U.S. patent application number 15/060928 was filed with the patent office on 2016-09-15 for synthesis of 3,4-bis(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazole-n-oxide (dntf) using 3-chlorocarbohydroxymoyl-4-nitro-1,2,5-oxadiazole.
This patent application is currently assigned to U.S. Government as Represented by the Secretary of the Army. The applicant listed for this patent is U.S. Government as Represented by the Secretary of the Army. Invention is credited to Reddy S. Damavarapu, Raja G. Duddu, John H. Hoare.
Application Number | 20160264534 15/060928 |
Document ID | / |
Family ID | 56881269 |
Filed Date | 2016-09-15 |
United States Patent
Application |
20160264534 |
Kind Code |
A1 |
Damavarapu; Reddy S. ; et
al. |
September 15, 2016 |
SYNTHESIS OF
3,4-BIS(4-NITRO-1,2,5-OXADIAZOL-3-YL)-1,2,5-OXADIAZOLE-N-OXIDE
(DNTF) USING 3-CHLOROCARBOHYDROXYMOYL-4-NITRO-1,2,5-OXADIAZOLE
Abstract
A novel method for preparing
3-chlorocarbohydroxymoyl-4-nitro-1,2,5-oxadiazole by reacting
4-amino-3-chlorocarbohydroxymoyl-1,2,5-oxadiazole with
H.sub.2O.sub.2 and a tungsten based catalyst and use of the
prepared 3-chlorocarbohydroxymoyl-4-nitro-1,2,5-oxadiazole for
synthesizing
3,4-Bis(4-nitro-1,2,5-oxadizaol-3-yl)-1,2,5-oxadiazole-N-oxide
(DNTF).
Inventors: |
Damavarapu; Reddy S.;
(Hackettstown, NJ) ; Duddu; Raja G.;
(Hackettstown, NJ) ; Hoare; John H.;
(Hackettstown, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
U.S. Government as Represented by the Secretary of the
Army |
Picatinny Arsenal |
NJ |
US |
|
|
Assignee: |
U.S. Government as Represented by
the Secretary of the Army
Picatinny Arsenal
NJ
|
Family ID: |
56881269 |
Appl. No.: |
15/060928 |
Filed: |
March 4, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62131972 |
Mar 12, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C07D 413/14 20130101;
C07D 271/08 20130101 |
International
Class: |
C07D 271/08 20060101
C07D271/08 |
Goverment Interests
RIGHTS OF THE GOVERNMENT
[0002] The inventions described herein may be manufactured and used
by or for the United States Government for government purposes
without payment of any royalties.
Claims
1. The process for preparing
3-chlorohydroximoyl-4-nitro-1,2,5-oxadiazole comprising the steps
of: (a) reacting 4-amino-3-chlorocarbohydroxymoyl-1,2,5-oxadiazole
in the presence of a tungsten based catalyst and aqueous
H.sub.2O.sub.2; (b) heating the solution at greater than 30.degree.
C. to produce 3-amino-4-chlorohydroximoyl 1-2,4-oxadiazole in
solution; (c) isolating the
3-chiorohydroximoyl-4-nitro-1,2,5-oxadiazole from the solution.
2. The process of claim 1 wherein the tungsten based catalyst is
(Bmim).sub.4W.sub.10O.sub.23.
3. The compound, 3-chlorohydroximoyl-4-nitro-1,2,5-oxadiazole,
prepared according to the process of claim 1.
4. A process for preparing
3,4-Bis(4-nitro-1,2,5-oxadizaol-3-yl)-1,2,5-oxadiazole-N-oxide
(DNTF) comprising: (a) dissolving
3-chlorohydroximoyl-4-nitro-1,2,5-oxadiazole prepared according to
the process of claim 1 in diethyl ether; (b) adding drop-wise a
solution of potassium carbonate; (c) stirring the mixture; (d)
isolating the DNTF from the organic layer.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a non-provisional application
that claims the benefit of the provisional patent application
entitled "Synthesis Method for Preparation of
3,4-Bis(4-nitro-t,2,5-oxadizaol-3-yl)-1,2,5-oxadiazole-N-oxide
(DNTF)" filed Mar. 12, 2015, as Ser. No. 62/131,972.
FIELD OF INVENTION
[0003] A process for producing
3,4-Bis(4-nitro-1,2,5-oxadizaol-3-yl)-1,2,5-oxadiazole-N-oxide
(DNTF), an energetic material, through a novel process for
preparing its precursor
3-chlorocarbohydroxymoyl-4-nitro-1,2,5-oxadiazole.
BACKGROUND OF THE INVENTION
[0004] There has been significant research on the synthesis and
development of new energetic materials to meet the needs of U.S.
Department of Defense. it is in this context that research has
focused on a promising melt-castable energetic material
3,4-Bis(4-nitro-1,2,5-oxadizaol-3-yl)-1,2,5-oxadiazole-N-oxide
(DNTF). Synthetic methods for preparing DNTF mainly involve
treating 4-amino-3-chlorocarbohydroxymoyl-1,2,5-oxadiazole (chloro
oxime) (1) with a base followed by extractive work-up to produce
3,4-bis (aminofurazano) furoxan (furoxofurazane) (2). The resulting
furoxofurazane is further oxidized to produce DNTF (4).
[0005] Alternative methods have been explored to prepare a DNTF
precursor by reacting
4-amino-3-chlorocarbohydroxymoyl-1,2,5-oxadiazole (chloro oxime)(1)
with NaNO2 and an acid to convert the amino group in chloro
oxime(1) into the corresponding nitro group in,
3-chlorocarbohydroxymoyl-4-nitro-1,2,5-oxadiazole (3). These
experiments, however, were unsuccessful. Thus, a need exists for
preparing DNTF using alternative methods. Disclosed herein is a
novel method for synthesizing
3-chlorocarbohydroxymoyl-4-nitro-1,2,5-oxadiazole, an intermediate
useful for the preparation of DNTF.
SUMMARY OF THE INVENTION
[0006] A novel process for preparing
3-chlorocarbohydroxymoyl-4-nitro-1,2,5-oxadiazole, a precursor,
using a tungsten catalyst and aqueous H.sub.2O.sub.2 and methods
for synthesizing DNTF using such precursor.
DETAILED DESCRIPTION
[0007] A novel method for synthesis of
3-chlorocarbohydroxymoyl-4-nitro-1,2,5-oxadiazole (3) is disclosed
herein. This compound is further reacted with K2CO3 to produce an
alternative method for preparing the energetic material DNTF as
discussed in further detail below.
##STR00001##
[0008] Preparation of
3-chlorocarbohydroxymoyl-4-nitro-1,2,5-oxadiazole
[0009] 3-chlorocarbohydroxymoyl-4-nitro-1,2, 5-oxadiazole, compound
3, a precursor to DNTF is prepared according to the process
illustrated in schematic 1. The amino group of compound 1 was
subjected to oxidation using aq. 70% H.sub.2O.sub.2 in presence of
a tungsten based catalyst initially at room temperature, followed
by heating at 52.degree. C. for 4 h. An extractive work-up followed
by removal of solvent afforded a pale yellow liquid. Carbon NMR
analysis of this liquid showed a resonance at 158.71 ppm, a triplet
due to coupling of the nitro group nitrogen with ring carbon,
suggesting the formation of the desired nitro compound 3.
[0010] The identity of the liquid, an ethereal solution, was
characterized by reacting it with an aq. potassium carbonate
(K.sub.2CO.sub.3) solution. After stirring the reaction mixture at
room temperature for 2h followed by an extractive workup and
removal of solvent yielded crude DNTF. The crude DNTF was purified
by triturating the crude with diethyl ether, and separation of the
solid via filtration. The spectral and thermal data of the white
solid thus obtained matched with that of the literature reported
values.
[0011] Preparation of
3,4-Bis(4-nitro-1,2,5-oxadizaol-3-yl)-1,2,5-oxadiazole-N-oxide,
(DNTF).
[0012] A heterogeneous mixture of
3-chlorocarbohydroximoyl-4-amino-1,2,5-oxadiazole (400 mg) in 70%
H.sub.2O.sub.2 (10 mL) and (Bmim).sub.4W.sub.10O.sub.23 catalyst
(200 mg) was stirred at room temperature for 16 h and then kept at
52.degree. C. for 4 h. The reaction mixture was diluted with water
(100 mL) and extracted with ethylacetate (3.times.30 mL). The
combined organic layer was washed with water (2.times.50 mL), brine
(1.times.50 mL), dried (Na.sub.2SO.sub.4) and filtered. The
filtrate was evaporated on a rotary evaporator under vacuum at room
temperature to dryness to obtain the product (320 mg, 67% yield) as
a colorless liquid. .sup.1H-NMR (acetone-d.sub.6): 13.03 (br S);
.sup.13C-NMR (acetone-d.sub.6): 123.74, 145.38 and 158.719 (t).
[0013] The product obtained above, i.e.
3-chlorocarbohydroxymoyl-4-nitro-1,2,5-oxadiazole, was used in the
next step without any further purification. The nitro compound (320
mg) was dissolved in diethyl ether (5 ml). To this solution was
added at room temperature drop-wise a solution of potassium
carbonate (166 mg) in water (3 mL). The reaction mixture was then
stirred at room temperature for 2 h. Ether layer was separated and
the aqueous layer was extracted with diethylether (2.times.5 mL).
The combined organic layer was then washed with water (1.times.5
mL), brine (1.times.5 mL), dried (Na2SO.sub.4) and filtered. The
organic solution was evaporated under vacuum at room temperature on
a rotary evaporator. The pale yellow crude solid residue thus
obtained was triturated with ether (1 mL). The white solid was
separated via filtration and air dried. Yield: 68 mg (27% from
nitro derivative) m.p.: 107-108.degree. C. (Lit m.p.
108-110.degree. C.)..sup.1a 13C-NMR (acetone-d.sub.6): 104.45,
138.20, 140.55, 143.83, 160.82 (2 C).
[0014] While embodiments have been set forth as illustrated and
described above, it is recognized that numerous variations may be
made with respect to relative amounts of the constituents in the
composition. Therefore, while the invention has been disclosed
herein, it will be obvious to those skilled in the art that
additions, deletions and modifications can be made without
departing from the spirit and scope of this invention, and no undue
limits should be imposed, except as to those set forth in the
following claims.
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