6-31G(d) levels of theory.

Full text of DOI:10.1134/S1070428009070057

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2009, Vol. 45, No. 7, pp. 1007–1017. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © L.I. Kas’yan, V.A. Pal’chikov, A.V. Turov, S.A. Prid’ma, A.V. Tokar’, 2009, published in Zhurnal Organicheskoi Khimii, 2009,
Vol. 45, No. 7, pp. 1021–1030.
Cage-Like Amines in the Synthesis and Oxidation
of Camphor-10-sulfonic Acid Amides
L. I. Kas’yana, V. A. Pal’chikova, A. V. Turovb, S. A. Prid’maa, and A. V. Tokar’a
a Oles’Gonchar Dnepropetrovsk National University, pr. Gagarina 72, Dnepropetrovsk, 49010 Ukraine
e-mail: palchikoff@mail.ru
b Taras Shevchenko Kiev National University, Kiev, Ukraine
Received July 1, 2008
Abstract—Reactions of bicyclo[2.2.1]hept-5-en-exo- and -endo-2-ylmethanamines, exo-5,6-epoxybicyclo-
[2.2.1]hept-exo-2-ylmethanamine, 1-(bicyclo[2.2.1]hept-2-yl)ethanamine, and 1-(1-adamantyl)ethanamine with
camphor-10-sulfonyl chloride in chloroform in the presence of triethylamine gave the corresponding sulfon-
amides having two cage-like fragments. Stereoisomeric N-(bicyclo[2.2.1]hept-5-en-2-ylmethyl)camphor-10-
sulfonamides were oxidized with peroxyphthalic acid generated in situ from phthalic anhydride and 50% hy-
drogen peroxide. The exo stereoisomer was thus converted into the corresponding 5,6-epoxy derivative, while
the endo isomer gave rise to 4-(7,7-dimethyl-2-oxobicyclo[2.2.1]hept-1-ylmethyl)-4-azatricyclo[4.2.1.03,7]-
nonan-exo-2-ol (substituted azabrendane). The structure of the synthesized camphor-10-sulfonamides was
1
1
confirmed by IR and H and 13C NMR spectra with the use of homo- (COSY) and heteronuclear H–13C
correlation techniques (HMQC, HMBC). Heterocyclization of sulfonamides of the norbornene series was also
simulated by quantum-chemical calculations at the PM3 and BHandHLYP/6-31G(d) levels of theory.
DOI: 10.1134/S1070428009070057
The chemistry of sulfonamides vigorously devel-
oped during the last century [1]; however, some its
aspects have been extensively studied only in the
recent years. Some new studies have been concerned
with sulfonamides having norbornene, norbornane, or
other cage-like structure and possessing two or more
pharmacophoric fragments. Although the spectrum of
biological activity of sulfonamides is very broad, there
is no doubt that the activity of this group of com-
pounds is largely determined by the contribution of
rigid bicyclic skeleton which is structurally related to
natural terpenoids. Amines of the norbornene and nor-
bornane series were used to obtain sulfonamides acting
as thromboxane receptor antagonists and exhibiting
vasodilator and other kinds of biological activity [2].
For example, effective thromboxane receptor anta-
gonists are compound Ia (S-145) and its three stereo-
isomers [3].
Hamanaka et al. [4] examined how the distance of
sulfonamide group from the cage-like fragment and
substituents in the aromatic fragment affect the biolog-
ical activity of compounds like Ia. It was presumed
that conformational rigidity of the bicyclic skeleton is
the main factor responsible for biological activity. Nu-
merous examples of biologically active sulfonamides
with a simpler structure are known. Transformation of
compound Ib at the hydroxymethyl group gave sul-
fonamides possessing antithrombotic, antisclerotic, and
antiischemic activity [5]. Compound Ic [6] and its
analogs are effective diuretics.
COOH
NHSO2C6H4Cl-4
CH2OH
NHSO2Ph
Ia
Ib
H
N
Cl
The results of a number of studies have shown that
introduction of a pharmacophoric cage-like fragment
into molecules of aromatic sulfonamides endows them
with new valuable neurotropic properties [7]. In partic-
NH
H2NSO2
S
O
O
Ic
1007

KAS’YAN et al.
1008
ular, exo- and endo-stereoisomeric sulfonamides Id
and Ie exhibit analgesic, anticonvulsant, antihypoxic,
tranquilizing, and (in some cases) antiphlogistic
activity.
isolation of optically active compounds from their
racemic mixtures [8] in the preparation of pharma-
ceutical agents [9] that are often salts derived from
biologically active bases. Some of these compounds
were found to exhibit antitumor effect [10] and control
breath. Syntheses of chiral precursors, chiral catalysts,
and chiral reagents on the basis of camphor are
extensively studied [11, 12]. Syntheses of camphor-10-
sulfonyl halides [13], reactions of the latter with am-
monia, and transformations of optically active (+)- and
(–)-sulfonamides into camphorsulfonyloxaziridines
[14] were reported. Sulfonamides IIa–IIe are effective
as ligands in enantioselective catalytic addition of
diethylzinc to aldehydes and ketones [15]. Apart from
traditional sulfonamides, Oppoltzer’s sultam (IIIa) and
its N-substituted derivatives IIIb and IIIc were syn-
thesized [16].
O
O
S
N
X
H
Id
O
O
S
N
X
H
Ie
The goal of the present work to synthesize new
potential biologically active compounds via introduc-
tion into molecules of neurotropic cage-like sulfon-
amides of the second cage-like fragment using cam-
phor-10-sulfonyl chloride. The latter is an accessible
derivative of natural or synthetic camphor. Both
natural and synthetic camphor is widely used for the
In the present work we examined reactions of cam-
phor-10-sulfonyl chloride [17] with cage-like bicyclic
amines IVa–IVc which were synthesized according to
Scheme 1. The key stage in the synthesis of stereo-
chemically pure exo- and endo-isomeric amines IVa
and IVb was separation of the corresponding nitriles
Va and Vb by fractional distillation. Compounds Va
Me
Me
Me
Me
O
O
S
OH
OH
N
H
Me
Me
HN
S
SO2NHCH2Ar
O2S NH
O
O
OH
Me
Me
OH
Me
IIa
IIb
IIc
Me
Me
Me
O
O
S
N
OH
H
Me
Me
HN
S
S
NH
N
O
O
OH
Me
O
N
O
Bu
R
OH
Me
IId
IIe
Me
Me
Me
Me
Me
Me
O
O
H
OH
H
N
HN
O
N
N
OMe
S
S
S
O
O
O
O
O
MeO
IIIb
OMe
IIIa
IIIb
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 7 2009

CAGE-LIKE AMINES IN THE SYNTHESIS AND OXIDATION OF CAMPHOR-10-SULFONIC
1009
Scheme 1.
CO2H
CO3H
LiAlH4, Et2O
O
O
CN
NH2
Vc
IVc
CN
LiAlH4, Et2O
Va
NH2
+
CN
H2C
IVa
LiAlH4, Et2O
CN
CH2NH2
IVb
Vb
and Vb were obtained in turn by the Diels–Alder reac-
tion of cyclopentadiene with acrylonitrile [18]. Nitriles
Va and Vb were then converted into amines IVa and
IVb by reduction with lithium tetrahydridoaluminate
in boiling diethyl ether. Oxidation of exo-nitrile Va
with peroxyphthalic acid generated in situ from
phthalic anhydride and 30% aqueous hydrogen perox-
ide gave tricyclic compound Vc which was then
reduced to amine IVc [19]. The reduction of Vc was
chemoselective: only the cyano group was involved,
while the oxirane ring remained unchanged. Here, the
selectivity is determined by steric factors which ham-
per rear attack by LiAlH4 on the electrophilic centers
of the oxirane fragment [20]. In addition, amines with
saturated hydrocarbon skeletons were included, name-
ly 1-(bicyclo[2.2.1]hept-2-yl)ethanamine (IVd) [21]
and 1-(1-adamantyl)ethanamine (IVe) [22]; the corre-
sponding hydrochlorides are known as antiviral drugs
Deitiforin and Rimantadine [6].
1154 (SO2), and 3315–3300 cm–1 (NH) and carbonyl
group in the camphor fragment at 1752–1741 cm–1
[23]. Vibrations of the strained double C=C bond in
molecule VII gave rise to absorption bands at 3072
[ν(=C–H)] and 730 cm–1 [δ(=C–H)] [24], and absorp-
tion at 855 cm–1 in the spectrum of VIII was assigned
to the epoxynorbornane fragment [19, 20].
Compounds VI–VIII and X displayed complex
1
patterns in the H NMR spectra which were analyzed
using the known spectrum of camphor-10-sulfonic
acid. The latter contains doublet signals at δ 3.01 and
2.55 ppm (2J = 15.0 Hz) due to protons in the exo-
cyclic methylene group neighboring to the C1′ chiral
center. Signals from the methyl groups appeared at
δ 1.04 and 0.76 ppm; the difference in the chemical
shifts results from anisotropic properties of the carbon-
yl group which is closer to one of the methyl groups.
Analogous signals are observed in the spectra of VI–
VIII and X, but the spectral patterns were complicated
by the presence of multiplet signals from seven non-
equivalent protons on C3′, C4′, C5′, and C6′ in the
camphor fragment, so that assignment of signals to
particular protons was fairly difficult. For this purpose,
NH2
1
we used homonuclear (COSY) and H–13C heteronu-
NH2
Me
Me
IVd
clear correlation techniques (HMQC, HMBC) [25, 26];
the complete list of correlations found for compound
VII is given in Table 1.
Taking into account that signals from some protons
in both bicyclic fragments of sulfonamide VII may be
assigned unambiguously without resorting to special
NMR techniques, the observed correlations allowed us
to reliably assign all other signals in the spectrum of
VII and, by analogy, in the spectra of VI, VIII, and X.
The problem was facilitated by the fact that most
IVe
By reacting amines IVa–IVe with camphor-10-sul-
fonyl chloride in chloroform in the presence of tri-
ethylamine we obtained compounds VI–X (Scheme 2).
The structure of crystalline sulfonamides VI–X having
two cage-like fragments was confirmed by IR and
NMR (1H and 13C) spectra. Their IR spectra contained
absorption bands due to stretching vibrations of the
sulfonamide group in the regions 1400–1335, 1180–
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 7 2009

KAS’YAN et al.
1010
Scheme 2.
5'
Me8'
Me
6
6'
5
Me
CHCl3, Et3N
20–25°C
7'
4'
3'
1
Me
7
4
9'
Me
S
1'
SO2Cl
O
H
H
+
Me
S
N
N
2
2'
10'
3
NH2
O
O
O
O
O
O
IVa
VI
VII
O
Me
Me
Me
H
H
H
Me
S
Me
S
Me
S
N
N
N
O
O
O
O
O
O
O
O
O
Me
Me
VIII
IX
X
carbon atoms in the molecules of these compounds are
linked to hydrogens, so that correlations through one
bond could be used for signal assignment [25].
assignment of exo or endo configuration to sulfon-
amides of the norbornane series. The H NMR spec-
trum of endo-stereoisomer VII showed a considerable
nonequivalence of the 5-H and 6-H protons in the nor-
bornene fragment (δ 5.97 and 6.16 ppm), large dif-
ference in the chemical shifts of exo-3-H and endo-3-H
1
The 1H NMR parameters of compounds VI and VII
and 13C NMR parameters of VII confirmed the validity
of criteria proposed by us previously [27–29] for the
Table 1. Correlations in the two-dimensional NMR spectra of compound VII
δH, ppm
HMQC, δC, ppm
HMBC, δC, ppm
COSY, δH, ppm
2.61, 2.72
7.03
6.16
5.97
3.26
2.86
2.84
2.76
2.72
2.61
2.36
2.33
2.18
2.04
1.94
1.91
1.79
1.51
1.39
1.33
1.22
1.01
0.79
0.49
–
137.80
133.00
48.2
44.3
48.2
–
–
49.6, 44.3, 42.7
5.97, 2.76
49.6, 44.3, 42.7
6.16, 2.86
215.4, 58.6, 48.2, 25.2
137.8
2.86
3.26, 5.97
215.4, 58.6, 48.2, 25.2
–
1.33, 1.22
1.79, 1.33, 1.22, 6.16
2.61, 2.18, 7.03
2.72, 2.18, 7.03
1.51
47.4
47.4
25.2
42.7
39.6
42.7
27.0
42.7
30.5
25.2
27.0
49.6
49.6
20.2
20.0
30.5
39.6, 44.3, 30.5
39.6, 44.3, 30.5
58.6
215.4, 58.6, 42.7, 27.0
42.7
1.91, 2.04, 1.39
2.72, 2.61, 1.79, 0.49
2.33, 1.91
215.4, 58.5, 25.2, 20.0
–
1.51, 1.39
215.4, 58.5, 48.2, 42.8, 27.0, 20.0
137.8, 47.4, 42.8
215.4, 58.5, 48.2, 27.0
42.8, 48.2, 58.5, 25.2
39.6, 30.5
2.33, 2.04
2.76, 2.18, 0.49
2.36, 1.94, 1.39
2.36, 1.94, 1.51
1.22, 2.76, 2.86
2.86, 2.76, 1.33
–
137.8, 133.0, 44.3, 42.8, 39.6, 30.5, 27.0
48.2, 42.8, 20.0, 58.5
48.3, 42.8, 20.2, 58.5
137.8, 49.6, 47.4, 42.6, 39.6
–
1.79, 2.18
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 7 2009

CAGE-LIKE AMINES IN THE SYNTHESIS AND OXIDATION OF CAMPHOR-10-SULFONIC
1011
Increased interest in compounds having camphor
fragments arises from the possibility for their oxidation
according to Baeyer–Villiger. It is known that oxida-
tion of camphor (XIIa) with Caro’s acid (H2SO5, per-
oxomonosulfuric acid) or 40% peroxyacetic acid gives
campholide (XIIb) [31]. The formation of isomeric
lactone XIIc in the oxidation of XIIa with peroxy-
acetic acid in the presence of sodium acetate was also
reported.
(δ 1.79 and 0.49 ppm), and unusually upfield position
of the endo-3-H signal due to anisotropy of magnetic
susceptibility of the exocyclic C2–C8 bond. exo-Sul-
fonamide VI is characterized by different parameters
and quite different degree of nonequivalence of the
5-H/6-H and exo-3-H/endo-3-H protons (δ 6.11, 6.07;
1.14–1.19 ppm). Protons in the adamantane fragment
1
of compound X resonated in the H NMR spectrum in
the regions δ 1.60–1.73 and 2.00–2.10 ppm.
Me
Me
In the recent years, a number of studies were per-
formed on stereochemical aspects of epoxidation of
sulfonamides Id and Ie and their analogs having alkyl
and cycloalkyl groups on the sulfonamide group.
Treatment with peroxyphthalic acid of substituted nor-
bornenes with exo-orientation of substituent in the
cage-like fragment resulted in the formation of the
corresponding epoxy derivatives, whereas the oxida-
tion of endo stereoisomers was not selective, and both
epoxy derivatives like XIa and heterocyclization prod-
ucts, substituted 4-azatricyclo[4.2.1.03,7]nonanes (aza-
brendanes) like XІb were obtained [20, 27, 30]
(Scheme 3).
Me
O
O
O
Me
Me
Me
Me
Me
Me
O
O
XIIa
XIIb
XIIc
We examined oxidation of unsaturated sulfon-
amides VI and VII with monoperoxyphthalic acid
generated in situ from phthalic anhydride and 50%
aqueous hydrogen peroxide in ethyl acetate. The
oxidation of exo-sulfonamide VI was chemoselective:
it occurred at the strained double C=C bond, the cam-
phor fragment remaining intact, and afforded epoxy-
norbornane VIII which was also synthesized by in-
dependent method. The IR spectrum of VIII contained
a carbonyl absorption band at 1752 cm–1, and its
1H NMR spectrum indicated the presence of an epoxy-
norbornane fragment: one-proton doublets were ob-
served at δ 3.12 and 3.08 ppm (3J5, 6 = 3.8 Hz). In
addition, the anti-7-H signal was displaced upfield
(δ 0.79 ppm), for that proton appears directly above
the plane of the exo-oriented oxirane ring [32]. The
oxidation of endo-sulfonamide VII gave compound
XIII containing no epoxide ring [33] (Scheme 4).
Scheme 3.
O
R'CO3H
NHSO2R
NHSO2R
XIa
HO
Scheme 4.
N
8
RSO2
XIb
CO2H
HO
2
Me
1
3
9
CO3H
7
N4
Heterocyclization accompanied epoxidation of all
mono- and some disubstituted benzenesulfonamides of
the endo series, as well as of N-alkyl- and N-benzyl-
sulfonamides, but it did not occur in the oxidation of
endo-isomeric arenesulfonamides having electron-
withdrawing substituents (primarily in the ortho posi-
tion of the benzene ring) and N-perfluoroalkyl sulfon-
amides [28]. No heterocyclization was observed in the
epoxidation of N-(bicyclo[2.2.1]hept-5-en-endo-2-yl-
methyl)cyclohexanesulfonamide [27], which suggests
that the formation of azabrendane systems is hindered
for steric reasons (the presence of a bulky substituent
at the sulfonyl group).
VII
Me
S
6
5
O
O
O
XIII
HO
HN
XIV
1
Assignment of signals in the H NMR spectrum of
the oxidation product required increased attention, for
the spectrum changed toward simpler pattern in several
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 7 2009

KAS’YAN et al.
1012
80
75
70
65
60
55
50
45
40
35
30
25
20
δC, ppm
Fig. 1. 13C NMR spectrum (DEPT) of compound XIII (CDCl3, 100.7 MHz).
hours after dissolution. These findings, as well as dou-
bling of some signals in the NMR spectra, are likely to
indicate the presence of conformers or diastereoiso-
mers. From the spectrum recorded using DEPT pulse
sequence (Fig. 1) we determined the number of CH2
and CH groups, which corresponded to structure XIII.
1
Both 13C and H signals were assigned using homonu-
1.44
1.92
clear (COSY) and heteronuclear correlation experi-
ments [through one (HMQC) and 2–3 chemical bonds
(HMBC)]. The results are collected in Table 2 [25] and
illustrated by Fig. 2.
2.19
34.1
1.00
2.85 HO
41.6
81.5
1.92
33.0
45.2
2.68
The structure of XIII as substituted azabrendane is
confirmed by the presence of one-proton signals at
δ 3.71 and 3.61 ppm (a singlet and a doublet with
3J3,7 = 5.1 Hz), which belong to 2-H and 3-H in the
norbornane fragment, as well as of multiplet signals at
δ 3.28 and 3.40 ppm (5-H). The 13C NMR spectrum of
XIII contained signals from C2 and C3 at δC 81.5 and
69.5 ppm, respectively, and other signals whose posi-
tions were similar to those in the spectrum of azabren-
dane (XIV) (δC 83.3, 69.7 ppm [34]). The presence of
a signal at δC 216.0 ppm indicated that the carbonyl
group remained unchanged. Presumably, participation
of the carbonyl group in the Baeyer–Villiger oxidation
is determined by the nature of oxidant (peroxyphthalic
acid) or steric effect of the neighboring cage-like frag-
3.61
2.36
69.5
37.2
3.71
N
54.6
O2S
3.40
1.13
20.2
2.36
1.96
3.28
CH
3
0.89
20.0
CH
3
48.2
42.9
58.5
O
2.51
216.0
25.4
43.0
3.48
2.05
46.1
27.2
1.64
2.11
2.84
1.44
Fig. 2. Principal correlations in the NMR spectra of com-
pound XIII.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 7 2009

CAGE-LIKE AMINES IN THE SYNTHESIS AND OXIDATION OF CAMPHOR-10-SULFONIC
1013
Table 2. Heteronuclear correlations in the two-dimensional
NMR spectra of compound XIII
ment. It should be emphasized that the rigid bulky sub-
stituent in the epoxynorbornane intermediate creates
no steric hindrances to heterocyclization.
δH,
HMQC, δC,
HMBC, δC, ppm
The formation of compound XIII was studied by
quantum-chemical simulation of heterocyclization of
probable epoxy intermediate XVa in comparison to its
analogs XVb–XVd having different substituents at the
sulfonamide group [27]. Transition states were local-
ized using theoretical models which ensured detailed
determination of the heterocyclization conditions. Het-
erocyclization in the gas phase was described by model
A; the effect of electrophilic activation of the oxygen
atom in the epoxide ring by formic acid molecule was
taken into account using structure B; and experimental
conditions were reflected most completely by model C
due to consideration of specific solvation with ethyl
acetate (supermolecular approximation) [27, 35]. The
calculations of models A–C were performed in terms
of PM3 semiempirical quantum-chemical approxima-
tion [36], while solvent effect in model C was de-
scribed with the aid of the Onsager solvation model
[ε = 6.02, BHandHLYP hybrid potential, standard
6-31G(d) basis set] [37, 38]. The activation barriers
were calculated relative to epoxides assumed to be the
corresponding prereaction complexes. The results of
calculations are collected in Table 3.
ppm
ppm
3.71
3.61
3.48
3.40
3.28
2.84
2.68
2.51
2.36
2.19
2.11
2.05
1.96
81.5
69.5
46.1
54.6
54.0
46.1
45.2
25.4
45.2, 34.1
81.5, 54.6
58.5, 48.3, 25.4, 33.0, 215.9
69.5, 45.2, 37.2, 33.0
58.5, 48.3, 25.4, 215.9
81.5, 41.6, 33.0
58.5, 27.2, 215.9
42.9, 37.3 41.6, 27.2
41.6
43.0
27.2
42.9
81.5, 69.6, 45.2, 37.2
58.5, 25.4, 215.9, 42.9
–
81.5, 54.4, 48.3, 42.9, 41.6, 37.3,
33.0, 27.2, 215.9
1.92
1.64
33.0, 34.1
25.4
58.5, 48.3, 27.2, 215.9
81.5, 69.6, 48.3, 46.1, 42.9, 41.6,
37.2, 33.0, 25.4
1.44
27.2, 34.1
1.13
1.00
0.89
33.0
20.0
–
58.5, 48.2, 43.0, 20.0
81.5, 54.4, 42.9, 34.1
58.5, 48.2, 43.0, 20.2
The calculated geometric parameters of the transi-
tion states correspond to the classical mechanism of
epoxide ring opening [39]. As might be expected, the
ΔEa values calculated for model C were most consist-
ent with the experimental data. In fact, the data in
Table 3 show that structures XVa–XVc are equally
prone to form tricyclic azabrendane systems, but the
activation barrier for cyclohexanesulfonamide XVd
hampers heterocyclization. The calculation results are
very consistent with the experimental data [27, 30],
demonstrating that the possibility for intramolecular
cyclization is determined by not only size but also
other parameters of substituents in the epoxide mole-
cules, in particular by their conformational mobility
which increases due to the presence of a methylene
bridging group in structure XVa.
EXPERIMENTAL
The IR spectra were measured in the range from
4000 to 400 cm–1 on a UR-20 spectrometer from
samples prepared as KBr pellets. The 1H NMR spectra
1.728 Å
1.726 Å
O
O
O
H
O
O
H
O
H
H
O
1.818–1828 Å
HN
HN
H
N
O
O
S
O
S
O
S
EtO
O
O
O
R
R
R
Me
C (solution)
A (gas phase)
B (gas phase)
XIVa–XIVd
Me
Me
R =
(a), Ph (b), PhCH2 (c), cyclo-C6H11 (d).
O
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 7 2009

KAS’YAN et al.
1014
Table 3. Principal geometric parameters of transition states in the formation of azabrendane systems and the corresponding
activation barriers
Bond length, Å
O–C3 C3–N
Angle, deg
OC2C3
Activation barrier,
kJ/mol
Compound no.
OC3N
OC2C3N
Model A (PM3)
ΔHa
XVa
XVb
XVc
XVd
2.097
2.087
2.095
2.099
1.979
1.985
1.981
1.977
144.73
144.89
144.79
144.75
93.25
92.75
93.15
93.36
146.43
146.93
146.40
146.63
242.80
235.59
244.17
241.01
Model B (PM3)
ΔHa
XVa
XVb
XVc
XVd
2.069
2.059
2.069
2.075
2.026
2.031
2.028
2.030
145.71
145.95
145.79
145.71
91.65
91.10
91.63
91.96
148.73
148.91
148.59
148.29
216.56
209.65
218.07
222.45
Model C [BHandHLYP/6-31G(d)//PM3]
ΔEa
XVa
XVb
XVc
XVd
2.045
2.038
2.043
2.047
2.033
2.036
2.032
2.031
145.72
146.08
145.97
145.60
90.40
89.97
90.24
90.49
149.32
149.62
149.42
149.51
114.69
115.73
118.27
139.38
2
were recorded on Mercury-400 and Varian-VXR spec-
trometers using tetramethylsilane as internal reference.
The 13C NMR spectra and two-dimensional spectra
were measured on a Mercury-400 spectrometer. The
progress of reactions and the purity of products were
monitored by TLC on Silufol UV-254 plates using di-
ethyl ether as eluent (development with iodine vapor).
(1H, anti-7-H, J = 8.4 Hz), 1.30 d (1H, syn-7-H),
1.39 d.d.d (1H, endo-5′-H), 1.48 m (1H, endo-2-H),
1.54 m (1H, endo-6′-H), 1.88 m (1H, endo-3′-H),
1.94 m (1H, exo-5′-H), 2.05 t (1H, 4′-H), 2.31 d.d (1H,
exo-3′-H), 2.37 m (1H, exo-6′-H), 2.71 br.s (1H, 1-H),
2.79 br.s (1H, 4-H), 2.89 d (1H, 10′-HB, 2J = 14.9 Hz),
2.94–3.13 m (2H, 8-H), 3.30 d (1H, 10′-HA), 6.07 d.d
(1H, 6-H), 6.11 d.d (1H, 5-H), 7.09 t (1H, NH). Found,
%: C 64.16; H 8.12; N 4.09. C18H27NO3S. Calculated,
%: C 64.06; H 8.06; N 4.15.
Camphor-10-sulfonamides VI–X (general proce-
dure). A solution of 0.40 g (1.6 mmol) of camphor-10-
sulfonyl chloride [17] in 8 ml of chloroform was added
dropwise under stirring to a mixture of 1.6 mmol of
amine IVa–IVe and 0.16 g (0.225 ml, 1.6 mmol) of
triethylamine in 5 ml of chloroform, and the mixture
was stirred at room temperature until the initial com-
pound disappeared according to the TLC data. The
solvent was distilled off, the residue was washed with
10 ml of 5% hydrochloric acid, and the product was
purified by recrystallization from diethyl ether or
propan-2-ol.
N-(Bicyclo[2.2.1]hept-5-en-endo-2-ylmethyl)-
(7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)-
methanesulfonamide (VII) [33]. Yield 75%, mp 94–
95°C, Rf 0.91 (diethyl ether). IR spectrum, ν, cm–1:
3300, 3072, 1741, 1335, 1154, 730. 1H NMR spectrum
(400 MHz, DMSO-d6), δ, ppm: 0.49 d (1H, endo-3-H),
0.79 s (3H, syn-CH3), 1.01 s (3H, anti-CH3), 1.22 d
(1H, anti-7-H), 1.33 d (1H, syn-7-H), 1.39 d.d (1H,
endo-5′-H), 1.51 m (1H, endo-6′-H), 1.79 d.d.d (1H,
exo-3-H), 1.91 m (1H, endo-3′-H), 1.94 m (1H, exo-
5′-H), 2.04 t (1H, 4′-H), 2.18 m (1H, 2-H), 2.33 d.d
(1H, exo-3′-H), 2.36 m (1H, exo-6′-H), 2.61 m (1H,
8-HA), 2.72 m (1H, 8-HB), 2.76 m (1H, 4-H), 2.84 br.s
(1H, 10′-HA), 2.86 s (1H, 1-H), 3.26 m (1H, 10′-HB),
5.97 d.d (1H, 6-H), 6.16 d.d (1H, 5-H), 7.03 t (1H,
NH). 13C NMR spectrum (100.7 MHz, DMSO-d6), δC,
ppm: 20.0, 20.2 (C8′, C9′), 25.2 (C6′), 27.0 (C5′), 30.5
N-(Bicyclo[2.2.1]hept-5-en-exo-2-ylmethyl)-
(7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)-
methanesulfonamide (VI). Yield 65%, mp 89–91°C,
Rf 0.92 (diethyl ether). IR spectrum, ν, cm–1: 3300,
1
3072, 1741, 1335, 1154, 730. H NMR spectrum
(300 MHz, DMSO-d6), δ, ppm: 0.80 s (3H, syn-CH3),
1.03 s (3H, anti-CH3), 1.19–1.14 m (2H, 3-H), 1.23 d
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 7 2009

CAGE-LIKE AMINES IN THE SYNTHESIS AND OXIDATION OF CAMPHOR-10-SULFONIC
1015
(C3), 39.6 (C2), 42.7 (C3′, C4′), 42.8 (C4), 44.3 (C1),
47.4 (C8), 48.1 (C10′), 48.2 (C7′), 49.6 (C7), 58.5 (C1′),
133.0 (C6), 137.8 (C5), 215.4 (C2′). Found, %: C 64.00;
H 8.14; N 4.25. C18H27NO3S. Calculated, %: C 64.06;
H 8.06; N 4.15.
(1H, exo-3-H), 2.62 m (1H, exo-6-H), 2.77 d (1H,
8-HB, J = 14.7 Hz), 2.93 m (1H, CH), 3.33 d (1H,
8-HA), 7.81 br.s (1H, NH). Found, %: C 67.21; H 8.88;
N 3.64. C22H35NO3S. Calculated, %: C 67.14; H 8.96;
N 3.56.
2
N-[(7,7-Dimethyl-2-oxobicyclo[2.2.1]heptan-1-
yl)methylsulfonyl]-4-azatricyclo[4.2.1.03,7]nonan-
exo-2-ol (XIII) was synthesized by oxidation of com-
pound VII according to the procedure described in
[33]. Yield 67%, oily substance, Rf 0.74 (diethyl ether).
IR spectrum, ν, cm–1: 3500, 1755, 1341, 1164, 855.
1H NMR spectrum (300 MHz, CDCl3), δ, ppm: 0.89 s
(3H, syn-CH3), 1.00 m (1H, endo-9-H), 1.13 s (3H,
anti-CH3), 1.44 m (2H, anti-8-H, endo-5′-H), 1.64 m
(1H, endo-6′-H), 1.92 m (2H, syn-8-H, exo-9-H),
1.96 d (1H, endo-3′-H), 2.05 m (1H, exo-5′-H), 2.11 m
(1H, 4′-H), 2.19 br.s (1H, 1-H), 2.36 br.s (2H, 6-H,
exo-3-H), 2.51 m (1H, exo-6′-H), 2.68 m (1H, 7-H),
2.84 d.d (1H, 10′-HA), 3.28 m (1H, 5-HA), 3.40 m (1H,
5-HB), 3.48 m (1H, 10′-HB), 3.61 d (1H, 3-H), 3.71 br.s
(1H, 2-H). 13C NMR spectrum (100.7 MHz, CDCl3),
δC, ppm: 20.0, 20.2 (C8′, C9′), 25.4 (C6′), 27.2 (C5′),
33.0 (C9), 34.1 (C8), 37.2 (C6), 41.6 (C1), 42.9 (C10′),
43.0 (C4′), 45.2 (C7), 46.1 (C3′), 48.2 (C7′), 54.6 (C5),
58.5 (C1′), 69.5 (C3), 81.5 (C2), 216.0 (C=O). Found,
%: C 61.25; H 7.61; N 4.09. C18H27NO4S. Calculated,
%: C 61.16; H 7.70; N 3.96.
(7,7-Dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)-
N-(exo-5,6-epoxybicyclo[2.2.1]hept-exo-2-ylmethyl)-
methanesulfonamide (VIII). a. Yield 61%, mp 96–
97°C, Rf 0.79 (diethyl ether). IR spectrum, ν, cm–1:
3315, 2980, 1752, 1340, 1157, 855. 1H NMR spectrum
(300 MHz, DMSO-d6), δ, ppm: 0.79 d (1H, anti-7-H,
2J = 10.6 Hz), 0.80 s (3H, syn-CH3), 1.02 s (3H, anti-
CH3), 1.05 d (1H, syn-7-H), 1.17 m (1H, endo-3-H),
1.38 m (1H, exo-3-H), 1.43 m (1H, endo-5′-H), 1.52 m
(1H, endo-6′-H), 1.63 m (1H, endo-2-H), 1.88 m (1H,
endo-3′-H), 1.94 m (1H, exo-5′-H), 2.03 t (1H, 4′-H),
2.30 m (1H, exo-3′-H), 2.35 m (1H, exo-6′-H),
2.37 br.s (1H, 4-H), 2.49 br.s (1H, 1-H), 2.88 d (1H,
2
10′-HB, J = 15.0 Hz), 2.85–2.91 m (2H, 8-H), 3.08 d
3
(1H, 6-H), 3.12 d (1H, 5-H, J5,6 = 3.8), 3.29 d (1H,
10′-HA), 7.07 t (1H, NH). Found, %: C 61.08; H 7.79;
N 4.05. C18H27NO4S. Calculated, %: C 61.16; H 7.70;
N 3.96.
b. Sulfonamide VI, 0.75 g (2.2 mmol), urea, 0.06 g
(1.1 mmol), and phthalic anhydride, 0.66 g (4.4 mmol),
were dispersed in 10 ml of ethyl acetate, and 0.44 g
(6.7 mmol) of 50% hydrogen peroxide was added
under stirring. The mixture was stirred until the reac-
tion was complete (TLC) and treated with a saturated
solution of sodium carbonate. The organic phase was
separated, the aqueous phase was extracted with three
portions of chloroform, the extracts were combined
with the organic phase and dried over calcined magne-
sium sulfate, and the solvent was removed under
reduced pressure. Yield 69%.
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