New NO donors with antithrombotic and vasodilating activities, Part 29. N-(1-cyanocyclohexyl)-C-phenylnitrones and glyoxaldinitrones.

Article abstract of DOI:10.1002/(SICI)1521-4184(20005)333:5<130::AID-ARDP130>3.0.CO;2-D

Six N-(1-cyanocyclohexyl)-C-phenylnitrones 4a-f (4b-f for the first time) and 22 glyoxaldinitrones 7a-v were prepared and tested for antithrombotic (p.o. administration to rats, 60 mg/kg) effects. Both classes of compounds exhibit considerable antithrombo

Full text of DOI:10.1002/(SICI)1521-4184(20005)333:5<130::AID-ARDP130>3.0.CO;2-D

130
Camehn and Rehse
New NO Donors with Antithrombotic and Vasodilating Activities, Part 29
N-(1-Cyanocyclohexyl)-C-phenylnitrones and Glyoxaldinitrones✩
1)
Rainer Camehn and Klaus Rehse*
Institut für Pharmazie, Freie Universität Berlin, Königin-Luise-Str. 2+4, D-14195 Berlin, Germany
Key Words: N-(1-Cyanocyclohexyl)-C-phenylnitrones; glyoxaldinitrones; antithrombotic properties; nitric oxide;
cyp 450 surrogate
Summary
Six N-(1-cyanocyclohexyl)-C-phenylnitrones 4a–f (4b–f for the
first time) and 22 glyoxaldinitrones 7a–v were prepared and tested
for antithrombotic (p.o. administration to rats, 60 mg/kg) effects.
Both classes of compounds exhibit considerable antithrombotic
activities. Maximum inhibition of thrombus formation in arterioles
(21%) was observed in N,N′-bis-2-phenylethylglyoxaldinitrone
(7o) and N,N′-bis-4-nitrobenzylglyoxaldinitrone (7u). The com-
pounds form only small amounts of nitric oxide in vitro by the
addition of a Fe3+-porphyrine complex and an oxygen donor.
Introduction
To date no antithrombotic activities of nitrones have been
reported. However, in vitro production of nitric oxide from
phenyl-N-tert-butylnitrone (pbn) and activation of guanyl-
atecyclase by pbn were reported in 1993 . Konorev et al.
Figure 1. Synthesis of N-(1-cyanocyclohexyl)-C-phenylnitrones (4) from
α-hydroxylamino nitriles (3) and glyoxaldinitrones (7) obtained from hy-
droxylamines (6) by the reduction of oximes (5) with diborane.
[1]
[2]
in the same year reported vasodilating properties of pbn. This
prompted us to investigate thoroughly the antithrombotic
properties of nitrones. We recently reported that in pyrazol-
[3]
4-one-1,2-dioxides (1) antithrombotic activities are en-
The first step in the synthesis of 4 is the formation of
[7]
hanced by electron withdrawing groups near the NO group.
Furthermore, it was found that azodioxides with a geminal
α-hydroxylaminonitrile (3) . The reaction with different
aldehydes leads to the desired nitrones 4.
cyano group (2) show antithrombotic activity and are able to
Glyoxaldinitrones (7) were prepared from the correspond-
ing hydroxylamines (6) which in general were obtained by
[4]
form high amounts of NO by spontaneous decomposition
.
[8]
Therefore, first of all derivatives of pbn with electron with-
the reduction of oximes (5) with diborane (which was
[9]
drawing moieties were tested. From previous investiga-
obtained by the method of Hach ).
[5,6]
tions
we knew the suitability of doubling the NO moiety.
Compounds 7a, b, d, and 7e were prepared by the method
[10]
Therefore, we prepared glyoxaldinitrones (7) in order to
strengthen the above pharmacological effects.
of Zinner et al. . Hydroxylamines were obtained from
[7]
cyclohexanone (7a), by the reduction of nitro compounds
(7d,e), or purchased from Aldrich (7b).
Biology
Antithrombotic Properties
The influence of the test compounds on the formation of
[11]
thrombi was assayed in a laser thrombosis model . The title
compounds were administered orally to rats (60 mg/kg). Af-
ter 2 h the formation of thrombi in mesenteric vessels of rats
is induced by the beam of an argon laser via a microscope
(35 mW, 50 ms). The number of exposures (“shots”) neces-
sary to form a thrombus of defined size is counted. From the
average shot number the percentage of inhibition of throm-
Chemistry
N-(1-cyanocyclohexyl)-C-phenylnitrones (4) and glyox-
aldinitrones (7) were prepared according to Figure 1.
———
1) Part of the PhD Thesis of R. Camehn, FU Berlin, 1999.
[12]
bosis is calculated . The results are compiled in Table 1.
Arch. Pharm. Pharm. Med. Chem.
© WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
0365-6233/00/0505/0130 $17.50 +.50/0

NO Donors with Antithrombotic, Vasodilating Activities
131
Table 1. Antithrombotic effects of N-(1-cyanocyclohexyl)-C-phenylni-
trones (4) and glyoxaldinitrones (7) or acetylsalicyclic acid (asa), 2 h after
p.o. administration of 60 mg/kg of the test compound. Statistics: Man-Whit-
ney U-test: n.s. = not significant.
In general, glyoxaldinitrones exhibit a moderate (≥ 10%)
inhibition of thrombosis in arterioles. The effects in venules
are weaker. This is not surprising because it is more difficult
[13]
to inhibit the formation of thrombi in venules . In the
——————————————————————————————
N-(1-cyanocyclohexyl)-C-phenylnitrones (4) the results pre-
sent a mixed picture. Substitution of the phenyl ring by the
electron donating dimethylamino group (4b) gave an inactive
Inhibition of thrombus formation in
No.
R
arterioles
venules
[14]
———————
———————
nitrone, probably due to a more stable compound . The
% ± sx
p ≤
% ± sx
p ≤
compounds with electron withdrawing nitro (4e) or tri-
fluoromethyl (4f) substituents showed antithrombotic effects
in the order of the unsubstituted phenyl one (4a). Most
surprisingly, the 4-chloro (4c) and 4-cyano (4d) derivatives
were inactive, so that the electronic effect is not determining
the antithrombotic effect. In the class of glyoxaldinitrones
(7a–v) most of the compounds showed antithrombotic activi-
ties in arterioles and to a smaller extent also in venules. The
biscyanocyclohexyl derivative 7a had been synthesized in
analogy to the mono nitrone 4a and because of good experi-
ence relating to antithrombotic effects with this cyanocyclo-
——————————————————————————————
4a
4b
4c
4d
4e
4f
H
13 ± 1
0 ± 1
0.002
n.s.
10 ± 1
0 ± 1
0 ± 1
1 ± 1
6 ± 1
8 ± 1
0.002
n.s.
N(CH3)2
Cl
0 ± 1
n.s.
n.s.
CN
4 ± 1
0.2
n.s.
NO2
CF3
12 ± 1
17 ± 1
0.002
0.002
0.02
0.002
[4]
hexyl moiety . It showed a small but significant anti-
thrombotic effect. Surprisingly, 7b which lacks the cyano
group was even more active, indicating that cyano substitu-
tion is not essential and suggesting that the lipophilicity and
membranotropic properties might play a role. We therefore
prepared 7c–7k. It was surprising that the ethyl derivative 7d
already showed considerable antithrombotic properties even
7a
7b
7c
7d
7e
7f
1-CN-cyclohexyl
cyclohexyl
CH3
9 ± 1
14 ± 2
9 ± 1
0.002
0.002
0.002
0.002
0.002
0.01
6 ± 1
9 ± 1
6 ± 1
11 ± 1
8 ± 2
5 ± 1
8 ± 1
11 ± 1
7 ± 1
6 ± 1
0 ± 1
1 ± 1
0.01
0.002
0.02
in venules. The results in 7g–7j were in accordance with
C2H5
16 ± 1
11 ± 1
7 ± 1
0.002
0.002
0.01
[13,15,16]
former results
in other classes ofantithrombotic com-
pounds. The maximum activity in the hexyl derivative (7h)
is also typical. The same is true in the series of 7m–7p where
the strongest effect is found in the 2-phenylethyl derivative
7o. This substituent corresponds to a chain length of six
carbon atoms. Compounds 7q–7v were synthesized to inves-
tigate the influence of electron donating or electron accepting
substituents in the phenyl ring. Comparison with the unsub-
stituted aromatic ring (7n) shows that this alteration is of
minor importance. Only a nitro group in 4-position enhances
the antithrombotic effect. This group in 2-position however
decreases the activity indicating that steric requirements are
more important than electronic ones.
C3H7
C4H9
7g
7h
7i
C5H11
13 ± 1
20 ± 1
10 ± 1
13 ± 2
1 ± 2
0.002
0.002
0.002
0.002
n.s.
0.002
0.002
0.002
0.01
C6H13
C7H15
7j
C8H17
7k
7l
C10H21
n.s.
CH2-cyclohexyl
4 ± 1
0.05
n.s.
In Vitro Formation of Nitric Oxide
7m
7n
7o
7p
7q
7r
Ph
7 ± 1
15 ± 2
21 ± 1
13 ± 1
13 ± 1
10 ± 1
13 ± 1
14 ± 1
21 ± 1
7 ± 1
0.01
3 ± 1
11 ± 1
13 ± 1
9 ± 1
0.2
[1]
CH2-Ph
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.02
0.002
0.002
0.002
0.002
0.01
The in vitro release of NO from pbn was reported. How-
ever, no formation of NO from N-(1-cyanocyclohexl)-C-
phenylnitrones and glyoxaldinitrones hitherto has been
stated. The formation of nitric oxide was determined by the
C2H4-Ph
C3H6-Ph
[17]
method of Duchstein and Riederer . Briefly the spontane-
CH2-Ph-4-CH3
CH2-Ph-4-OCH3
CH2-Ph-4-Cl
CH2-Ph-4-CF3
CH2-Ph-4-NO2
CH2-Ph-2-NO2
9 ± 1
ous release of nitric oxide is checked in argon atmosphere
(anaerobic, method A, 28 min). The release of NO is meas-
7 ± 1
[17]
ured by chemiluminescence . The results are compiled in
7s
8 ± 1
0.002
0.002
0.002
0.05
the 2nd column of Table 2. In contrast, the oxidative forma-
[18]
tion of nitric oxide from nitrones by liver cells is mimicked
7t
9 ± 1
3+
in vitro by the addition of an Fe -porphyrin complex (as
cytochrome surrogate) and an oxygen donor, i.e. (bis-tri-
fluoroacetoxy)iodobenzene, to the ethanolic solutions of se-
lected compounds (aerobic, method B). The results are
summarized in the 3rd column of Table 2. For this purpose
were chosen 7d, 7h, 7o, and 7u which had shown the highest
antithrombotic activity. For comparison the inactive pbn (in
7u
7v
asa
15 ± 1
4 ± 1
48 ± 10 0.002
20 ± 5
0.01
——————————————————————————————
Arch. Pharm. Pharm. Med. Chem. 333, 130–134 (2000)

132
Camehn and Rehse
Table 2. In vitro formation of NO from 3 mol of pbn, 7d, h, o, and 7u (n = 3)
or SIN 1 in ethanol within 28 min at 37 °C.
1-[N-(4-Dimethylamino-phenylmethylene)]aminocyclohexanecarbonitrile
N-Oxide (4b)
——————————————————————————————
From 1.5 g (0.01 mol) 4-dimethylaminobenzaldehyde. Colorless crystals
(petroleum ether), mp 151 °C, yield 0.8 g (26%).– Anal.– IR (KBr): ν = 3077
cm–1; 2245 (CN); 1604 (C=N); 1104 (NO).– 1H-NMR/400 MHz ([D6]
DMSO): d (ppm) = 1.23–2.26 (m, 8H, cyclohexyl-2H-6H-(only eq.)-3H-4H-
5H), 2.42 (“d”, J = 12.5 Hz, 2H, cyclohexyl-2H-6H (ax.)), 2.99 (s, 6H, 2 ×
CH3), 6.73 (“d”, J = 9.0 Hz, 2H, aromat.-3H-5H), 7.77 (s, 1H, N=CH), 8.21
(“d”, J = 9.0 Hz, 2H, aromat.-2H-6H).– MS (70 eV): m/z (%) = 271 (35)
[M+], 254 (12) [M+–OH], 108 (53) [C7H10N+], 81 (100) [108+–HCN], 41
(38) [C3H5+].
A
B
Compound
nmol NO
± SD
nmol NO
± SD
——————————————————————————————
pbn
7d
1.92 ± 0.05
0.0
1.99 ± 0.09
1.02 ± 0.06
0.93 ± 0.06
4.32 ± 0.39
1.72 ± 0.05
0.46 ± 0.03
1-[N-(4-Chlorophenylmethylene)]aminocyclohexanecarbonitrile N-Oxide
(4c)
7h
1.12 ± 0.02
3.44 ± 0.12
1.59 ± 0.15
4.80 ± 0.2
7o
From 1.4 g (0.01 mol) 4-chlorobenzaldehyde. Yellowish crystals (petro-
7u
leum ether), mp 117 °C, yield 0.4 g (15%).– Anal. C14H15N2OCl IR
1
(KBr):ν = 3163 cm–1; 2248 (CN); 1123 (NO).– H-NMR/400 MHz ([D6]
SIN 1
DMSO): δ (ppm) =1.25–2.20 (m, 8H, cyclohexyl-2H-6H-(only eq.)-3H-4H-
5H), 2.49 (“d”, J = 12.5 Hz, 2H, cyclohexyl-2H-6H (ax.)), 7.60 (“d”, J = 8.2
Hz, 2H, aromat.-3H-5H), 8.18 (s, 1H, N=CH), 8.45 (“d”, J = 8.7 Hz, 2H,
aromat.-2H-6H).– MS (70 eV): m/z (%) = 262 (36) [M+], 245 (63) [M+–OH],
108 (66) [C7H10N+], 81 (100) [108+–HCN], 41 (39) [C3H5+].
——————————————————————————————
1)
vivo data not shown and the well known NO donor SIN 1
were included.
The results from methods A and B show that only small
amounts of NO are formed under both conditions. The NO-
formation in 7d, 7o, and 7u is enhanced a little in the presence
of an oxygen donor (method B). It is obvious that in SIN 1
the detection of NO is decreased when oxidative reaction
conditions are used. The reason is that in nitrones the N-O
nitrogen has the oxidation number –1 while in SIN 1 it is +2
(after opening of the sydnone ring) like in NO itself. This
explains why oxidation generally enhances NO formation in
type 7 compounds. Consequently in SIN 1 the detected
amount of NO is decreased by further oxidation to nitrite.
However, the in vivo results from the thrombosis model do
not correlate with the in vitro oxidative formation. This
indicates that the cleavage of the nitrones in vivo could be a
necessity for their activity. SIN 1 obviously is stable under
either in vitro conditions. Nevertheless, these data provide no
evidence that the antithrombotic effects are related to nitric
oxide formation.
1-[N-(4-Cyanophenylmethylene)]aminocyclohexanecarbonitrile N-Oxide
(4d)
From 1.3 g (0.01 mol) 4-cyanobenzaldehyde. Colorless crystals (petro-
leum ether), mp 150 °C, yield 0.5 g (20%).– Anal.– IR (KBr): ν = 3425 cm–1
;
2224 (CN); 1129 (NO).– 1H-NMR/400 MHz ([D6] DMSO): δ (ppm) =
1.28–2.27 (m, 8H, cyclohexyl-2H-6H-(only eq.),-3H-4H-5H), 2.52 (“d”, J =
12.7 Hz, 2H, cyclohexyl-2H-6H (ax.)), 7.99 (“d”, J = 8.3 Hz, 2H, aromat.-
3H-5H), 8.31 (s, 1H, N=CH), 8.56 (“d”, J = 8.4 Hz, 2H, aromat.-2H-6H).–
MS (70 eV): m/z (%) = 253 (33) [M+], 236 (43) [M+–OH], 108 (79)
[C7H10N+], 81 (100) [108+–HCN], 41 (47) [C3H5+].
1-[N-(4-Nitrophenylmethylene)]amino-cyclohexanecarbonitrile N-Oxide
(4e)
From 1.5 g (0.01 mol) 4-nitrobenzaldehyde. Yellowish leaves (petroleum
ether), mp 154 °C, yield 0.7 g (26%).– Anal. C14H15N3O3 – IR (KBr): ν =
3104 cm–1; 2220 (CN); 1136 (NO).– 1H-NMR/400 MHz ([D6] DMSO): δ
(ppm) = 1.32–2.29 (m, 8H, cyclohexyl-2H-6H-(only eq.),-3H-4H-5H), 2.53
(“d”, J = 12 Hz, 2H, cyclohexyl-2H-6H (ax.)), 8.38–8.40 (m, 3H, aromat.-
3H-5H and N=CH), 8.65 (“d”, J = 8.9 Hz, 2H, aromat.-2H-6H).– MS
(70 eV): m/z (%) = 273 (11) [M+], 256 (17) [M+–OH], 108 (57) [C7H10N+],
81 (100) [108+–HCN], 41 (39) [C3H5+].
Experimental Part
1)
Chemistry
1-[N-(4-Trifluoromethyl-phenylmethylene)]aminocyclohexanecarbonitrile
N-Oxide (4f)
Mp (uncorr.), Lindström.– Elemental analysis: Elementar VarioEL.– IR:
ATI Mattson Genenis Serie FTIR.– UV/VIS: Kontron Instruments UVIKON
930.– NMR: Bruker AC 300 and DPX 400.– 70 eV-MS: Varian MAT CH7
A and Kratos MS 25 RF.-FAB-MS:Varian MAT CH5-DF.
The synthesis of 4a[19], 7c, 7n[10], and 7m[20] has been reported in the
literature.
From 1.7 g (0.01 mol) 4-trifluoromethylbenzaldehyde. Colorless crystals
(ethanol), mp 119 °C, yield 0.6 g (20%).– Anal. C15H15N2OF3.– IR (KBr):
ν = 3158 cm–1; 2244 (CN); 1577 (C=N); 1329 (C-F); 1126 (NO).– 1H-
NMR/400 MHz ([D6] DMSO): δ (ppm) =1.26–2.33 (m, 8H, cyclohexyl-2H-
6H-(only eq.),-3H-4H-5H), 2.46 (“d”, J = 12.5 Hz, 2H, cyclohexyl-2H-6H
(ax.)), 7.85 (“d”, J = 8.3 Hz, 2H, aromat.-3H-5H), 8.25 (s, 1H, N=CH), 8.55
(“d”, J = 8.3 Hz, 2H, aromat.-2H-6H).– 13C-NMR/400 MHz ([D6] DMSO):
δ (ppm) = 24.8 (cyclohexyl-C-3 and C-5), 25.3 (cyclohexyl-C-4), 35.8
(cyclohexyl-C-2 and C-6), 76.9 (NC-C-NO), 119.4 (CN), 124.2 (CF3), 127.0
(Ph-C-3 and C-5), 131.0 (Ph-C-2 and C-6), 131.6 (Ph-C-4), 131.9 (ON=C),
135.5 (Ph-C-1).– MS (70 eV): m/z (%) = 296 (30) [M+], 279 (39) [M+–OH],
108 (75) [C7H10N+], 81 (100) [108+–HCN], 41 (38) [C3H5+].
General Procedure for the Synthesis of 4
Method of Thesing [21]: 10.0 mmol of the α-hydroxylaminonitrile 3 (pre-
pared by the method of Neelakantan and Hartung[7]) and an equal amount of
aldehyde in 30 ml toluene were heated at 70 °C for 1.5 h. After water from
the reaction has been distilled off azeotropically, the solvent is removed and
oily residue deposited in the refrigerator for crystallization. The products
were generally recrystallized from ethanol or petroleum ether (exceptions are
noted).
General Procedure for the Synthesis of 7
———
Glyoxaldinitrones(7) were prepared from the corresponding hydroxylami-
nes (6) which in general were obtained by the reduction of oximes (5) with
diborane[8] (production of diborane modified by the method of Hach[9]).
1)
The full set of data is given in the PhD thesis of R. Camehn, Freie
Universität Berlin 1999.
Arch. Pharm. Pharm. Med. Chem. 333, 130–134 (2000)

NO Donors with Antithrombotic, Vasodilating Activities
133
All equipment to be used is oven-dried. The starting aldoxime (20 mmol)
is placed in a flask equipped with a magnetic stirrer, calcium chloride tube,
nitrogen inlet, and dropping funnel. Sodium borohydride (40 mmol, 1.51 g)
is placed in the flask and tetrahydrofuran (75 ml) is added at once. The
temperature is kept at 0 °C. The flask is placed in a water-ice bath and a
solution of acetic acid (40 mmol) is added carefully (temperature is kept in
the 10–20 °C range). After the addition of the solution is completed, the
reaction mixture is stirred for 4 h at ambient temperature, removing the
solvent in vacuo, and lowering the temperature to 0 °C was followed by the
addition of 10 ml of 20% hydrochloric acid by means of a syringe, at such a
rate that the temperature did not exceed 5 °C. The reaction mixture was
refluxed for 1 h. Lowering the temperature to 50 °C was followed by the
addition of 15 mmol glyoxal. The glyoxaldinitrones precipitated spontane-
ously or after few days under refrigeration. The compounds generally recrys-
tallized from ethanol or ethanol/petroleum ether (exceptions are noted).
Compounds 7a, b, d, and 7e were prepared by the method of Zinner et
al.[10]. Compounds 7a, d, e were prepared from hydroxylamines which were
obtained from cyclohexanone[7](7a) or by the reduction of nitro compounds
(7 d,e). The hydroxylamine for 7b was purchased from Aldrich..
N=CH-CH=N).– MS (70 eV): m/z (%) =200 (7) [M+], 183 (9) [M+–OH], 45
(100) [C2H7N+], 43 (9) [C3H7+], 41 (34) [C3H5+].
Ethanediylidenediamine-dipentane N,N′-Dioxide (7g)
From 2.0 g (0.02 mol) pentanal oxime. Light greenish crystals (ethanol/pe-
troleum ether), mp 113 °C (dec.), yield 1.5 g (65%).– Anal. C12H24N2O2.–
IR (KBr): ν = 3103 cm–1; 1532 (C=N); 1157 (NO); 1123 (NO).– 1H-
NMR/400 MHz (CDCl3): δ (ppm) = 0.91 (t, J = 6.9 Hz, 6H, 2 × CH3),
1.31–1.38 (m, 8H, 2 × (CH2)2-CH3), 1.92 (tt, J = 6.9/ 7.1 Hz, 4H, 2 ×
N-CH2-CH2), 3.87 (t, J = 6.9 Hz, 4H, 2 × N-CH2-), 7.81 (s, 2H, N=CH-
CH=N).– MS (70 eV): m/z (%) =228 (8) [M+], 211 (15) [M+–OH], 71 (20)
[C5H11+], 55 (13) [C4H7+], 43 (100) [C3H7+], 41 (49) [C3H5+], 30 (12).
Ethanediylidenediamine-dihexane N,N′-Dioxide (7h)
From 2.3 g (0.02 mol) hexanal oxime. Light greenish crystals (toluene),
mp 141 °C (dec.), yield 1.7 g (64%).– Anal. C14H28N2O2.– IR (KBr): ν =
3103 cm–1; 1531 (C=N); 1157 (NO); 1126 (NO).– 1H-NMR/400 MHz ([D6]
DMSO): δ (ppm) = 0.85 (t, J = 6.8 Hz, 6H, 2 × CH3), 1.12–1.39 (m, 12H, 2
× hexyl-(CH2)3-CH3), 1.72 (tt, J = 6.8/ 6.8 Hz, 4H, 2 × N-CH2-CH2), 3.87
(t, J = 6.8 Hz, 4H, 2 × N-CH2-), 7.91 (s, 2H, N=CH-CH=N).– MS (70 eV):
m/z (%) =256 (11) [M+], 239 (24) [M+–OH], 85 (25) [C6H13+], 55 (27)
[C4H7+],43 (100) [C3H7+], 41 (40) [C3H5+].
Ethanediylidenediamine-bis(1-cyclohexanecarbonitrile) N,N′-Dioxide (7a)
From 1.4 g (0.01 mol) 1-hydroxyamino-cyclohexanecarbonitrile[7] (3).
Light greenish crystals (ethanol), mp 206 °C, yield 0.9 g (21%).– Anal.– IR
(KBr): ν = 3138 cm–1; 2245 (CN); 1511 (C=N); 1171 (NO); 1134 (NO).–
1H-NMR/400 MHz ([D6] DMSO): δ (ppm) = 1.12–2.21 (m, 16H, 2 ×
cyclohexyl-2H-6H-(only eq.),-3H-4H-5H), 2.35 (“d”, J = 13 Hz, 4H, 2 ×
cyclohexyl-2H-6H (ax.)), 8.12 (s, 2H, N=CH-CH=N).–MS (70 eV): m/z (%)
= 302 (12) [M+], 285 (9) [M+–OH], 108 (87) [C7H10N+], 81 (100) [108+–
HCN], 41 (50) [C3H5+], 39 (18).
Ethanediylidenediamine-diheptane N,N′-Dioxide (7i)
From 2.6 g (0.02 mol) heptanal oxime. Greenish crystals (ethanol/petro-
leum ether), mp 145 °C (dec.), yield 1.5 g (51%).– Anal. C16H32N2O2.– IR
(KBr): ν = 3104 cm–1; 1532 (C=N); 1157 (NO); 1124 (NO).– 1H-NMR/400
MHz (CDCl3): δ (ppm) = 0.88 (t, J = 6.9 Hz, 6H, 2 × CH3), 1.26–1.32 (m,
16H, 2 × Heptyl-(CH2)4-CH3), 1.92 (tt, J = 7.0/ 7.0 Hz, 4H, 2 × N-CH2-CH2),
3.85 (t, J = 7.1 Hz, 4H, 2 × N-CH2-), 7.79 (s, 2H, N=CH-CH=N).– MS
(70 eV): m/z (%) = 284 (11) [M+], 267 (42) [M+–OH], 85 (18) [C6H13+], 57
(100) [C4H9+], 55 (54) [C4H7+], 43 (74) [C3H7+], 41 (81) [C3H5+], 30 (15).
Ethanediylidenediamine-dicyclohexane N,N′-Dioxide (7b)
From 1.2 g (0.01 mol) N-cyclohexylhydroxylamine-HCl. Colorless crys-
tals (ethanol), mp 230 °C, yield 0.3 g (16%).– Anal.– IR (KBr): ν = 3094
cm–1; 1525 (C=N); 1159 (NO); 1144 (NO).– 1H-NMR/400 MHz (CDCl3):
δ (ppm) = 1.14–2.16 (m, 20H, 2 × cyclohexyl-2H-3H-4H-5H-6H), 3.70–3.96
(m, 2H, 2 × cyclohexyl-1H-(ax.)), 7.85 (s, 2H, N=CH-CH=N).– 13C-
NMR/400 MHz (CDCl3): δ (ppm) = 25.3 (2 × cyclohexyl-C-3-C-4-C-5),
31.5 (2 × cyclohexyl-C-2-C-6),77.1 (2 × cyclohexyl-C-1), 127.0 (N=C-
C=N).– MS (70 eV): m/z (%) = 252 (12) [M+], 235 (12) [M+–OH], 108 (5)
[C7H10N+], 83 (64) [C6H11+], 55 (100) [C4H9+], 41 (63) [C3H5+], 39 (14).
Ethanediylidenediamine-dioctane N,N′-Dioxide (7j)
From 2.8 g (0.02 mol) octanal oxime. Yellowish-greenish crystals (etha-
nol/petroleum ether), mp 152 °C (dec.), yield 2.3 g (42%).– Anal.
C18H36N2O2.– IR (KBr): ν = 3104 cm–1; 1533 (C=N); 1157 (NO); 1123
(NO).– 1H-NMR/400 MHz (CDCl3): δ (ppm) = 0.88 (t, J = 6.8 Hz, 6H, 2 ×
CH3), 1.27–1.32 (m, 20H, 2 × Octyl-(CH2)5-CH3), 1.91 (tt, J = 7.1/7.1 Hz,
4H, 2 × N-CH2-CH2), 3.89 (t, J = 7.1 Hz, 4H, 2 × N-CH2-), 7.86 (s, 2H,
N=CH-CH=N).– MS (70 eV): m/z (%) =312 (19) [M+], 295 (64) [M+–OH],
85 (73) [C6H13+], 83 (19) [C6H11+], 81 (17), 71 (100) [C5H11+], 55 (52)
[C4H7+], 43 (99) [C3H7+], 41 (66) [C3H5+], 30 (23).
Ethanediylidenediamine-diethane N,N′-Dioxide, (1,2-bis(ethylimino)ethane
N,N′-Dioxide) (7d)
From 6.1 g (0. 1 mol) N-ethylhydroxylamine. Colorless leaves (ethanol),
mp 150 °C (dec.), yield 0.5 g (7%).– Anal. C6H12N2O2.– IR (KBr): ν = 3099
cm–1; 1531 (C=N); 1159 (NO); 1122 (NO).– 1H-NMR/400 MHz ([D6]
DMSO): δ (ppm) = 1.29 (t, J = 7.1 Hz, 6H, 2 × CH3), 3.90 (q, J = 7.1 Hz,
4H, 2 × N-CH2-CH3), 7.91 (s, 2H, N=CH-CH=N).– MS (70 eV): m/z (%)
=144 (100) [M+], 127 (19) [M+–OH], 30 (31) [NO+].
Ethanediylidenediamine-didecane N,N′-Dioxide (7k)
From 3.4 g (0.02 mol) decanal oxime. Colorless crystals (toluene), mp
144 °C (dec.), yield 1.1 g (31%).– Anal. C22H44N2O2.– IR (KBr): ν = 3104
cm–1; 1532 (C=N); 1156 (NO); 1123 (NO).– 1H-NMR/400 MHz (CDCl3):
δ (ppm) = 0.88 (t, J = 7.0 Hz, 6H, 2 × CH3), 1.26–1.32 (m, 28H, 2 ×
Decyl-(CH2)6-CH3), 1.91 (“q”, J = 7.0 Hz, 4H, 2 × N-CH2-CH2), 3.90 (t, J
= 7.2 Hz, 4H, 2 × N-CH2-), 7.86 (s, 2H, N=CH-CH=N).– MS (70 eV): m/z
(%) =368 (9) [M+], 351 (42) [M+–OH], 85(25) [C6H13+], 83 (16) [C6H11+],72
(20), 71 (25) [C5H11+], 55 (57) [C4H7+], 43 (100) [C3H7+], 41 (67) [C3H5+].
Ethanediylidenediamine-dipropane N,N′-Dioxide (7e)
From 7.5 g (0.1 mol) N-propylhydroxylamine. Light greenish crystals
(ethanol), mp 153 °C (dec.), yield 0.8 g (9%).– Anal. C8H16N2O2.– IR
(KBr): ν = 3102 cm–1; 1531 (C=N); 1157 (NO); 1122 (NO).– 1H-NMR/400
MHz ([D6] DMSO): δ (ppm) = 0.85 (t, J = 7.3 Hz, 6H, 2 × CH3), 1.75 (qt, J
= 7.1 Hz, 4H, 2 × H3C-CH2-CH2), 3.86 (t, J = 6.8 Hz, 4H, 2 × N-CH2-), 7.91
(s, 2H, N=CH-CH=N).– MS (70 eV): m/z (%) =172 (17) [M+], 155 (11)
[M+–OH], 43 (100) [C3H7+], 41 (48) [C3H5+].
Ethanediylidenediamine-bis(cyclohexylmethane) N,N′-Dioxide (7l)
From 2.5 g (0.02 mol) cyclohexanecarbaldehydeoxime. Greenish leaves
(ethanol), mp 201 °C (dec.), yield 1.5 g (55%).– Anal.– IR (KBr): ν =
3100 cm–1; 1527 (C=N); 1161 (NO); 1141 (NO).– 1H-NMR/400 MHz
(CDCl3): δ (ppm) = 0.93–1.34 (m, 20H, 2 × cyclohexyl-2H-3H-4H-5H-6H),
2.06–2.15 (m, 2H, 2 × cyclohexyl-1H), 3.72 (d, J = 7.2 Hz, 4H, 2 × N-CH2-),
7.80 (s, 2H, N=CH-CH=N).– MS (70 eV): m/z (%) =280(10) [M+], 263 (30)
[M+–OH], 153 (13), 97 (32) [C7H13+], 85 (23) [C6H13+], 55 (100) [C4H7+],
41 (34) [C3H5+].
Ethanediylidenediamine-dibutane N,N′-Dioxide (7f)
From 1.74 g (0.02 mol) butanal oxime. Light greenish leaves (ethanol/
petroleum ether), mp 135 °C (dec.), yield 1.4 g (72%).– Anal. C10H20N2O2.–
IR (KBr): ν = 3102 cm–1; 1532 (C=N); 1157 (NO); 1123 (NO).– 1H-
NMR/400 MHz ([D6] DMSO): δ (ppm) = 0.88 (t, J = 7.3 Hz, 6H, 2 × CH3),
1.26 (qt, J = 7.3/ 7.5 Hz, 4H, 2 × H3C-CH2-CH2), 1.71 (tt, J = 7.0/ 7.2 Hz,
4H, 2 × H3C-CH2-CH2), 3.89 (t, J = 6.8 Hz, 4H, 2 × N-CH2-), 7.91 (s, 2H,
Arch. Pharm. Pharm. Med. Chem. 333, 130–134 (2000)

134
Camehn and Rehse
Ethanediylidenediamine-bis(2-phenylethane) N,N′-Dioxide (7o)
Ethanediylidenediamine-bis(2-nitrophenylmethane)-N,N′-dioxide (7v)
From 2.6 g (0.02 mol) (E/Z)-phenylacetaldehyde oxime. Yellowish leaves
(ethanol), mp 154 °C (dec.), yield 0.8 g (28%).– Anal. C18H20N2O2.– IR
(KBr): ν = 3098 cm–1; 1531 (C=N); 1159 (NO).– 1H-NMR/400 MHz ([D6]
DMSO): δ (ppm) = 3.04 (t, J = 7.1 Hz, 4H, 2 × Ph-CH2-CH2), 4.12 (t, J =
7.1 Hz, 4H, 2 × N-CH2-CH2), 7.20–7.30 (m, 10 H, 2 × Ph), 7.79 (s, 2H,
N=CH-CH=N).– MS (70 eV): m/z (%) =296 (14) [M+], 105 (88), 104 (100)
[C8H8+], 91 (29) [C7H7+], 77 (19) [C6H5+].
From 3.3 g (0.02 mol) 2-nitrobenzaldoxime. Yellowish crystals (chloro-
form), mp 157 °C (dec.), yield 2.3 g (65%).– Anal. C16H14N4O6.– IR (KBr):
ν = 3092 cm–1; 1520 (C=N); 1446; 1434; 1146 (NO).– 1H-NMR/400 MHz
([D6] DMSO): δ (ppm) = 5.48 (s, 4H, 2 × N-CH2-), 7.63–7.67 (m, 4H, 2 ×
Ph-4H-6H), 7.78 (“t”, J = 7.4 Hz, 2H , 2 × Ph-5H), 8.05 (“d”, J = 7.8 Hz, 2H,
Ph-3H), 8.10 (s, 2H, N=CH-CH=N).– MS (70 eV): m/z (%) =358 (2) [M+],
146 (17), 136 (38) [C7H7-NO2+], 135 (35), 91 (36), 89 (29), 79 (34), 78 (100)
[C6H6+], 77 (52), 76 (43), 75 (14), 74 (12), 38 (47), 30 (27) [NO+].
Ethanediylidenediamine-Bis(3-phenylpropane) N,N′-Dioxide (7p)
Biology
From 2.98 g (0.02 mol) 3-phenylpropanal oxime. Greenish leaves (etha-
nol), mp 175 °C (dec.), yield 2.1 g (65%).– Anal. C20H24N2O2.– IR (KBr):
ν = 3101 cm–1; 1530 (C=N); 1147 (NO).– 1H-NMR/400 MHz (CDCl3): δ
(ppm) = 2.27 (tt, J = 7.1/ 7.1 Hz, 4H, 2 × Ph-CH2-CH2), 2.70 (t, J = 7.4 Hz,
4H, 2 × Ph-CH2-CH2), 3.90 (t, J = 7.0 Hz, 4H, 2 × N-CH2-CH2), 7.17–7.32
(m, 10H, 2 × Ph), 7.82 (s, 2H, N=CH-CH=N).– MS (70 eV): m/z (%) =324
(5) [M+], 307 (7) [M+–OH], 91 (100) [C7H7+], 69 (41), 41 (16).
Thrombosis experiments[11] and NO determination[17] were performed as
usual.
References
✩
Dedicated to Prof. Dr. F. Eiden on the occasion of his 75th birthday.
Ethanediylidenediamine-bis(4-methylphenylmethane) N,N′-Dioxide (7q)
[1] W. Chamulitrat, S. Jordan, R. P. Mason, K. Saito, R. G. Gutler, J. Biol.
Chem. 1993, 268, 11520–11527.
From 2.7 g (0.02 mol) 4-methylbenzaldoxime. Colorless crystals (etha-
nol), mp 195 °C (dec.), yield 2.1 g ( 72%).– Anal. C18H20N2O2.– IR (KBr):
ν = 3102 cm–1; 1529 (C=N); 1151 (NO).– 1H-NMR/400 MHz (CF3COOD):
δ (ppm) = 2.39 (s, 6H, 2 × CH3), 5.24 (s, 4H, 2 × N-CH2-), 7.28–7.32 (m,
8H, 2 × Ph-2H-3H-5H-6H), 8.29 (s, 2H, N=CH-CH=N).– MS (70 eV): m/z
(%) =296 (5) [M+], 105 (100) [C7H7–CH3+], 77 (8) [C6H5+].
[2] E. A. Konorev, J. E. Baker, J. Joseph, B. Kalyanaraman, Free Radical
Biol. Med. 1993, 14, 127–137.
[3] K. Rehse, U. Müller, Arch. Pharm. (Weinheim) 1995, 328, 765–769.
[4] K. Rehse, M. Herpel, Arch. Pharm. Pharm. Med. Chem. 1998, 331,
Ethanediylidenediamine-bis(4-methoxyphenylmethane) N,N′-Dioxide (7r)
104–110.
From 3.0 g (0.02 mol) 4-methoxybenzaldoxime. Yellowish-greenish crys-
tals (ethanol), mp 209 °C (dec.), yield 2.2 g (68%).– Anal. C18H20N2O4.– IR
(KBr): ν = 3101 cm–1; 1528 (C=N); 1147 (NO).– 1H-NMR/400 MHz
(CF3COOD): δ (ppm) = 4.01 (s, 6H, 2 × CH3), 5.26 (s, 4H, 2 × N-CH2-),
7.12 (“d”, J = 8.5 Hz, 4H, Ph-3H-5H), 7.45 (“d”, J = 8.5 Hz, 4H, Ph-2H-6H),
8.37 (s, 2H, N=CH-CH=N).– MS (70 eV): m/z (%) =328 (2) [M+], 121 (100)
[C7H7–OCH3+], 78 (8).
[5] M. Kämpfe, PhD thesis, FU Berlin 1983.
[6] E. Lüdtke, PhD thesis, FU Berlin 1992.
[7] L. Neelakantan, W. H. Hartung, J. Org. Chem. 1958, 23, 964–967.
[8] H. Feuer, B. F. Vincent, R. S. Bartlett, J. Org. Chem. 1965, 30,
2877–2880.
[9] V. Hach, Synthesis 1974, 340.
Ethanediylidenediamine-bis(4-chlorophenylmethane) N,N′-Dioxide (7s)
[10] G. Zinner, O. Hantelmann, U. Dybowski, Chem.-Ztg 1973, 97, 205.
From 3.1 g (0.02 mol) 4-chlorobenzaldoxime. Yellowish-greenish crystals
(ethanol), mp 155 °C (dec.), yield 1.4 g (41%).– Anal. C16H14N2O2Cl2.– IR
(KBr): ν = 3100 cm–1; 1528 (C=N); 1151 (NO); 1097 (NO).– 1H-NMR/400
MHz (CF3COOD): δ (ppm) = 5.27 (s, 4H, 2 × N-CH2-), 7.39–7.46 (m, 8H,
2 × Ph-2H-3H-5H-6H), 8.46 (s, 2H, N=CH-CH=N).– MS (70 eV): m/z (%)
=336 (4) [M+], 140 (26), 139 (39), 125 (100) [C7H7Cl+], 89 (25), 75 (16), 63
(12).
[11] K. Rehse, A. Kesselhut, V. Schein, M. Kämpfe, B. Rose, E. Unsöld,
Arch. Pharm. (Weinheim) 1991, 324, 301–305.
[12] K. Rehse, T. Ciborski, Arch. Pharm. (Weinheim) 1995, 328, 71–75.
[13] K. Rehse, S. Bade, Arch. Pharm. Pharm. Med. Chem. 1996, 329,
535–540.
[14] M. P. Cava, R. L. Litle, D. R. Napier, J. Amer. Chem. Soc. 1958, 80,
Ethanediylidenediamine-bis(4-trifluoromethylphenylmethane) N,N′-Diox-
ide (7t)
2257–2260.
[15] K. Satyanarayana, K. Rehse, Arch. Pharm. (Weinheim) 1998, 331,
From 1.7 g (0.02 mol) 4-trifluoromethylbenzaldoxime. Greenish crystals
(chloroform), mp 187 °C (dec.), yield 0.9 g (45%).– Anal. C18H14F6N2O2.–
IR (KBr): ν = 3102 cm–1; 1530 (C=N); 1335 (C-F); 1150 (NO).– 1H-
NMR/400 MHz (CF3COOD): δ (ppm) = 5.36 (s, 4H, 2 × N-CH2-), 7.62 (“d”,
J = 6.7 Hz, 4H, Ph-2H-6H), 7.75 (“d”, J = 6.7 Hz, 4H, Ph-3H-5H), 8.59 (s,
2H, N=CH-CH=N).– MS (70 eV): m/z (%) = 404 (8) [M+], 213 (19), 159
(100) [C7H7–CF3+], 109 (19).
207–210.
[16] A. Kesselhut, H. Ebel, F.v. Bruchhausen, K. Rehse, Arch. Pharm.
(Weinheim) 1995, 328, 21–27.
[17] H. J. Duchstein, S. Riederer, Arch. Pharm. (Weinheim) 1995, 328,
317–324.
[18] K. Rehse, S. Bade, A. Harsdorf, B. Clement, Arch. Pharm. Pharm. Med.
Chem. 1997, 330, 392–398.
Ethanediylidenediamine-bis(4-nitrophenylmethane) N,N′-Dioxide (7u)
From 1.6 g (0.02 mol) 4-nitrobenzaldoxime. Brownish powder, mp 148 °C
[19] U. Krüger, G. Zinner, Arch. Pharm. (Weinheim) 1978, 311, 39–47.
(dec.), yield 1.0 g (56%).– Anal. C16H14N4O6.– IR (KBr): ν = 3097 cm–1
;
1522 (C=N); 1156 (NO).– 1H-NMR/400 MHz ([D6] DMSO): δ (ppm) = 5.27
(s, 4H, 2 × N-CH2-), 7.70 (“d”, J = 9.0 Hz, 4H, Ph-2H-6H), 8.23–8.25 (m,
6H, 2 × Ph-3H-5H and 1 × N=CH-CH=N).– MS (70 eV): m/z (%) =358 (5)
[M+], 150 (52), 144 (24), 136 (34) [C7H7–NO2+], 91 (16), 89 (46), 78 (53),
77 (38), 51 (42), 50 (32), 43 (20), 41 (17), 39 (26), 32 (14), 30 (100) [NO+].
[20] E. Bamberger, Vierteljahrsschr. Naturforsch. Ges. Zuerich 1896, 2,
178.
[21] J. Thesing, W. Sirrenberg, Ber. Dtsch. Chem. Ges. 1958, 91, 1980.
Received: December 22, 1999 [FP445]
Arch. Pharm. Pharm. Med. Chem. 333, 130–134 (2000)