Synthesis and characterization of secondary nitrosamines from secondary amines using sodium nitrite and p-toluenesulfonic acid

Article abstract of DOI:10.1002/asia.201403182

We synthesized nitrosamines (R₂N-NO) with R = iPr (1), nPr (2), nBu (3), and hydroxyethyl (4) from the amine using sodium nitrite/p-toluenesulfonic acid in CH₂Cl₂. The rate of formation of 1-4 increases in the direction iPr2CH₂OH. Compounds 1-3 were obtained as colorless solids, whereas 4 is a bright yellow liquid. Compounds 1-4 were characterized by elemental analysis, MS, IR, and multinuclear NMR (¹H, ¹³C, and ¹⁵N) spectroscopies. Additionally, we measured the UV/Vis spectra of all compounds, which show maxima of absorption at approximately 221 nm and molar extinction coefficients between 3043 and 4859 Lmol^-1cmr^-1. We calculated the optimized structures of 1-4 (B3LYP/6-311+G(d,p)) and computed the NMR spectroscopic chemical shifts and infrared frequencies. Furthermore, we carried out a natural bond orbital (NBO) analysis of the nitrosamine moiety. Lastly, the compounds described in this work are valuable starting materials for the synthesis of 2-tetrazenes with potential interest to replace highly toxic hydrazines in rocket propulsion.

Full text of DOI:10.1002/asia.201403182

DOI: 10.1002/asia.201403182
Full Paper
Energetic Materials
Synthesis and Characterization of Secondary Nitrosamines from
Secondary Amines Using Sodium Nitrite and p-Toluenesulfonic
Acid
Carles Mirꢀ Sabatꢁ* and Henri Delalu[a]
Abstract: We synthesized nitrosamines (R2NÀNO) with R=
iPr (1), nPr (2), nBu (3), and hydroxyethyl (4) from the amine
using sodium nitrite/p-toluenesulfonic acid in CH2Cl2. The
rate of formation of 1–4 increases in the direction iPr<nPr<
nBu<CH2CH2OH. Compounds 1–3 were obtained as color-
less solids, whereas 4 is a bright yellow liquid. Compounds
1–4 were characterized by elemental analysis, MS, IR, and
multinuclear NMR (1H, 13C, and 15N) spectroscopies. Addition-
ally, we measured the UV/Vis spectra of all compounds,
which show maxima of absorption at approximately 221 nm
and molar extinction coefficients between 3043 and
4859 LmolÀ1 cmÀ1. We calculated the optimized structures of
1–4 (B3LYP/6-311+G(d,p)) and computed the NMR spectro-
scopic chemical shifts and infrared frequencies. Furthermore,
we carried out a natural bond orbital (NBO) analysis of the
nitrosamine moiety. Lastly, the compounds described in this
work are valuable starting materials for the synthesis of 2-
tetrazenes with potential interest to replace highly toxic hy-
drazines in rocket propulsion.
Introduction
corresponding amine (R2NÀH) with either an organic nitrite
(e.g., n-butyl nitrite)[1,2] or an inorganic nitrite (e.g., NaNO2)[3–6]
Nitrosamines are chemical compounds of the formula (R2NÀ in the presence of acid. Nitrosamines are also considered to be
NO, Scheme 1), which are generally carcinogenic but find nev-
ertheless wide synthetic use (e.g., in the rubber industry).
These materials are typically synthesized by the reaction of the
valuable starting materials for the synthesis of hydrazines
through reduction reactions using reagents such as Zn/H+,[7]
Na/NH3(l),[8] LiAlH4,[1,9] or H2/Pd.[10]
Hydrazine (N2H4) and some of their derivatives such as
MeNHÀNH2 (MMH=monomethylhydrazine) or Me2NÀNH2
(UDMH=unsymmetrical dimethylhydrazine) are widely used as
hypergolic bipropellants in combination with oxidizers (e.g.,
WFNA=white fuming nitric acid).[11–13] However, in addition to
the high toxicity and carcinogenic character of high-purity
liquid hydrazines, their vapors might form explosive mixtures
with air.[14]
Recently, we became interested in the potential of using
substituted 2-tetrazenes to form energetic materials with lower
vapor pressures and lower toxicities.[15,16] In particular, 1,1,4,4-
tetramethyl-2-tetrazene (TMTZ; Scheme 2)[16] is a liquid com-
Scheme 1. General synthesis of substituted 2-tetrazenes from secondary
amines (A=nitrosylation, B=reduction, C=oxidation).
Scheme 2. Patented synthesis of 1,1,4,4-tetramethyl-2-tetrazene (TMTZ).[16]
pound, which has generated a great deal of interest among
the energetic materials community owing to its lower vapor
pressure, lower toxicity, and comparable performance as com-
pared to commonly used compounds. TMTZ has been pro-
posed to replace hydrazines in rocket propulsion and is cur-
rently being further studied.[17]
[a] Dr. C. Mirꢀ Sabatꢁ, Dr. H. Delalu
Laboratoire Hydrazines et Composꢁs ðnergꢁtiques Polyazotꢁs
UMR 5278/CNRS/UCBL/CNES/SME-SAFRAN
Universitꢁ Claude Bernard Lyon 1
3ꢂ ꢁtage, 22, av. Gaston Berger, 69622 Villeurbanne (France)
Fax: (+33)472-431-291
E-mail: carlos.miro-sabate@univ-lyon1.fr
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Other 2-tetrazenes of energetic interest that exhibit high
thermal stabilities and low temperatures of explosion have
also been reported recently by the Klapçtke group.[18] These
compounds can be synthesized by oxidation of the corre-
sponding hydrazine with a variety of oxidizing agents (e.g.,
HgO[19] and Br2 or I2).[20]
Our interest in synthesis and in the field of energetic materi-
als prompted us to study the reaction of several secondary
amines with the sodium nitrite/p-toluenesulfonic acid (NaNO2/
p-TSA) system to access the corresponding nitrosamines. We
are currently studying possible reduction reactions of these ni-
trosamines to form secondary hydrazines as prospective valua-
ble intermediates for the synthesis of 2-tetrazenes of energetic
interest.
Scheme 4. Synthesis of nitrosamine 4 using alkyl nitrites in THF.
spective, using NaNO2 and p-TSA (Acros price: 63 and
144 EkgÀ1, respectively) is significantly cheaper than using
alkyl nitrites such as isoamyl nitrite (41 E/100 g) or n-butyl ni-
trite (91 E/100 g).
Results and Discussion
For all compounds in this study we measured the H, 13C,
1
The nitrosamines (R2NÀNO) in this work were synthesized by
the reaction of the corresponding secondary amine (R2NÀH)
with a slight excess amount (typically 1.05 equiv) of the nitro-
sylating system composed of sodium nitrite and p-toluenesul-
fonic acid (NaNO2/p-TSA) in dichloromethane as the solvent.
The substituents (R) chosen for this study were iPr (1), nPr (2),
nBu (3), and hydroxyethyl (4) (Scheme 3). Upon addition of p-
and 15N [1H] NMR spectra (Table 1). The ÀCH3 groups have the
highest field resonances between d=0.83 and 1.31 ppm, fol-
lowed by the ÀCH2À groups in the range d=1.27 to 4.18 ppm.
The ÀCHÀ moiety of compound 1 resonates at d=3.32 ppm
and the ÀOH proton of nitrosamine 4 at d=4.85 ppm. Note
that the latter compound shows a doublet of resonances for
the two ÀCH2À moieties in the molecule (also observed in the
13C NMR spectrum). In the 13C NMR spectra the groups above
show chemical shifts in the range d=10.86–17.85 ppm (ÀCH3)
and d=19.18–58.84 ppm (ÀCH2À), whereas the ÀCHÀ carbon
atom in compound 1 resonates at d=46.06 ppm. Note that ni-
trosamine 4 shows two sets of two signals for the two ÀCH2À
1
groups in both the H and the 13C NMR spectra. The 15N [1H]
NMR spectroscopic shifts for the two nitrogen atoms appear at
around d=538 ppm (NÀNO) and d=250 ppm (NÀNO) for all
four compounds (NH3 as external standard). All these chemical
shifts are consistent with literature data[21] and in relatively
good agreement with the calculated values reported in Table 1
(values calculated in [D6]DMSO using B3LYP/6-311+G(d,p)).
The UV/Vis absorption spectra of solutions of nitrosamines
1–4 in water were measured and are represented in Figure 1.
Scheme 3. Synthesis of secondary nitrosamines 1–4 using the NaNO2/p-TSA
system.
toluenesulfonic acid, immediate precipitation of sodium p-tol-
uenesulfonate is observed. The rate of reaction is dependent
on the R substituent of the secondary amine and the reaction
time was monitored by means of gas chromatography. The
rate of formation of the nitrosamines increases in the order
iPr<nPr<nBu<CH2CH2OH. Additionally, compound 4 was
also synthesized according to a reported method[1] by using n-
butyl nitrite as the nitrosylating agent in THF (Scheme 4). After
filtering and stripping the solvent, compounds 1–4 were either
obtained as oils, which crystallized into colorless powders
upon standing (compounds 1–3) or as a bright yellow oil,
which stayed liquid (nitrosamine 4). Compounds 1–4 are
highly soluble in polar solvents such as water, DMSO, or ace-
tone, soluble in dichloromethane, and insoluble in ether.
Figure 1. UV/Vis spectra of nitrosamines 1–4 in water.
These spectra are characterized by one maximum of absorp-
tion (lmax) at approximately 221 nm and molar extinction coef-
ficients (e) in the range 3043 (nitrosamine 3) to
4859 LmolÀ1 cmÀ1 (nitrosamine 1). This absorption corresponds
to the p-to-p* transition and is found at similar values to those
reported for other nitrosamines.[21]
The purpose of using the NaNO2/p-TSA to nitrosylate the
secondary amines in this work was twofold. Firstly, this system
uses mild conditions and affords pure product without further
purification. And secondly, from a large-scale synthesis per-
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Table 1. NMR spectroscopic data [ppm] for compounds 1–4 with 3J(H,H) coupling constants [Hz] in parentheses. NH3 as external standard for the 15N{1H}
NMR spectroscopic shifts. The calculated shifts are indicated in brackets.[a]
1H
Compound
-CH-
-CH2-
-CH2-
-CH2-
-CH3
-OH
1
2
3
4
3.32, (6.4), [3.72]
1.31, (6.4), [1.03]
0.83, (7.6), [0.79]
0.84, (7.6), [0.99]
2.80, (7.6), [3.17]
2.87, (7.6), [3.14]
3.72, (5.6), [3.91]
4.18, (6.0), [3.91]
1.66, (7.6), [1.62]
1.68, (7.6), [1.59]
3.45, (5.6), [3.23]
3.66, (6.0), [3.23]
1.27, (7.6), [1.22]
4.85, [3.40]
Compound
13C
-CH-
-CH2-
-CH2-
-CH2-
-CH3
1
2
3
4
46.06, [46.07]
17.85, [17.96]
10.86, [11.88]
13.44, [13.95]
49.25, [56.10]
47.60, [54.21]
56.92, [63.02]
58.84, [63.02]
19.18, [24.14]
27.66, [33.56]
46.62, [54.80]
55.19, [54.80]
19.85, [24.80]
Compound
15N{1H}
NÀNO
NÀNO
1
2
3
4
538.27, [613.41]
249.12, [313.16]
255.12, [303.80]
252.01, [302.59]
249.25, [291.17]
537.20, [595.66]
538.18, [594.87]
538.08, [600.62]
[a] Values calculated in [D6]DMSO (B3LYP/6-311+G(d,p)).
The harmonic vibrational frequencies of the nitrosamines in
this work were calculated (B3LYP/6-311+G(d,p)) using Gaussi-
an.[22] The experimental frequencies are in fair agreement with
the calculated values. In the infrared spectra compounds 1–3
exhibit a set of strong bands, which appear consistently in the
range 1000 to 1230 cmÀ1. Many of these signals are missing in
the infrared spectrum of nitrosamine 4. These signals can be
assigned to a combination of vibrational modes including CÀC
stretching and rocking, twisting, and wagging vibrations of the
CH2 and CH3 (compound 1) moieties. The strongest signals in
the spectra of 1–3 are two bands at approximately 560 and
680 cmÀ1, respectively (535 and 657 cmÀ1 for compound 4).
According to our Gaussian calculations, the former corre-
sponds to breathing modes of the [R2NÀN] moiety, whereas
the latter correspond to CH2 (CH3 for nitrosamine 1) rocking
modes. The NÀN stretching modes are found experimentally at
approximately 1030 cmÀ1 at lower wavenumbers than the cal-
culated values (approximately 1070 cmÀ1), and the N=O
stretching vibrations are observed in the range 1530 to
1600 cmÀ1 (calculated at 1520 to 1540 cmÀ1).[23]
Figure 2. Optimized structures of nitrosamines 1–4 (B3LYP/6-311+G(d,p).
We carried out a natural bond orbital (NBO) analysis of the
optimized structure of nitrosamines 1–4 using the B3LYP
method with a 6-311+G(d,p) basis set[22] to gain a better un-
derstanding of the charge distribution in this type of com-
pounds. Selected calculated NBO charges for the nitrosamine
moiety are collected in Table 3. The oxygen atom O5 holds the
most negative NBO charge at around À0.480e for compounds
1–3. This oxygen atom is expected to be involved in hydrogen
bonding in the solid state. In the structure of compound 4
(which contains two hydroxyl groups) the ÀOH oxygen atom
(O6) bears the most negative NBO charge (À0.820e) and, ac-
cording to our calculations, it forms an intramolecular hydro-
gen bond with the second hydroxyl group in the molecule
with a donor–acceptor distance (O7ÀO6) of 2.876 ꢃ, a hydro-
Figure 2 shows the optimized structures of nitrosamines 1–4
using B3LYP at the 6-311+G(d,p) level of theory. Table 2 con-
tains a summary of the bond distances and angles of the ni-
trosamine moiety in compounds 1–4. The C-N-N-O substruc-
ture is calculated to be nearly planar with dihedral angles
close to 08. The C1ÀN3 and C2ÀN3 distances are in the range
between 1.460 and 1.490 ꢃ close to the average s CÀN bond
distance (1.47 ꢃ). The N3ÀN4 bond exhibits some double-bond
character with a distance of approximately 1.33 ꢃ in between
the average NÀN (1.40 ꢃ) s bond and the average N=N
(1.20 ꢃ) p bonds, whereas the N4ÀO5 bond has a strong
double-bond character with a distance of 1.22 ꢃ (NÀO=1.36 ꢃ
and N=O=1.15 ꢃ).[24]
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the infrared frequencies, NMR spectroscopic chemical shifts,
and NBO charges. Currently we are exploring methods for the
reduction of the nitrosamines in this study to form the corre-
sponding hydrazines, which will later be oxidized to form 2-tet-
razenes of potential interest in liquid rocket propulsion.
Table 2. Optimized structure parameters of the NÀN core in nitrosamines
1–4 in the gas phase (B3LYP/6-311+G(d,p)).[a]
1
2
3
4
Experimental Section
R(C1ÀN3)
1.482
1.490
1.323
1.230
119.0
116.8
124.1
116.3
0.9
1.460
1.467
1.333
1.225
115.9
122.4
121.4
115.6
177.6
À3.4
1.461
1.468
1.332
1.225
115.9
122.3
121.5
115.6
177.3
3.1
1.463
1.465
1.334
1.225
115.8
122.7
120.6
115.3
173.8
4.2
All chemical reagents and solvents of analytical grade were ob-
tained from Sigma–Aldrich Inc. or Acros Organics and used as sup-
R(C2ÀN3)
R(N3ÀN4)
1
plied. H, 13C, and 15N [1H] NMR spectra were recorded with a JEOL
R(N4ÀO5)
Eclipse 400 instrument. The chemical shifts are given relative to
tetramethylsilane (1H and 13C NMR spectroscopy) or ammonia
(15N NMR spectroscopy) as external standards. Infrared (IR) spectra
were recorded at room temperature with a Perkin–Elmer Spectrum
instrument equipped with a Universal ATR sampling accessory. IR
intensities are given in parentheses. Raman activities are reported
in percentages relative to the most intense peak and are given in
parentheses. Elemental analyses were performed with a Netsch Si-
multanous Thermal Analyzer STA 429.
A(C1-N3-C2)
A(C1-N3-C2)
A(C1-N3-N4)
A(N3-N4-O5)
A(C1-N3-N4-O5)
A(C2-N3-N4-O5)
179.4
[a] R=bond length [ꢃ]; A=bond angle [8].
Table 3. NBO charges [e] of nitrosamines 1–4 (B3LYP/6-311+G(d,p)).
General Method for the Preparation of Nitrosamines 1–4
Using the NaNO2/p-TSA System
A suitable secondary amine (typically between 5 and 100 mmol)
was dissolved in dichloromethane (between 10 and 200 mL), and
an excess amount of sodium nitrite (between 5.25 and 105 mmol)
was added. The suspension was stirred efficiently, and p-toluene-
sulfonic acid monohydrate (between 5.25 and 105 mmol) was
added portion-wise at room temperature. The resulting suspension
was then stirred strongly and monitored by gas chromatography
(typical reaction time between 1 and 12 h). When the reaction was
complete, the insolubles were filtered and washed with fresh di-
chloromethane. The dichloromethane fractions were then com-
bined and rotavaporated to dryness at 308C.
1
2
3
4
C1
C2
N3
N4
O5
À0.082
À0.269
À0.267
À0.300
À0.251
À0.329
+0.200
À0.468
À0.234
À0.106
+0.189
À0.490
À0.236
À0.302
+0.192
À0.478
À0.234
À0.302
+0.191
À0.480
gen-acceptor distance (HÀO7) of 1.974 ꢃ and a O7-H-O6 angle
of 153.98. The nitrosamine nitrogen atom (N4) bears a consis-
tent NBO charge in all four compounds of approximately
+0.190e, whereas N3 has a charge of approximately À0.300e
for compounds 2–4 (À0.106e for nitrosamine 1). The carbon
atoms in the vicinity of the nitrosamine moiety (C1 and C2)
have negative NBO charges at approximately À0.250e. Lastly,
the relatively small (positive) charge on N4 might be indicative
of the difficulty to reduce this nitrogen atom to form the corre-
sponding hydrazine. We are currently working on finding suita-
ble experimental conditions to carry out this transformation.
Nitrosodiisopropylamine (1)
1
Colorless solid (98% yield). H NMR ([D6]DMSO, 400.13 MHz, TMS):
d=1.31 (d, 3J(H,H)=6.4 Hz, 6H; ÀCH3), 3.32 ppm (sept, 3J(H,H)=
6.4 Hz, 1H; ÀCHÀ); 13C{1H} NMR ([D6]DMSO, 100.52 MHz, TMS): d=
17.85 (2C; ÀCH3), 46.06 ppm (1C; ÀCHÀ); 15N{1H} NMR ([D6]DMSO,
50.68 MHz, NH3): d=514.92 (1N; NÀNO), 267.34 ppm (1N; NÀNO);
IR (golden gate, rel. int.): n˜ =3055 (w), 2978 (w), 2865 (m), 1591
(m), 1490 (w), 1470 (m), 1375 (w), 1225 (s), 1170 (s), 1142 (s), 1110
(s), 1027 (s), 1004 (s), 842 (w), 818 (w), 717 (w), 684 (vs), 561 (vs),
471 cmÀ1 (w); UV/Vis (H2O, 1.77ꢄ10À4 m): lmax =222 nm (e=
4859 LmolÀ1 cmÀ1); GC–MS (ESI): m/z (%): 15.2 (3) [ÀMe], 27.2 (8),
30.2 (5) [ÀNO], 43.2 (100) [iPr], 58.2 (24) [HN(iPr)], 70.2 (73)
[MÀ4Me], 84.2 (13), 113.2 (6), 130.2 (96) [M]; elemental analysis
calcd (%) for C6H14N2O (130.19 gmolÀ1): C 55.35, H 10.84, N 21.52;
found: C 55.59, H 10.75, N 21.56.
Conclusion
In this work we present the synthesis of four nitrosamines with
different substituents (compounds 1–4) using the sodium ni-
trite/p-toluenesulfonic acid system in dichloromethane. The
rate of formation was monitored by gas chromatography and
increases in the order iPr<nPr<nBu<CH2CH2OH. Nitrosa-
mines 1–4 were characterized by elemental analysis, mass
spectrometry, infrared, UV/Vis, and multinuclear NMR (1H, 13C,
and 15N) spectroscopies. Additionally, we optimized the gas-
phase structure of the compounds using the B3LYP method
with a 6-311+G(d,p) basis set and used this structure to predict
Nitrosodi-n-propylamine (2)
1
Colorless solid (quant. yield). H NMR ([D6]DMSO, 400.13 MHz, TMS):
d=0.83 (t, 3J(H,H)=7.6 Hz, 3H; ÀCH3), 1.66 (sext, 3J(H,H)=7.6 Hz,
3
2H; ÀCH2À), 2.80 ppm (t, J(H,H)=7.6 Hz, 2H; ÀCH2À); 13C{1H} NMR
([D6]DMSO, 100.52 MHz, TMS): d=10.86 (1C; ÀCH3), 19.18 (1C;
ÀCH2À), 49.25 ppm (1C; ÀCH2N); 15N{1H} NMR ([D6]DMSO,
50.68 MHz, NH3): d=537.20 (1N; NÀNO), 255.12 ppm (1N; NÀNO);
IR (golden gate, rel. int.): n˜ =3024 (w), 2988 (m), 2861 (m), 2778
(w), 2507 (w), 2233 (w), 1601 (m), 1495 (w), 1472 (m), 1454 (w),
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1397 (m), 1379 (m), 1327 (w), 1304 (w), 1229 (s), 1179 (m), 1151 (s),
1119 (s), 1106 (s), 1030 (s), 1007 (s), 952 (w), 855 (w), 826 (m), 812
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(H2O,
2.04ꢄ10À4 m):
lmax =221 nm
(e=
3961 LmolÀ1 cmÀ1); GC–MS (ESI): m/z (%): 15.2 (2) [ÀMe], 27.2 (7),
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Nitrosodi-n-butylamine (3)
1
Colorless solid (96% yield). H NMR ([D6]DMSO, 400.13 MHz, TMS):
d=0.84 (t, 3J(H,H)=7.6 Hz, 3H; ÀCH3), 1.27 (sext, 3J(H,H)=7.6 Hz,
3
2H; ÀCH2À), 1.68 (quint., J(H,H)=7.6 Hz, 2H; ÀCH2À), 2.87 ppm (t,
3J(H,H)=7.6 Hz, 2H; ÀCH2À); 13C{1H} NMR ([D6]DMSO, 100.52 MHz,
TMS): d=13.44 (1C; ÀCH3), 19.85 (1C; ÀCH2À), 27.66 (1C; ÀCH2À),
47.60 ppm (1C; ÀCH2N); 15N{1H} NMR ([D6]DMSO, 50.68 MHz, NH3):
d=538.18 (1N; NÀNO), 252.01 ppm (1N; NÀNO); IR (golden gate,
rel. int.): n˜ =3116 (w), 3060 (w), 2955 (m), 2930 (w), 2870 (m), 1978
(w), 1570 (w), 1496 (w), 1469 (m), 1374 (w), 1219 (s), 1166 (s), 1121
(s), 1106 (m), 1034 (s), 1009 (s), 846 (w), 817 (m), 799 (w), 768 (m),
740 (w), 712 (w), 681 (vs), 565 (vs), 550 (m), 501 (w), 472 cmÀ1 (w);
UV/Vis (H2O, 2.53ꢄ10À4 m): lmax =221 nm (e=3043 LmolÀ1 cmÀ1);
ESI (c): m/z (%): 148.2 (100) [M]+, 449.3 (75), 750.5 (45); elemental
analysis calcd (%) for C8H8N2O (148.16 gmolÀ1): C 64.85, H 5.44, N
18.91; found: C 64.79, H 5.28, N 18.70.
[16] C. Mirꢀ Sabatꢁ, H. Delalu, Y. Guelou, A. Dhenain, G. Jacob, FR1153221,
2011.
[17] a) G. Jacob, J. F. Guery, A. J. Bougrine, H. Delalu, E. Labarthe, Y. Guelou,
M. Guitton, C. Kappensein, Space Propulsion 2012, Bordeaux, May 2012;
b) C. Mirꢀ Sabatꢁ, H. Delalu, Space Propulsion 2014, Cologne, May 2014.
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b) H. W. Kruse, W. R. Mcbride, US 3135800, 1964.
Nitrosodiethanolamine (4)
Compound 4 was synthesized by the method indicated above and
following the procedure of Porath et al. from diethanolamine and
n-butyl nitrite[1] to give comparable results. Bright yellow oil (96%
yield). 1H NMR ([D6]DMSO, 400.13 MHz, TMS): d=3.45 (t, 3J(H,H)=
5.6 Hz, 2H; ÀNCH2), 3.66 (t, 3J(H,H)=6.0 Hz, 2H; ÀNCH2), 3.72 (t,
3J(H,H)=5.6 Hz, 2H; ÀOCH2), 4.18 (t, 3J(H,H)=6.0 Hz, 2H; ÀOCH2),
4.85 ppm (brs, 2H; ÀOH); 13C{1H} NMR ([D6]DMSO, 100.52 MHz,
TMS): d=46.62 (1C; ÀNCH2), 55.19 (1C; ÀNCH2), 56.92 (1C;
ÀOCH2), 58.84 ppm (1C; ÀOCH2); 15N{1H} NMR ([D6]DMSO,
50.68 MHz, NH3): d=538.08 (1N; NÀNO), 249.25 ppm (1N; NÀNO);
IR (golden gate, rel. int.): n˜ =3342 (m), 2944 (w), 2886 (w), 1532
(m), 1448 (m), 1426 (m), 1354 (s), 1330 (s), 1300 (s), 1156 (m) 1037
(vs), 862 (m), 776 (m), 657 (m), 535 (m), 479 (w), 464 cmÀ1 (w); UV/
Vis (H2O, 1.87ꢄ10À4 m): lmax =221 nm (e=4277 LmolÀ1 cmÀ1); ESI (+
c): m/z (%): 102.1 (44), 106.1 (80), 150.1 (22), 193.2 (34), 239.8 (100),
306.8 (28); ESI (Àc): m/z (%): 169.1 (12) [M+Cl]À, 195.9 (100), 302.7
(28), 329.6 (24), 409.1 (11); elemental analysis calcd (%) for
C4H10N2O3 (134.13 gmolÀ1): C 35.82, H 7.51, N 20.88; found: C
35.59, H 7.37, N 20.56.
[21] E. Pretsch, P. Bꢅhlmann, Structure Determination of Organic Compounds:
Tables of Spectral Data, 4th ed., Springer, New York, 2009.
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Acknowledgements
Financial support from the Centre National de la Recherche
Scientifique (CNRS) and the University Claude Bernard of Lyon
are gratefully acknowledged.
[24] A. F. Hollemann, E. Wieberg, N. Wieberg, Lehrbuch der Anorganischen
Chemie, 101th ed., Walter de Gruyter, Berlin, 1995.
Keywords: amines · energetic materials · hydrazines · sodium ·
Received: October 14, 2014
synthetic methods
Published online on && &&, 0000
Chem. Asian J. 2015, 00, 0 – 0
www.chemasianj.org
5
ꢂ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
&
&
These are not the final page numbers! ÞÞ

Full Paper
FULL PAPER
Energetic Materials
Rocket science: This manuscript de-
scribes the synthesis and characteriza-
tion of several nitrosamines (see
scheme), which are useful starting mate-
rials for the synthesis of 2-tetrazenes of
prospective interest in liquid rocket pro-
pulsion.
Carles Mirꢀ Sabatꢁ,* Henri Delalu
&& – &&
Synthesis and Characterization of
Secondary Nitrosamines from
Secondary Amines Using Sodium
Nitrite and p-Toluenesulfonic Acid
&
&
Chem. Asian J. 2015, 00, 0 – 0
www.chemasianj.org
6
ꢂ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ÝÝ These are not the final page numbers!