Synthesis of heterocyclic geminal nitro azides

Article abstract of DOI:10.1007/s11172-009-0323-9

The oxidative azidation reactions of C-nitro-substituted saturated heterocyclic compounds, viz., the nitro derivatives of oxetane, azetidine, 1,3-dioxane, tetrahydro-1,3-oxazine, and hexahydropyrimidine, were investigated. A novel representatives of the geminal nitro azides were prepared and their physicochemical properties were studied. The process of the formation of the geminal dinitro compounds upon oxidative azidation was analyzed.

Full text of DOI:10.1007/s11172-009-0323-9

Russian Chemical Bulletin, International Edition, Vol. 58, No. 11, pp. 2311—2317, November, 2009
2311
Synthesis of heterocyclic geminal nitro azides*
D. V. Katorov, G. F. Rudakov, and V. F. Zhilin
D. Mendeleyev University of Chemical Technology of Russia,
9 Miusskaya pl., 125047 Moscow, Russian Federation.
Eꢀmail: KatorovDV@mail.ru
The oxidative azidation reactions of Сꢀnitroꢀsubstituted saturated heterocyclic compounds,
viz., the nitro derivatives of oxetane, azetidine, 1,3ꢀdioxane, tetrahydroꢀ1,3ꢀoxazine, and
hexahydropyrimidine, were investigated. A novel representatives of the geminal nitro azides
were prepared and their physicochemical properties were studied. The process of the formation
of the geminal dinitro compounds upon oxidative azidation was analyzed.
Key words: oxidative azidation, nitration, geminal nitro azides.
To reveal the influence of the structure of the heteroꢀ
cycle, the nature of the heteroatom and subsituents, we
studied in the present work the oxidative azidation reacꢀ
tion by the example of nitro derivatives of 1,3ꢀdioxane
1a—g, 1,3ꢀtetrahydrooxazine 1h,i, hexahydropyrimidine
1j,k (Scheme 1, Table 1), oxetane 4a, and azetidine 4b
(Scheme 2, Table 2).
Organic azides occupy a prominent place in the chemꢀ
istry of energetic compounds. Thanks to the high heat
content, they are important as active plasiticizers and
highly energetic additives and also can serve as intermediꢀ
ates for the synthesis of various heterocyclic systems.1—3
At present, geminal azido nitro compounds are one
of the less studied class of azido compounds. The list of
the described αꢀnitro azides is limited and does not proꢀ
vide insight into the possibility of their synthesis in the
series of heterocycles.4—9
Table 1. The yields and physicochemical parameters of sixꢀmemꢀ
bered heterocyclic geminal nitro azides 2a—k
The main method for the preparation of αꢀnitro azides
consists of oxidative coupling of the azide anion with
nitroalkane salts. The reaction is performed in an alkaline
medium in the excess of azide under the conditions of
electrochemical4,6,9 and chemical oxidation.5,7,8 In the
latter case, ammonium persulfate or potassium ferriꢀ
cyanide are most widely used as oxidants.
Both primary and secondary (linear and cyclic) nitroꢀ
alkanes undergo azidation. Depending on the structure of
the hydrocarbon group and the method of oxidation, the
yield of nitro azide varies over a wide range (16—89%).
2
X
Y
R1
R2
R3
R4 Yield M.p./°С
20
(%)
(nD
)
a
b
c
d
e
f
g
h
i
O
O
O
O
O
O
O
O
O
N
N
O
O
O
O
O
O
O
N
N
—
—
—
—
—
—
—
—
—
H
H
Me
Me
H
H
Me
Me
Et
Ph
—
—
—
—
—
—
—
64
66
71
70
35—36
25—26
39—40.5
(1.4699)
81 101.5—103
62
60
H
mꢀNO2C6H4
80.5—83
25—30
33—35
—(CH2)4—
H
H
H
H
H
But 58
H
H
H
CH2Ph 73
72.5—75
j
k
N Pri
N But
Pri 71 12 (1.4870)
* Dedicated to the memory of Corresponding Member of the
Academy of Sciences of the USSR S. S. Novikov on the occaꢀ
sion of his 100th anniversary.
But 53
57—58
Scheme 1
3a: R1X = R4Y = O, R2 = R3 = Me; 3b: R1X = O, R4Y = ButN, R2 = R3 = H; 3c: R1X = R4X = NBut, R2 = R3 = H
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2240—2246, November, 2009.
1066ꢀ5285/09/5811ꢀ2311 © 2009 Springer Science+Business Media, Inc.

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Russ.Chem.Bull., Int.Ed., Vol. 58, No. 11, November, 2009
Katorov et al.
Scheme 2
Y (%)
60
2h
3b
40
20
0
20
40
60
80
100 120 140 t/min
Fig. 1. Dependence of the yields (Y) of compounds 2h and 3b
on the reaction time upon azidation (nitration) of 3ꢀtertꢀbutylꢀ
5ꢀhydroxymethylꢀ5ꢀnitrotetrahydroꢀ1,3ꢀoxazine (1h) (see
Scheme 3).
Table 2. The yields and physicochemical parameters of
fourꢀmembered heterocyclic geminal nitro azides 5a,b
Scheme 3
5
X
R5
R6
Yield
(%)
M.p./°С
20
(nD
)
a
b
O
N
H
—
But
26*
60
—
CH2OH
3—5
(1.4360)
1
* According to the H NMR spectral data.
Nu = N3 (2h), NO2 (3b)
Except for oxetane, the salts of the nitroꢀsubstituted
heterocycles were prepared by the Henry retroreaction
directly from hydroxymethyl derivatives 1 (see Schemes 1
and 2). Potassium ferricyanide was used as the oxidant.
It was shown that, regardless of the structure of the
heterocyle, the main reaction product is gemꢀazido nitro
compound 2a—k, 5a,b (see Scheme 1, 2, Tables 1, 2).
The nature of the substituent in position 2 of 1,3ꢀdioxane,
as well as the passage to nitrogen heterocycles have no
noticeable effect on the reaction pathway.
1ꢀtertꢀButylꢀ3ꢀhydroxymethylꢀ3ꢀnitroazetidine (4b),
as in the case of the sixꢀmembered heterocyles, affords
3ꢀazidoꢀ1ꢀtertꢀbutylꢀ3ꢀnitroazetidine (5b) in a good
yield (see Scheme 2, Table 2). The decrease in the yield
was observed only in the case of 3ꢀnitrooxetane (4a). This
fact can be explained by the typical behavior of
3ꢀnitrooxetane in the oxidative coupling reactions. For
example, upon nitration under the same conditions,10 the
yield of 3,3ꢀdinirooxetane was only 22%.
Scheme 4
Nu = N3 (5b), NO2 (6b)
Y (%)
6b
80
5b
60
40
20
0
100 200 300 400 500 600 700 t/min
We observed the difference in the rates of azidation of
the fourꢀ and sixꢀmembered rings (Figs 1, 2, Schemes 3,
4). Azidation of oxazine 1h proceeds considerably faster
than that of azetidine 4b. The similar effect was observed
by us in studies of oxidative nitration of compounds
1h and 4b. It should be noted that nitration proceeds
2—4ꢀfold faster than azidation.
Fig. 2. Dependence of the yields (Y) of compounds 5b and 6b
on the reaction time upon azidation (nitration) of 1ꢀtertꢀbutylꢀ
3ꢀhydroxymethylꢀ3ꢀnitroazetidine (4b) (see Scheme 4).
derivatives 3 and 6 (see Schemes 1, 2). Their content
was determined by 1H NMR spectroscopy.
In contrast to 2ꢀazidoꢀ2ꢀnitropropane, the heterocyꢀ
clic azido nitro compounds do not undergo subsequent
nucleophilic subsitution reaction to form the gemꢀdiazido
derivative.5 The major byꢀproducts are gemꢀdinitro
The formation of the gemꢀdinitro derivatives upon
oxidative azidation also occured in the case of an analoꢀ
gous coupling reaction of nitroalkanes5,8 with the nitrite
anion. The nitrite anion can be formed upon decay of the

Synthesis of heterocyclic geminal nitro azides
Russ.Chem.Bull., Int.Ed., Vol. 58, No. 11, November, 2009 2313
Scheme 5
radical anions of the azido nitro compounds5 (Scheme 5)
or upon oxidation of the nitro compounds11 (Scheme 6).
The former pathway implies the formation of the gemꢀ
diazido compounds that are not found among the azidꢀ
ation reaction products. The addition of nitrite at the
different reaction steps leads to the proportional increase
in the yield of the gemꢀdinitro derivative12 in contrast
to 2ꢀnitropropane, for which the former pathway of the
formation of the nitrite anion is typical.5
yield of gemꢀdinitro product 6b does not change upon
increase in the reaction time (Table 3). It is seen from the
kinetic curves (see Figs 1, 2) that, in spite of the great
excess of the oxidant and sodium azide, nitro azide does
not disappear from the reaction mixture. Consequently, the
gemꢀdinitro compound is not produced from nitro azide.
Oxidation of the starting nitro compounds 1c and 4b
under the conditions similar to those of azidation affords
gemꢀdinitro compounds 3a and 6b in yields of 8 and 15%,
respectively, which suggests the formation of the nitrite
anion by the latter pathway. Generation of the radicals
of nitro compounds contemplates that the dimerization
reaction proceeds and results in the vicinal dinitro comꢀ
pounds. The absence of the dimerization products is
explained by the strong basicity of the reaction medium,
wherein the vicinal dinitro compounds practically do
not form.11
The analysis of the azidation products of 1ꢀtertꢀbutylꢀ
3ꢀhydroxymethylꢀ3ꢀnitroazetidine (4b) showed that the
Scheme 6
The structure of the heterocycle have an effect on the
yield of the byꢀproducts. In the case of the more strained
Table 3. The yields of nitro azides 2c,h, 5a,b and geminal dinitro
compounds 3a,b, 6a,b upon oxidative azidation
Starting
t/h
mNaOH
Yield (%)
compound
/equiv.
Nitro azide gemꢀDinitro
compound
1c
1h
4a
4b
24
4.5
4
4.5
5
3
1.5
5
5
69 (2c)
55 (2h)
26 (5a)
49 (5b)
50 (5b)
2 (3a)
3 (3b)
12 (6a)
11 (6b)
10 (6b)
24

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Russ.Chem.Bull., Int.Ed., Vol. 58, No. 11, November, 2009
Katorov et al.
fourꢀmembered rings, the content of the gemꢀdinitro comꢀ
pounds is significantly higher than in the case of the sixꢀ
membered rings (see Table 3). This fact can be explained
by the strain in the fourꢀmembered rings.
The nitro azides obtained are insufficiently stable
under the conditions of acid nitration compared to the
gemꢀdinitro analogs (Scheme 7, Table 4). The yields upon
substitutive nitration of the Nꢀtertꢀbutylꢀsubstituted nitro
azides 2h,k, 5b are considerably lower than in the case of
gemꢀdinitro analogs 3b,c, 6b. The best results were
achieved when the system N2O5—MeCN was applied.
Nitro azides, except for 2k, and dinitro compounds are
nitrated in this system in almost equal yields.
nitramines. The addition of NH4Cl, which was successꢀ
fully used in the nitration of the gemꢀdinitro analogs,13
have no positive effect on the outcome of the reaction.
Nitration of the derivatives of 1,3ꢀdioxane affords the
product whose IR spectrum contains the bands characterꢀ
istic of both the nitrate and azido groups. However, we
did not succeed in isolating it in a pure state because of its
low chemical stability.
Studies of the obtained compounds by thermal graviꢀ
metry (TGA) and differential scanning calorimetry (DSC)
showed that nitro azides decomposed at 150—160 °С. It
was found that the structure of the heterocycle influences
the stability of the αꢀnitro azide. Compounds 2h,j,k and
5b containing the strong electronꢀdonating substituents
(tertꢀbutyl, isopropyl) are stable only at low temperatures
(–20 °С) and decomposed at room temperature within
1 month to form a complex mixture of products, the IR
spectrum of which does not contain the bands that are
typical of antisymmetric stretching vibrations of the —N3
and —NO2 groups. The replacement of the Nꢀalkyl group
by the nitro group results in the stabilization of the strucꢀ
ture. For example, compounds 7, 9, and 11 do not show
the signs of lightꢀinduced decomposition at room
temperature. The azido nitro derivatives of 1,3ꢀdioxane,
regardless of the structure and nature of the substituent,
are stable at room temperature.
Scheme 7
The αꢀnitro azides obtained are colorless solids and
compound 5b is a paleꢀyellow liquid. According to the
1
data from Н NMR spectroscopy, compound 2d was
obtained as a 1 : 1 mixture of two isomers with the axial
(2dax) and equatorial (2deq) positions of the azido group.
Nu = N3 (2, 5, 7, 9, 11), NO2 (3, 6, 8, 10, 12)
Nitration in media with higher acidity and the inꢀ
crease in temperature lead to the increase in the degree of
destructive processes and the decrease in the yield of
The structures of the obtained compounds were estabꢀ
1
lished by IR spectroscopy, as well as by Н and 13С specꢀ
Table 4. The yields (%) of Nꢀnitro compounds 7—12 depending on the nature of the nitration mixture (see Scheme 7)
+
Starting
Product
Nitration system (NO2
)
compound
HNO3 H2SO4—HNO3 Ac2O—HNO3* NH4NO3—Ac2O** NH4NO3—(CF3O)2O N2O5—MeCN
2h
3b
2k
3c
5b
6b
7
8
9
10
11
12
0
23
—
—
—
—
—
—
0
81
—
—
16
37
—
44
50
61
0
45
—
—
21
82
23
60
—
22
—
—
60
66
11
54
61
64
* A 1 : 1 ratio.
** T = 70 °С.

Synthesis of heterocyclic geminal nitro azides
Russ.Chem.Bull., Int.Ed., Vol. 58, No. 11, November, 2009 2315
Table 5. Spectral data for the nitro azides obtained
Comꢀ
pound
IR spectrum, ν/cm–1
13C NMR spectrum (CDCl3)
N3
NO2 (as)
NO2 (s)
Frequency/MHz
C(NO2)N3, δ
2a
2b
2c
2d*
2e
2f
2g
2h
2i
2j**
2k
4a***
4b
7
9**
11
2130
2135
2142
2125
2128
2134
2126
2124
2145
2119
2126
2140
2128
1560
1561
1558
1319
1340
1337
1337
1329
1331
1339
1345
1325
1341
1348
1336
1353
50
50
50
50
50
75
50
50
50
75
50
—
92.6
92.7
94.3
1561
93.9, 94.37
92.6
1566, 1552
1559
92.5
93.5
95.0
93.9
97.1
97.7
—
92.1
1559
1560
1556
1555
1553
1590—1558
1558
1561
1566
1576, 1561
50
50
75
75
2150, 2132
2140
1326, 1287
1343, 1293
1352, 1342
93.7
94.9
89.0
2135
* An isomeric mixture.
** The spectrum was recorded in DMSOꢀd6.
*** In a mixture with 3,3ꢀdinitrooxetane.
(400 MHz) instruments in CDCl3 and DMSOꢀd6. The IR spectra
were recorded on a Thermo Nicolet 360 FT IR spectrometer in
KBr pellets (7 mm in diameter). The melting points were
troscopy. In the IR spectra, the absorption bands are reꢀ
corded in the region of the absorption of the azido group
(2119—2142 cm–1), the symmetrical (1325—1360 cm–1)
and antisymmetrical (1554—1566 cm–1) vibrations of
the nitro group (Table 5). In the 13С NMR spectrum, the
resonance signals for the carbon atom bearing the nitro
and the azido groups are in the region of δ 89—98 (see
Table 5).
The analysis of the IR spectra suggests the presence of
the strong interaction between the azido group and the
nitroamine fragment (see Table 5). The replacement of
the tertꢀbutyl by the nitro group results in the appreciable
shift of the antisymmetrical vibration band of —N3 to the
highꢀfrequency region, which is evidence of appearance
of higher rigidity in the structure of the azido group.
Introduction of the azido group also results in the shift of
the antisymmetrical vibration band of NNO2 to the highꢀ
frequency region, which can be explained by the formaꢀ
tion of more planar configuration of the nitramine unit
and, as a consequence, by certain decrease in the N—N
bond length, which determines the higher stability of
compounds 7, 9, and 11.
measured on a Boetius heating table at the heating rate 2 °С min–1
.
DSC and TGA studies of the thermal stability were performed
on a Mettler Toledo DSC 822c instrument. The heating rate was
10 °С min–1 in the temperature range 20—250 °С. The course of
the reaction was monitored by TLC using Sorbfil PTLCꢀAFꢀАꢀUV
plates. The compounds obtained were purified by preparative
chromatography on silica gel (Durasil H, 60–100 μ).
Compound 1a was synthesized by the cyclization reaction of
dimethoxymethane and nitroisobutylglycerol.14 Compounds
1b—g were prepared by the cyclization reaction of nitroꢀ
isobutylglycerol with the corresponding ketones in the presence
of BF3•Et2O or pꢀtoluenesulfonic acid.15 Compounds 1h—k
were synthesized by the Mannich reaction from nitroisoꢀ
butylglycerol, formaldehyde, and the corresponding amine.16
Compounds 4a and 4b were synthesized according to the
previously described procedures.10,17
Oxidative coupling of nitro compounds (general procedure).
The starting nitro compound 1 or 4 (1 equiv.) was added with
stirring at ∼20 °C to a 20% aqueous solution of NaOH (5 equiv.)
and the reaction mixture was kept for 10—15 min. To the
resulting mixture, a saturated aqueous solution of NaN3 (NaNO2)
(5 equiv.) was added and the mixture was poured with stirring
into a saturated aqueous solution of K3Fe(CN)6 (5 equiv.). The
reaction mixture was stirred for 2.5—4 h at ~20 °C and extracted
with ethyl acetate. The extract was washed with brine, dried with
magnesium sulfate, and concentrated on a rotary evaporator. If
necessary, the obtained product was purified by preparative
chromatography. (СHCl3—CCl4, 1 : 1 (v/v)).
Experimental
Attention! The azido nitro compounds and byꢀproducts that
can be formed in the preparation of the azido nitro compounds are
toxic and explosive. Observe appropriate precautions during their
handling!
The 1H and 13С spectra were recorded on Bruker ACꢀ200
(200 MHz), Bruker AMꢀ300 (300 MHz) and Bruker AMXꢀ400
5ꢀAzidoꢀ5ꢀnitroꢀ1,3ꢀdioxane (2a). IR, ν/cm–1: 3006, 2947,
2875 (CH); 2130 (N3); 1560, 1319 (NO2). 1H NMR (400 MHz,
CDCl3), δ: 4.01 (d, 2 H, O—CH2—C, J = 11.9 Hz); 4.52 (d, 2 H,

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Katorov et al.
O—CH2—C, J = 11.9 Hz); 4.85 (d, 1 H, O—CH2—O, J = 6.2 Hz);
4.90 (d, 1 H, O—CH2—O, J = 6.2 Hz). 13C NMR (50 MHz,
CDCl3), δ: 68.6 (O—CH2—C); 92.6 (C(NO2)N3); 93.6
(O—CH2—O). Found (%): C, 27.63; H, 3.49; N, 32.15.
C4H6N4O4. Calculated (%): C, 27.59; H, 3.47; N, 32.18.
5ꢀAzidoꢀ3ꢀtertꢀbutylꢀ5ꢀnitrotetrahydroꢀ1,3ꢀoxazine (2h). IR,
ν/cm–1: 2975, 2875, 2837 (CH); 2124 (N3); 1560, 1345 (NO2).
1H NMR (200 MHz, CDCl3), δ: 1.10 (s, 9 H, Me); 3.14 (d,
1 H, C—CH2—N, J = 12.1 Hz); 3.58 (d, 1 H, C—CH2—N,
J = 12.5 Hz); 3.73 (dd, 1 H, O—CH2—C, J = 12.1 Hz,
J = 1.0 Hz); 4.29 (m, 1 H, O—CH2—C, 2 H, N—CH2—O).
13C NMR (50 MHz, CDCl3), δ: 26.6 (Me); 50.7 (C—CH2—N);
53.3 (N—CMe); 69.1 (O—CH2—C); 81.0 (O—CH2—N);
95.0 (C(NO2)N3). Found (%): C, 41.85; H, 6.63; N, 30.48.
C8H15N5O3. Calculated (%): C, 41.92; H, 6.60; N, 30.55.
5ꢀAzidoꢀ2ꢀmethylꢀ5ꢀnitroꢀ1,3ꢀdioxane (2b). IR, ν/cm–1
:
2873 (CH); 2135 (N3); 1561, 1340 (NO2). 1H NMR (400 MHz,
CDCl3), δ: 1.45 (d, 3 H, Me, J = 4.9 Hz); 4.27 (s, 4 H, CH2);
4.81 (q, 1 H, CH, J = 5.0 Hz). 13C NMR (50 MHz, CDCl3),
δ: 19.9 (Me); 68.9 (CH2); 92.7 (C(NO2)N3); 100.2 (CH).
Found (%): C, 31.90; H, 4.21; N, 29.65. C5H8N4O4. Calculꢀ
ated (%): C, 31.92; H, 4.29; N, 29.78.
5ꢀAzidoꢀ3ꢀbenzylꢀ5ꢀnitrotetrahydroꢀ1,3ꢀoxazine
(2i).
IR, ν/cm–1: 3087, 3061, 3036 (C—H arom.); 2934, 2866 (CH);
2145 (N3); 1556, 1325 (NO2). 1H NMR (200 MHz, CDCl3),
δ: 3.27 (d, 1 H, C—CH2—N, J = 13.4 Hz); 3.76 (d, 1 H,
C—CH2—N, J = 13.4 Hz); 4.06 (m, 1 H, C—CH2—O, 2 H,
Ph—CH2—N); 4.34 (m, 1 H C—CH2—O, 2 H, N—CH2—O);
7.35 (s, 5 H, Ph). 13С NMR (50 MHz, CDCl3), δ: 54.0
(Car—CH2—N); 56.1 (N—CH2—C); 69.6 (C—CH2—O); 83.2
(O—CH2—N); 93.9 (C(NO2)N3); 127.5 (Cp arom.); 128.4
(Cm arom.); 128.6 (Co arom.); 137.0 (CH2—Car). Found (%):
C, 50.15; H, 4.99; N, 26.50. C11H13N5O3. Calculated (%):
C, 50.19; H, 4.98; N, 26.60.
5ꢀAzidoꢀ2,2ꢀdimethylꢀ5ꢀnitroꢀ1,3ꢀdioxane (2c). IR, ν/cm–1
:
3003, 2984, 2947 (CH); 2142 (N3); 1558, 1337 (NO2). 1H NMR
(200 MHz, CDCl3), δ: 1.45 (s, 3 H, Me); 1.46 (s, 3 H, Me); 4.00
(d, 2 H, CH2, J = 12.8 Hz); 4.48 (d, 2 H, CH2, J = 12.5 Hz).
13C NMR (50 MHz, CDCl3), δ: 22.6 (Me); 23.2 (Me); 62.8
(CH2); 94.3 (C(NO2)N3); 99.9 (C). Found (%): C, 35.69;
H, 5.03; N, 27.68. C6H10N4O4. Calculated (%): C, 35.65;
H, 4.99; N, 27.71.
5ꢀAzidoꢀ2ꢀethylꢀ2ꢀmethylꢀ5ꢀnitroꢀ1,3ꢀdioxane (2d), a 1 : 1
mixture of isomers (1H NMR data). IR, ν/cm–1: 2983, 2945
(CH); 2125 (N3); 1561, 1337 (NO2). 1H NMR (400 MHz,
CDCl3), δ: 0.91, 0.96 (both t, total 3 H, CH2—CH3, J = 7.5 Hz);
1.42 (s, 3 H, Me); 1.72—1.81 (m, 2 H, CH2—CH3); 4.00, 4.02
(both d, total 2 H, CH2, J = 12.8); 4.48, 4.51 (both d, total
2 H, CH2, J = 12.8). 13C NMR (50 MHz, CDCl3), δ: 7.4, 7.6
(CH2—CH3); 18.9, 19.3 (Me); 29.3, 29.9 (CH2Me); 62.4,
62.6 (CH2); 93.9, 94.37 (C(NO2)N3); 101.5 (C). Found (%):
C, 38.92; H, 5.63; N, 25.85. C7H12N4O4. Calculated (%):
C, 38.89; H, 5.59; N, 25.92.
5ꢀAzidoꢀ1,3ꢀdiisopropylꢀ5ꢀnitrohexahydropyrimidine (2j).
IR, ν/cm–1: 2968, 2932 (CH); 2119 (N3); 1555, 1341 (NO2).
1H NMR (300 MHz, DMSOꢀd6), δ: 1.04 (d, 12 H, Me,
J = 6.40 Hz); 2.92 (m, 2 H, CHMe); 2.97 (d, 2 H, N—CH2—C,
J = 11.4 Hz); 3.23 (d, 2 H, N—CH2—C, J = 11.9 Hz); 3.31
(d, 1 H, N—CH2—N, J = 9.1 Hz); 3.46 (d, 1 H, N—CH2—N,
J = 9.1 Hz). 13C NMR (75 MHz, DMSOꢀd6), δ: 18.5 (Me);
51.3 (N—CH2—C); 51.7 (CH); 67.9 (N—CH2—N); 97.1
(C(NO2)N3). Found (%): C, 46.79; H, 7.90; N, 32.65.
C10H20N6O2. Calculated (%): C, 46.86; H, 7.87; N, 32.79.
5ꢀAzidoꢀ1,3ꢀdiꢀtertꢀbutylꢀ5ꢀnitrohexahydropyrimidine (2k).
IR, ν/cm–1: 2971 (Me); 2126 (N3); 1553, 1348 (NO2). 1H NMR
(200 MHz, CDCl3), δ: 1.09 (s, 18 H, Me); 2.99 (d, 2 H,
N—CH2—C, J = 11.8 Hz); 3.19 (d, 2 H, N—CH2—C,
J = 11.8 Hz); 3.26 (d, 1 H, N—CH2—N, J = 9.1 Hz); 3.62
(d, 1 H, N—CH2—N, J = 9.1 Hz). 13C NMR (50 MHz, CDCl3),
δ: 26.1 (Me); 51.1 (N—CH2—C); 53.8 (CHMe); 63.6
(N—CH2—N); 97.7 (C(NO2)N3). Found (%): C, 50.71;
H, 8.58; N, 29.53. C12H24N6O2. Calculated (%): C, 50.69;
H, 8.51; N, 29.55.
5ꢀAzidoꢀ5ꢀnitroꢀ2ꢀphenylꢀ1,3ꢀdioxane (2e). IR, ν/cm–1
:
3096, 3064, 3043 (CH arom.); 2944, 2885, 2877 (CH); 2128,
2116 (N3); 1566, 1552, 1329 (NO2). 1H NMR (400 MHz,
CDCl3), δ: 4.44 (d, 2 H, CH2, J = 11.5 Hz); 4.51 (d, 2 H, CH2,
J = 11.5 Hz); 5.64 (s, 1 H, CH); 7.44 (m, 3 H, Ph); 7.53 (m,
2 H, Ph). 13C NMR (50 MHz, CDCl3), δ: 69.1 (CH2);
92.6 (C(NO2)N3); 101.8 (C—Сar); 126.0 (Сo arom.); 128.4
(Сm arom.); 129.6 (Сp arom.); 135.6 (Car—CO). Found (%):
C, 48.08; H, 3.95; N, 22.28. C10H10N4O4. Calculated (%):
C, 48.00; H, 4.03; N, 22.39.
5ꢀAzidoꢀ5ꢀnitroꢀ2ꢀ(3ꢀnitrophenyl)ꢀ1,3ꢀdioxane (2f). IR, ν/cm–1
:
3102, 3087, 3051 (CH arom.); 2988, 2962 (CH); 2134
(N3); 1534, 1352 (s, NO2 arom.); 1559, 1331 (NO2). H NMR
3ꢀAzidoꢀ3ꢀnitrooxetane (5a) was prepared as a mixture with
3,3ꢀdinitrooxetane (6a)10. IR, ν/cm–1: 2957, 2888 (CH); 2140
(N3); 1590—1558, 1336 (NO2). 1H NMR (300 MHz, CDCl3),
δ: 4.77 (d, 2 H, J = 8.1 Hz); 5.17 (d, 2 H, J = 8.1 Hz); 5.29* (s, 6a).
3ꢀAzidoꢀ1ꢀtertꢀbutylꢀ3ꢀnitroazetidine (5b). IR, ν/cm–1: 2968
(CH); 2128 (N3); 1558, 1353 (NO2). 1H NMR (200 MHz,
CDCl3), δ: 0.98 (s, 9 H, Me); 3.47 (dd, 2 H, CH2, J = 8.3 Hz,
J = 1.7 Hz); 3.91 (dd, 2 H, CH2, J = 8.3 Hz, J = 1.7 Hz).
13С NMR (50 MHz, CDCl3), δ: 23.8 (Me); 52.3 (N—CMe);55.4
(CH2); 92.1 (C(NO2)N3). Found (%): C, 42.11; H, 6.50; N, 35.06.
C7H13N5O2. Calculated (%): C, 42.20; H, 6.58; N, 35.16.
3ꢀtertꢀButylꢀ5,5ꢀdinitrotetrahydroꢀ1,3ꢀoxazine (3b).18,19
The yield was 51%, m.p. 83—85 °С. IR, ν/cm–1: 2985 (CH);
1572, 1366 (NO2). 1H NMR (300 MHz, CDCl3), δ: 1.11 (s,
9 H); 3.83 (s, 2 H); 4.37 (s, 2 H); 4.49 (s, 2 H).
1
(300 MHz, CDCl3), δ: 4.44 (d, 2 H, CH2, J = 11.7 Hz); 4.52
(d, 2 H, CH2, J = 11.7 Hz); 5.70 (s, 1 H, CH); 7.59 (t, 1 H, Ph,
J = 8.1 Hz); 7.83 (d, 1 H, Ph, J = 7.3 Hz); 8.25 (d, 1 H, Ph,
J = 8.1 Hz); 8.36 (s, 1 H, Ph). 13C NMR (75 MHz, CDCl3),
δ: 69.2 (CH2); 92.5 (C(NO2)N3); 100.1 (C—Сar); 121.5
(Car—CH—CNO2); 124.4 (CH—CH—CNO2); 129.5
(CH—CH—CH); 132.2 (Car—CH—CH); 137.5 (Car—CO);
148.1 (CarNO2)). Found (%): C, 40.58; H, 3.12; N, 23.68.
C10H9N5O6. Calculated (%): C, 40.69; H, 3.07; N, 23.72.
8ꢀAzidoꢀ8ꢀnitroꢀ6,10ꢀdioxaspiro[4.5]decane (2g). IR, ν/cm–1
:
2974, 2945, 2878 (CH); 2126 (N3); 1559, 1339 (NO2). 1H NMR
(200 MHz, CDCl3), δ: 1.67 (s, 4 H, CH2CH2); 1.89 (s, 4 H,
CH2CH2); 3.98 (d, 2 H, C—CH2—O, J = 11.8 Hz); 4.46 (d,
2 H, C—CH2—O, J = 11.8 Hz). 13C NMR (50 MHz, CDCl3),
δ: 23.2 (CH2—CH2—CH2—CH2); 34.1 (C—CH2—CH2); 34.5
(C—CH2—CH2); 64.1 (C(NO2)—CH2—O); 93.5 (C(NO2)N3);
111.5 (O2—C—(CH2)2). Found (%): C, 42.11; H, 5.32; N, 24.53.
C8H12N4O4. Calculated (%): C, 42.10; H, 5.30; N, 24.55.
1,3ꢀDiꢀtertꢀbutylꢀ5,5ꢀdinitrohexahydropyrimidine (3c).13,19
The yield was 48%, m.p. 75—76 °С. IR, ν/cm–1: 2968 (CH);
1568, 1367 (NO2).
* Signal of 3,3ꢀdinitrooxetane.

Synthesis of heterocyclic geminal nitro azides
Russ.Chem.Bull., Int.Ed., Vol. 58, No. 11, November, 2009 2317
1ꢀtertꢀButylꢀ3,3ꢀdinitroazetidine (6b).17 The yield was 75%,
m.p. 20 °С. IR, ν/cm–1: 2969 (CH); 1574, 1369 (NO2). 1H NMR
(300 MHz, CDCl3), δ: 1.01 (s, 9 H, Me); 4.08 (s, 4 H, CH2).
Study of kinetics of oxidative coupling. During azidation
(nitration) of compounds 1h or 4b, aliquots of the reaction
mixtures were withdrawn at definite intervals, extracted with
ethyl acetate and the extract was concentrated. The residue was
weighted, analyzed by HPLC and the yield of product 2h or 5b
was determined. The chromatographic analysis was carried out
on a Milichromꢀ4 instrument using a Silasorb CN chromatoꢀ
graphic column, 2.0×120 mm, 5 μm. The rate of eluent feed
(acetonitrile—water (1 : 1)) was 200 L min–1. The retention
times were 3.15 min for 2h, 3.75 min for 3b, 3.25 min for 5b, and
4.35 min for 6b.
(N—NO2). 1H NMR (200 MHz, CDCl3), δ: 4.6 (dd, 2 H, CH2,
J = 11.4 Hz, J = 1.4 Hz); 5.0 (dd, 2 H, CH2, J = 11.4 Hz,
J = 1.4 Hz). 13C NMR (75 MHz, CDCl3), δ: 65.3 (CH2);
89.0 (C(NO2)N3). Found (%): C, 19.06; H, 2.12; N, 44.60.
C3H4N6O4. Calculated (%): C, 19.16; H, 2.14; N, 44.68.
3,5,5ꢀTrinitrotetrahydroꢀ1,3ꢀoxazine (8).19,20 IR, ν/cm–1
3078, 3020, 2968 (CH); 1581, 1560, 1307, 1288 (NO2).
1,3,5,5ꢀТетраnitrohexahydropyrimidine (10).19,20 IR, ν/cm–1
:
:
3088, 3066, 3036 (CH); 1577, 1316, 1296 (NO2). 1H NMR
(200 MHz, DMSOꢀd6), δ: 5.34 (s, 4 H); 6.11 (s, 2 H).
1,3,3ꢀTrinitroazetidine (12).17 IR, ν/cm–1: 3038, 3022,
2975 (CH); 1601—1591, 1539, 1338, 1280 (NO2). 1H NMR
(200 MHz, acetoneꢀd6), δ: 5.45 (s).
Oxidation of nitro compounds. The starting nitro compound
1c or 4b (1 equiv.) was added with stirring at room temperature
to a 20% aqueous solution of NaOH (5 equiv.) and kept for
10—15 min. Then the mixture was poured with stirring into a
saturated aqueous solution of K3Fe(CN)6 (5 equiv.). The reaction
mixture was stirred for 24 h at ~20 °C and extracted with ethyl
acetate. The extract was washed with brine, dried with magneꢀ
sium sulfate, and concentrated on a rotary evaporator. The
residue was analyzed by 1H NMR spectroscopy and the yield of
gemꢀdinitro compound 3a or 6b was determined.
References
1. S. Patai, The Chemistry of the Azido Group, Interscience
Publishers, London, 1971.
2. The Chemistry of Heterocyclic Compounds, Vol. 59. Synthetic
Applications of 1,3ꢀDipolar Cycloaddition Chemistry Toward
Heterocycles and Natural Products, Eds A. Padwa, W. H.
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23, 4513; (b) S. I. AlꢀKhalil, W. R. Bowman, J. Chem. Soc.,
Perkin Trans. 1, 1986, 555.
2,2ꢀDimethylꢀ5,5ꢀdinitroꢀ1,3ꢀdioxane (3a).19 1H NMR
(300 MHz, CDCl3), δ: 1.45 (s, 6 H, Me); 4.65 (s, 4 H, CH2).
1ꢀtertꢀButylꢀ3,3ꢀdinitroazetidine (6b).17 1H NMR (300 MHz,
CDCl3), δ: 1.01 (s, 9 H, Me); 4.08 (s, 4 H, CH2).
Nitration. To a cooled (0—5 °С) solution of the Nꢀtertꢀbutyl
substituted derivative (2h,k, 3b,c, 5b, 6b) in anhydrous acetoꢀ
nitrile, a solution of nitric anhydride (3 equiv. per But group)
was slowly added, the temperature being maintained not above
5 °С. After completion of dosing, the mixture was kept for 1 h
at 5 °С, then poured onto ice and extracted with ethyl acetate.
The extract was washed with water until the neutral pH has been
achieved, dried with Na2SO4, and concentrated in vacuo
on a rotaty evaporator. The obtained product was purified by
preparative chromatography, if necessary.
6. J. F. Weber, M. B. Frankel, Prop. Explos. Pyrotech., 1990,
15, 26.
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R. Bau, G. A. Olah, J. Org. Chem., 1997, 62, 1872.
8. I. V. Tselinskii, S. F. Mel´nikova, S. A. Fedotov, Izv. Akad.
Nauk, Ser. Khim., 2002, 1354 [Russ. Chem. Bull., Int. Ed.,
2002, 51, 1466].
9. Yu. N. Ogibin, A. I. Ilovayskii, V. M. Merkulova, G. I.
Nikishin, Izv. Akad. Nauk, Ser. Khim., 2004, 2452 [Russ.
Chem. Bull., Int. Ed., 2004, 53, 2558].
10. K. Baum, P. T. Berkowitz, V. Grakauskas, T. G. Archibald,
J. Org. Chem., 1983, 48, 2953.
11. G. A. Russel, J. Am. Chem. Soc., 1954, 76, 1595.
12. D. V. Katorov, G. F. Rudakov, A. V. Ladonin, V. F. Zhilin,
E. V. Veselova, N. A. Vyalova, Central Eur. J. Energ. Mater.,
2007, 4, 125.
13. M. D. Cliff, Heterocycles, 1998, 48, 657.
14. J.ꢀL. Gras, R. Nouguier, M. Mchich, Tetrahedron Lett.,
1987, 28, 6601.
15. G. B. Linden, M. H. Gold, J. Org. Chem., 1956, 21, 1175.
16. T. Urbanski, Synthesis, 1974, 613.
17. D. S. Watt, M. D. Cliff, Aeronautical and Maritime Research
Laboratory, DSTOꢀTRꢀ1000, 2000.
5ꢀAzidoꢀ3,5ꢀdinitrotetrahydroꢀ1,3ꢀoxazine (7). IR, ν/cm–1
:
2150, 2132 (N3); 1561 (br, NO2); 1326 (C—NO2); 1287
(N—NO2). 1H NMR (200 MHz, CDCl3), δ: 4.17 (dd, 1 H,
C—CH2—O, J = 12.1 Hz, J = 2.1 Hz); 4.28 (d, 1 H, C—CH2—O,
J = 12.1 Hz); 4.44 (d, 1 H, N—CH2—C, J = 15.3 Hz); 4.91 (d,
1 H, O—CH2—N, J = 12.1 Hz); 4.94 (dt, 1 H, N—CH2—C,
J = 15.5 Hz, J = 2.0 Hz); 5.86 (dd, 1 H, O—CH2—N,
J = 12.1 Hz, J = 1.7 Hz). 13C NMR (50 MHz, CDCl3), δ: 50.2
(N—CH2—C); 70.0 (C—CH2—O); 77.2 (O—CH2—N);
93.7 (C(NO2)N3). Found (%): C, 22.11; H, 2.74; N, 38.49.
C4H6N6O5. Calculated (%): C, 22.03; H, 2.77; N, 38.53.
5ꢀAzidoꢀ1,3,5ꢀtrinitrohexahydropyrimidine (9). IR, ν/cm–1
:
2140 (N3); 1566 (br, NO2); 1343 (C—NO2); 1293 (N—NO2).
1H NMR (400 MHz, CDCl3), δ: 4.28 (d, 2 H, N—CH2—C,
J = 15.0 Hz); 5.05 (d, 1 H, N—CH2—N, J = 15.0 Hz); 5.07
(d, 2 H, N—CH2—C, J = 15.0 Hz); 7.05 (d, 1 H, N—CH2—N,
J = 15.0). 13C NMR (75 MHz, DMSOꢀd6), δ: 50.6 (N—CH2—C);
59.5 (N—CH2—N); 94.9 (C(NO2)N3). Found (%): C, 18.28;
H, 2.27; N, 42.65. C4H6N8O6. Calculated (%): C, 18.33;
H, 2.31; N, 42.75.
18. H. Piotrowska, T. Urbanski, K. WejrochꢀMatacz, Bull. Acad.
Polon. Sci., Ser. Sci. Chim., 1971, 19, 359.
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20. D. A. Cichra, H. G. Adolph, J. Org. Chem., 1982, 47, 2474.
3ꢀAzidoꢀ1,3ꢀdinitroazetidine (11). IR, ν/cm–1: 2135 (N3);
1576 (N—NO2); 1561 (C—NO2); 1352 (C—NO2); 1342
Received March 25, 2009;
in revised form October 13, 2009