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Organic & Biomolecular Chemistry
Page 3 of 5
DOI: 10.1039/C8OB02155D
Journal Name
COMMUNICATION
C=N bonds, both two compounds exhibit high positive heats of added. Glyoxal (40%, 3.63 g) was slowly added into the mixture,
formation of 999.8 and 823.0 kJ mol‐1.
when the temperature rose to 60 °C. After 0.5 h without cooling to
room temperature, the precipitate was collected, washed with
water, and dried in air to give compound 2 (4.9 g, 0.022 mol, yield:
88.3%). Td: 230 °C. 1H NMR (DMSO‐d6, 500 MHz): δ 7.78 (s, 4H, NH),
4.88 (s, 4H, CH2) ppm. 13C NMR (DMSO‐d6, 500 MHz): δ 147.22
58.99 ppm. IR (KBr): 3313 1579 1324 1288 1128 1080 1020 991 900
824 788 741 697 641 cm‐1. Elemental analysis calcd for C6H6N8O2
(222.17): C 32.44, H 2.72, N 50.44 %; found C 32.21, H 2.80, N
50.29 %.
Compound 3: Compound 2 (2.2 g, 0.01 mol) was slowly added into
the mixture of acetic anhydride (4 ml) and nitric acid (98%, 2 ml) at
0 °C. Keeping the temperature between 0 to 5 °C for 1 h, the white
precipitate was collected to obtain compound 3 (1.5 g, 0.007 mol,
yield: 70.2%). Td: 145 °C. 1H NMR (DMSO‐d6, 500 MHz): 4.32 (s, 2H,
NH). 13C NMR (DMSO‐d6, 500 MHz): δ 160.35 152.75 148.40 142.53
ppm. IR (KBr): 3085 2879 2789 1704 1650 1616 1565 1488 1452
1401 1384 1315 1290 1013 878 837 770 678 636 cm‐1. Elemental
analysis calcd for C6H2N8O2 (218.14): C 33.04, H 0.92, N 51.37 %;
found C 33.25, H 0.84, N 51.55 %.
Table 2. Physiochemical properties and detonation parameters of 2 and 3
compared with TNT and TATB.
a
Compd
Td
db
ΔHfc
Dd
Pe
ISf
FSg
[°C]
230
145
295
330
[g cm-3]
1.800
1.856
1.650
1.930
[kJ mol-1]
999.8
823.0
-59.4
[m s-1]
8143
7652
6881
8114
[GPa]
29.4
26.4
19.5
31.2
[J]
[N]
2
>40
>40
15
>360
>360
353
3
TNTh
TATBh
-154.2
50
>360
[a] Thermal decomposition temperature (DSC, onset, 5 °C min-1). [b] Crystal
density at 298 K. ρ298K = ρT/(1+αv(298-T)); αv = 1.5×10-4 K-1. [c] Calculated
heats of formation (Gaussian 0910). [d] Detonation velocity (K-J equation11).
[e] Detonation pressure (K-J equation). [f] Impact sensitivity. [g] Friction
sensitivity. [h] Ref 7c.
Compound 4: Compound 3 (2.2 g, 0.01 mol) was slowly added into
the mixture of H2SO4 (98%, 5 ml) and H2O2 (30%, 3 ml) at 0 °C.
Rising the temperature to 25 °C, the mixture was stirred for 2 h,
which was then poured into ice water. The mixture was extracted
with ethyl acetate for three times, and then washed with brine for
three times. The solvent was removed using vacuum evaporator,
and compound 4 was obtained (1.3 g, 0.008 mol, yield: 40.0%). Td:
With values of densities and heats of formation, detonation
performance of these two compounds were evaluated.
Compound
m s‐1; P: 29.4 GPa) than compound
GPa). Although compound has a lower density than
compound , it exhibits higher heats of formation that may
lead to improved detonation performance. The detonation
performance of compound is comparable to that of TATB,
and both compounds and were better than TNT. To
2
exhibits better detonation performance (D: 8143
3
(D: 7652 m s‐1; P: 26.4
2
3
1
238 °C. H NMR (DMSO‐d6, 500 MHz): 12.86 (s, 2H, NH). 13C NMR
2
(DMSO‐d6, 500 MHz): δ 154.35 144.70 ppm. IR (KBr): 3538 3083
2748 1688 1657 1592 1520 1393 1363 1334 1016 883 837 750 678
606 552 cm‐1. Elemental analysis calcd for C4H2N4O3 (154.09): C
31.18, H 1.31, N 36.36 %; found C 31.32, H 1.44, N 36.21 %.
2
3
understand the safety of these two compounds, their
mechanical sensitivities were tested using standard BAM
method.12 Both compounds
2 and 3 show very insensitive
properties (IS: >40 J, FS: >360 N), which indicates they can be
categorized as insensitive energetic compounds.
Conflicts of interest
There are no conflicts to declare.
Conclusions
In summary, two tetracyclic fused pyrazine‐fused furazans
were synthesized and fully characterized. X‐ray data indicated
that their structures changed from nonplanar to planar after
Acknowledgements
We gratefully acknowledge financial support from the National
dehydrogenation oxidation. The oxidation reaction broke the Natural Science Foundation of China (NSAF, No. U1530101 and
tetracyclic backbone, and led to the formation of a bicyclic
carbonyl compound. Detonation performance and mechanical
sensitivities comparable to TATB indicate their promise as
insensitive energetic materials.
NSFC, No. 21805138). The authors gratefully acknowledge Dr
Zaichao Zhang (Huaiyin Normal University, China) for his
analysis of the crystal structures.
Notes and references
Experimental section
[1] a) H. Gao, J. M. Shreeve, Chem. Rev. 2011, 111, 7377−7436; b)
S. Li, Y. Wang, C. Qi, X. Zhao, J. Zhang, S. Zhang, S. Pang,
Angew. Chem. Int. Ed. 2013, 52, 14031−14035; c) T. M.
Attention
Compounds presented in the paper are explosives. Although
there is no explosion happened in our preparation, safety
protection is strongly encouraged.
Klapo
̈
tke, J. Stierstorfer, J. Am. Chem. Soc. 2009, 131, 1122−
1134; d) D. Fischer, T. M. Klapo
̈
tke, J. Stierstorfer, Angew.
Chem. Int. Ed. 2015, 54, 10299−10302; d) Q. Sun, C. Shen, X.
Li, Q. Lin and M. Lu, Cryst. Growth Des., 2017, 17, 6105‐6110.
[2] a) H. Huang, Y. Shi, Y. Liu, J. Yang, Chem. Asian J. 2016, 11, 1688
–1696; b) K. A. McDonald, S. Seth, A. J. Matzger, Cryst. Growth
Des. 2015, 15, 5963−5972; c) M. Krawiec, S. R. Anderson, P.
Dube, D. D. Ford, J. S. Salan, S. Lenahan, N. Mehta, C. R.
Synthesis
Compound 2: Compound 1 (5.0 g, 0.050 mol) was dispersed in
water (20 ml) at 25 °C, in which hydrochloric acid (37%, 6 ml) was
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