3,6-Bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,4,2,5-dioxadiazene (BNDD): A Powerful Sensitive Explosive

Article abstract of DOI:10.1055/s-0030-1261169

The explosive 3,6-bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,4,2,5-dioxadiazene (BNDD) was synthesized by oxidation of the corresponding diamine using hydrogen peroxide in sulfuric acid with sodium tungstate. The product exhibited detonations during sensitivity testing at low insult; the material is shock and friction sensitive. The synthesis of BNDD should only be pursued by knowledgeable researchers exercising extreme caution.

Full text of DOI:10.1055/s-0030-1261169

LETTER
2097
3
,6-Bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,4,2,5-dioxadiazene (BNDD):
A Powerful Sensitive Explosive
a
a
a
b
c
B
P
N
D
D:
A
P
ow
h
erful Sensit
il
losiveip W. Leonard,* Colin J. Pollard, David E. Chavez, Betsy M. Rice, Damon A. Parrish
a
b
c
Los Alamos National Laboratory, Weapons Experiments Division, Los Alamos, NM 87545, USA
Army Research Laboratory, Aberdeen Proving Grounds, Aberdeen, MD 20783, USA
Naval Research Laboratory, Laboratory for the Structure of Matter, Washington, DC 20375, USA
Fax +1(505)6670500; E-mail: philipl@lanl.gov
Received 23 May 2011
Synthesis
Abstract: The explosive 3,6-bis(4-nitro-1,2,5-oxadiazol-3-yl)-
1
,4,2,5-dioxadiazene (BNDD) was synthesized by oxidation of the As shown in Scheme 1, from 4-amino-N¢-hydroxy-1,2,5-
corresponding diamine using hydrogen peroxide in sulfuric acid
with sodium tungstate. The product exhibited detonations during
sensitivity testing at low insult; the material is shock and friction
sensitive. The synthesis of BNDD should only be pursued by
knowledgeable researchers exercising extreme caution.
oxadiazole-3-carboximidamide (3), the corresponding
imidoyl chloride, 4, was formed by diazotization in aque-
ous HCl. The product was recovered in good yield and pu-
rity; however, it is a strong irritant to the skin and an
inhalation hazard. Deprotonation of 4 in DMSO using
aqueous sodium carbonate accomplishes selective dimer-
ization to the dioxadiazene, 5, through the intermediacy of
Key words: explosives, furazan, heterocycles, nitrogen, oxidation
6
the nitrile oxide. This outcome is in contrast to the same
Considerable interest has been given to the explosive ma-
terial 3,4-bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,5-oxadia-
zole 2-oxide [BNFF (2)] as a new potential main charge
reaction performed in a biphasic mixture of diethyl ether
and water which provided primarily 6 (BAFF), with 5 as
7
a significant contaminant. More polar organic solvents,
1
–3
explosive. BNFF, in older papers referred to as DNTF,
has a high density (1.94 g/cc) and a high enthalpy of for-
mation, implying strong performance. Sensitivity testing
at Los Alamos National Laboratory (LANL) revealed that
BNFF has an undesirable response to impact being con-
siderably more sensitive than RDX as shown in Table 1.
Consequently we endeavored to synthesize the constitu-
tional isomer of BNFF, 3,6-bis(4-nitro-1,2,5-oxadiazol-3-
yl)-1,4,2,5-dioxadiazene [BNDD (1), Figure 1] in the
hopes of discovering a less sensitive but equally energetic
material. BNDD has been mentioned in one patent and
including DMSO, encourage formation of 5 as discussed
by Lim et al. Amine oxidation of the dioxadiazene isomer
2
to the corresponding dinitro derivative 1 is notably more
difficult than the equivalent transformation to make
BNFF. Application of hydrogen peroxide in trifluoroace-
tic acid to 5 resulted only in the recovery of starting mate-
rial whereas these conditions are sufficient to make BNFF
in good yield. From Sheremetev’s methods we ultimately
ascended to the vigorous oxidant mixture of 90% hydro-
8
gen peroxide and sodium tungstate in sulfuric acid. A
considerable excess of sodium tungstate, added in stages,
was required to drive the oxidation reaction to comple-
tion. Temperature control was critical as the reaction
4
one unpublished report. Energetic derivatives of the cor-
responding diamine [BADD (5), Scheme 1] have been
5
published however no detailed report of the sensitivity or
thermodynamic properties of 1 was previously available
in the open literature.
O
O
N
N
N
N
NaNO2
NH2
Cl
H2N
HCl H2N
O
N
N
N
O
O
N
OH
OH
O
O
N
N
N
N
N
N
O2N
N
3
4 71%
N
NO2
O2N
NO2
Na2CO3
DMSO
N
O
N
O
O
O
N
O
O
N
N
N
N
N
N
BNDD (1)
BNFF (2)
N
O
O
H2N
N
N
+
Figure 1 The isomeric explosives BNDD (1) and BNFF (2)
H2N
NH2
N
NH2
O
O
N
O
BADD (5) 53%
BAFF (6) trace
TFAA, H2O2
H2SO4, H2O2, Na2WO4
SYNLETT 2011, No. 14, pp 2097–2099
x
x
.x
x
.2
0
1
1
BNDD (1) 70%
BNFF (2) 65%
Advanced online publication: 10.08.2011
DOI: 10.1055/s-0030-1261169; Art ID: S04611ST
Scheme 1 Synthesis of nitrofurazans 1 and 2
©
Georg Thieme Verlag Stuttgart · New York

2
098
P. W. Leonard et al.
LETTER
would either fail to go to complete conversion or overheat After six impacts during drop hammer testing it was dis-
and destructively outgas if improperly managed. Once covered that both the anvil and striker of the impact test-
proper conditions were discovered, isolation of the prod- ing apparatus had been fractured. Photographs of the
uct was accomplished by quenching into water followed damage to the striker are shown in Figure 2. Although not
by filtration.
unheard of, this type of damage to the impact testing
equipment is unusual and is generally indicative of mate-
rial with a high detonation velocity.
Physical Properties
1
3
BNDD is a white odorless crystalline powder. C NMR
gives the expected three signals; d = 139.7 and 152.4 ppm
X-ray Crystallography
and a broad resonance at 159.9 ppm. After initial sensitiv- X-ray quality crystals were grown from acetone by slow
ity testing we elected not to scaleup BNDD beyond gram evaporation of the mother liquor. The structure of BNDD
quantities. BNDD was more sensitive to impact and spark is shown in Figure 3; a quantitative description of the
than PETN run on the same instrument under the same structure is complicated by the fact that the unit cell con-
conditions (see Table 1). Striking more than 10 mg of tains two non-identical conformers. Notable in this struc-
BNDD on a metal anvil with a hammer resulted in an in- ture is the bending of the central six-membered, formally
credibly loud report (hearing protection is strongly recom- antiaromatic, ring into a twist-boat conformation, the av-
mended). Preliminary D 50 measurements on a type 12 erage C–N–O–C torsion angle is 24.37° (averaged across
H
drop weight impact apparatus using the Neyer D-optimal both conformers). It is also noteworthy that the nitrofura-
method for statistical sampling gave a drop height of 8.8 zanyl moieties are skewed with respect to the central ring
cm, corresponding to an impact energy of 2.2 joules. implying that p-conjugation among the three electron-
Scraping the material never accomplished audible or visu- deficient rings is unfavorable. In both conformers one
al evidence of initiation, however BNDD evinced a fric- nitrofurazanyl substituent is nearly perpendicular to the
tion sensitivity of 116 N on the BAM friction test. central ring (e.g. O1A–C6A–C7A–C11A = 82.7° in the
Electrostatic discharge testing at LANL is expressed as conformer shown) while the other torsion angle is more
the 3.4% threshold initiation level (TIL) for detonation. acute, O4A–C3A–C15A–C19A = 60.8°. The inter-ring
For BNDD the TIL was below 0.0625 J, a highly spark- torsion angles and the bent central ring suggest a high de-
sensitive compound. It should be noted that although the gree of electronic localization in BNDD.
sensitivity of BNDD is significantly less than that of most
primary explosives (e.g., lead azide) every event in spark,
friction, and impact testing at the lowest insult was a
‘
high-order’ detonation. As many materials show a graded
response based on severity of insult, BNDD is especially
hazardous because it is in exception to the normal insult-
response relationship.
Table 1 Comparative Sensitivity of BNDD to PETN and RDX
b
Material
Impact DH Friction
Spark ABL
Exo. onset/
a
50 [J]
BAM [N] 3.4% TIL [J] peak DSC [°C]
BNDD
BNFF
PETN
2.2
116
213
110
180
<0.0625
0.0625
0.0625
0.125
148/198
241/275
168/205
200/217
3.1
2.7
RDX
14.7
a
Threshold initiation level.
Exo = exothermal.
b
Figure 3 ORTEP plot of BNDD, ellipsoids at 50% probability level
–1
The density of BNDD changed from 1.93 g cm at –173
C to 1.87 g cm–1 at 295 °C; performance calculations
°
used the lower room temperature value as the theoretical
maximum density (TMD). For details concerning the X-
Figure 2 Damage to the impact testing striker
Synlett 2011, No. 14, 2097–2099 © Thieme Stuttgart · New York

LETTER
BNDD: A Powerful Sensitive Explosive
2099
ray structure see the supplementary information and has been authored by employees of the Los Alamos National Secu-
9
rity, LLC. (LANS), operator of the Los Alamos National Laborato-
ry under Contract No. DE-AC52-06NA25396 with the U.S.
Department of Energy. Released for unlimited audience: LA-UR
11-00570.
CCDC listing.
Calorimetry and Heat of Formation
Performance predictions require an estimate of density
References and Notes
and heat of formation (DH ). For the purpose of perform-
f
ing calorimetry, pressed pellets are preferred in order to
consolidate the material and to initiate a thorough burn.
Pressing BNDD into calorimetry pellets was not per-
formed for safety reasons. Consequently the heat of for-
mation was calculated for 1 and 5 using a quantum
mechanically based approach described previously. The
calculations predicted the diamine 5 to have a solid-state
(
1) Feng-qi, Z.; Pei, C.; Rong-zu, H.; Yang, L.; Zhi-zhong, Z.;
Yan-shui, Z.; Xu-wu, Y.; Yin, G.; Sheng-li, G.; Qi-zhen, S.
J. Hazard. Mater. 2004, A113, 67.
(2) Lim, C. H.; Kim, T. K.; Kim, K. H.; Chung, K.; Kim, J. S.
Bull. Korean Chem. Soc. 2010, 31, 1400.
10
(3) Wang, Q. Chin. J. Propellants Explosives 2003, 3, 57.
(
4) (a) Pirogov, S. V.; Kots, A. Y.; Mel’nikova, S. F.; Postnikov,
A. B.; Betin, V. L.; Shmal’gauzen, E. V.; Khropov, Y. V.;
Muronets, V. I.; Tselinskii, I. V.; Bulargina, T. V. Russ.
Patent 2212409, 2003. (b) Sleadd, B. Private
Communication, 2011.
DH of 117 kcal/mol and 144.8 kcal/mol for BNDD. The
f
heat of formation of BADD was measured at 110 kcal/
1
2
mol. It is not unusual for the calculated value to be high-
er than experiment as a quantitative burn is rarely
achieved, quantification of residual matter is difficult, and
the system is not perfectly adiabatic. Calorimetry on
BNDD was attempted by consolidating the powder in the
bottom of the crucible with solvent and then allowing the
(5) Shaposhnikov, S. D.; Romanova, T. V.; Spiridonova, N. P.;
Mel’nikova, S. F.; Tselinskii, I. V. Zh. Org. Khim. 2004, 40,
922.
(6) Andrianov, V. G.; Semenikhina, V. G.; Eremeev, A. V.
Khim. Geterotsikl. Soedin. 1992, 5, 687.
(7) Wang, J.; Li, J.; Liang, Q.; Huang, Y.; Dong, H. Propellants.
Explos. Pyrotech. 2008, 33, 347.
solvent to evaporate. The DH deduced from that single
f
experiment was 142 kcal/mol, consistent with the calcu-
lated value.
(8) Novikova, T. S.; Mel’nikova, T. M.; Kharitonova, O. V.;
Kulagina, V. O.; Aleksandrova, N. S.; Sheremetev, A. B.;
Pivina, T. S.; Khmel’nitskii, L. I.; Novikov, S. S. Mendeleev
Commun. 1994, 138.
Performance Calculations for BNDD
(9) CCDC No. 825809
10) Byrd, E. F. C.; Rice, B. M. J. Phys. Chem. A. 2006, 110,
(
The performance of BNDD was calculated using the
1005.
1
1
Cheetah thermodynamic code. Calculations support the
qualitative impression from sensitivity testing that BNDD
is a very powerful explosive. At the room temperature
crystal density of 1.87 g/cc BNDD is calculated to have a
detonation velocity of 9040 m/s with a C-J pressure of
(11) Fried, L. A.; Howard, W. M.; Bastea, S.; Glaesmann, K.;
Souers, P. C.; Vitello, P. A.; Kuo, I.-F. CHEETAH
Thermochemical Code; Lawrence Livermore Natl. Lab.:
Livermore CA, 2007.
12) Dong, J.-X.; Li, Q.; Tan, Z.-C.; Zhang, Z.-H.; Liu, Y.
J. Chem. Thermodyn. 2007, 39, 108.
13) Preparation of 3,6-Bis(4-nitro-1,2,5-oxadiazol-3-yl)-
(
3
7.7 GPa. The high brisance predicted by Cheetah is con-
(
sistent with the explosive’s effect on metal parts and its
strong sharp report upon detonation.
1
,4,2,5-dioxadiazine (1): Concentrated sulfuric acid (8 mL,
148 mmol) and anhyd sodium tungstate (1.22 g, 74 mmol)
were combined in a 50-mL round-bottomed flask and stirred.
The flask was suspended in an ice bath. To the acidic
solution, 90% hydrogen peroxide solution (4 mL, 148 mmol)
was added dropwise. The solution was allowed to equilibrate
for 10 min before adding 3,6-bis(4-amino-1,2,5-oxadiazol-
3-yl)-1,4,2,5-dioxadiazine, (5; 1.00 g, 4 mmol) portion-
wise and CH Cl (2 mL) to minimize foaming. The bath
In conclusion, we have synthesized BNDD from the pre-
1
3
viously published BADD and have demonstrated that it
is sufficiently sensitive to be dangerous in contact opera-
tions with more than minimal quantities. In addition,
BNDD is calculated to be a very powerful explosive, ex-
ceeding HMX in C-J pressure and nearly equal in detona-
tion velocity.
2
2
temperature was raised to 15 °C and a Vigreux column with
a drying tube was attached. The solution became green then
faded to an off-white color at which time sodium tungstate
(
0.61 g, 37 mmol) and 90% hydrogen peroxide (2 mL, 74
Supporting Information for this article is available online at
http://www.thieme-connect.com/ejournals/toc/synlett.
mmol) were added. After stirring for 30 min, the reaction
was poured into 250 mL of ice water, stirred for 1 h, and
vacuum filtered. The crude product (1 g) was dissolved into
MeCN (30 mL), stirred for 10 min, and filtered. H O (50
mL) was added to the filtrate with stirring and the resulting
2
Acknowledgment
The authors would like to thank the Los Alamos National Labora-
tory Analytical team, particularly Annie Giambra for Elemental
Analysis, Mary Sandstrom for DSC, and Daniel Preston for impact,
friction, and spark sensitivity testing. This work was funded by the
Joint Munitions Program. Except where indicated, this information
precipitate collected yielding BNDD (1; 0.9 g, 2.9 mmol) in
1
3
70% yield; mp 99 °C. C NMR (DMSO-d
): d = 139.7,
6
152.4, 159.9. IR: 1671, 1587, 1556, 1481, 1088, 1029, 1011,
–
1
861, 825, 764 cm . Anal. Calcd for C
35.90. Found: C, 23.13; N, 36.00.
N O : C, 23.09; N,
8 8
6
Synlett 2011, No. 14, 2097–2099 © Thieme Stuttgart · New York

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