DTIC ADA627559: Solubility Report of 1-Methyl-3,5-Dinitro-1H-1,2,4-Triazole (MDNT) and 2-Methyl-4,5-Dinitro-2H-1,2,3-Triazole 1-Oxide (MDNTO) for Co-Crystallization Screen

UNCLASSIFIED

AD

AD-E403 705

Technical Report ARMET-TR-15028

SOLUBILITY REPORT OF 1-METHYL-3,5-DINITRO-1H-1,2,4-TRIAZOLE
(MDNT) AND 2-METHYL-4,5-DINITRO-2tf-1,2,3-TRIAZOLE 1-OXIDE (MDNTO)

FOR CO-CRYSTALLIZATION SCREEN

Kelley C. Caflin
Peggy Sanchez

November 2015

U.S. ARMY ARMAMENT RESEARCH, DEVELOPMENT AND

ENGINEERING CENTER

list 111

Munitions Engineering Technology Center

Picatinny Arsenal, New Jersey

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1. REPORT DATE (DD-MM-YYYY) 2. REPORT TYPE

November 2015 Final

3. DATES COVERED ( From - To)

Jan. 2014 through Sept. 2014

4. TITLE AND SUBTITLE

SOLUBILITY REPORT OF 1-METHYL-3,5-DINITRO-1 H- 1,2,4-
TRIAZOLE (MDNT) AND 2-METHYL-4,5-DINITRO-2A/-1,2,3-
TRIAZOLE 1-OXIDE (MDNTO) FOR CO-CRYSTALLIZATION
SCREEN

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHORS

Kelley C. Caflin and Peggy Sanchez

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

U.S. ArmyARDEC, METC

Energetics, Warheads & Manufacturing Technology Directorate
(RDAR-MEE-W)

Picatinny Arsenal, NJ 07806-5000

8. PERFORMING ORGANIZATION

REPORT NUMBER

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

U.S. ArmyARDEC, ESIC

Knowledge & Process Management (RDAR-EIK)

Picatinny Arsenal, NJ 07806-5000

10. SPONSOR/MONITOR’S ACRONYM(S)

11. SPONSOR/MONITOR’S REPORT
NUMBER(S)

Technical Report ARMET-TR-15028

12. DISTRIBUTION/AVAILABILITY STATEMENT

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13. SUPPLEMENTARY NOTES

14. ABSTRACT

Solubilities of 1-methyl-3,5-dinitro-1A/-1,2,4-triazole (MDNT) and 2-methyl-4,5-dinitro-2A/-1,2,3-triazole 1-
oxide (MDNTO) in a range of organic solvents were studied in an Avantium Crystal16™ parallel crystallizer in
preparation for co-crystallization screening of these energetic melt-cast materials. Solubility curves were
constructed by evaluating the turbidity of solutions through a range of temperatures. Concentration versus
temperature plots showed models with R 2 values ranging from 0.8464 to 0.9947. Most model fits were linear in
nature with the exception of MDNT in methanol which exhibits two distinct regions of solubility, first linear to a
temperature of approximately 42°C, followed by an exponential region from 40° to 60°C. Nuclear magnetic
resonance studies were conducted in an effort to determine the cause of this change. Unfortunately, variable
temperature studies of both and 13 C of MDNT in deuterated methanol yielded no evidence of a change in
structure at elevated temperatures. Further research is required to determine the cause of the distinct change
in MDNT solubility in methanol. The resulting solubility data was also converted to van’t Hoff plots which can
be used to interpolate or extrapolate the component solubilities at alternate temperatures.

15. SUBJECT TERMS

1-methyl-3,5-dinitro-1 H- 1,2,4-triazole (MDN"

f) 2-methyl-4,5-dinitro-2W1,2,3-triazole 1-oxide (MDNTO) solubility

16. SECURITY CLASSIFICATION OF:

17. LIMITATION OF
ABSTRACT

SAR

18. NUMBER
OF

PAGES

21

19a. NAME OF RESPONSIBLE PERSON
K.C. Caflin

a. REPORT b. ABSTRACT c. THIS PAGE

u u u

19b. TELEPHONE NUMBER (Include area

code) (973) 724-2657

Standard Form 298 (Rev. 8/98)

Prescribed by ANSI Std. Z39.18

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CONTENTS

Page

Introduction 1

Experimental Procedures 2

Materials 2

Solubility 2

Nuclear Magnetic Resonance 8

Results and Discussion 9

Conclusions 12

References 13

Distribution List 15

FIGURES

1 Molecular structures of MDNT and MDNTO 2

2 Experimental solubility curves for MDNT and MDNTO in acetone 3

3 Experimental solubility curves for MDNT and MDNTO in isopropanol 4

4 Experimental solubility curves for MDNT and MDNTO in ethanol 5

5 Experimental solubility curves for MDNT and MDNTO in n-butanol 6

6 Experimental solubility curves for MDNT and MDNTO in ethyl acetate 7

7 Experimental solubility curves for MDNT and MDNTO in methanol 8

8 The solubility curves of MDNT represented by trendline equations in the temperature range

examined for each selected solvent 10

9 The solubility curves of MDNTO represented by trendline equations in the temperature range

examined for each selected solvent 11

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PREFACE

The purpose of this research was to determine the solubility of 1 -methyl-3,5-dinitro-1 HA ,2,4-
triazole (MDNT) and 2-methyl-4,5-dinitro-2A/-1,2,3-triazole 1-oxide (MDNTO) in various solvents for
eventual co-crystallization. Dr. Reddy Damavarapu is to be thanked for guidance and materials.

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INTRODUCTION

Co-crystallization is a technique that has been widely used in the pharmaceutical industry as
a method to deliver co-drugs or improve physicochemical or pharmaceutical properties (ref. 1). New
molecular architectures synthesized by assembling organized co-formers through noncovalent
forces in novel crystalline lattices allow for tailorable properties of co-crystalline compounds such as
melting point and solubility. These properties are unique from those exhibited by either co-former or
a discrete mixture of individual co-formers. Recent research and development of new co¬
crystallization techniques has brought attention to the benefits of co-crystallization in the area of
energetic materials (refs. 2 and 3).

Rather than synthesizing new energetic materials by introduction of functional groups on
oxidizable backbones or heteroatomic ring systems, co-crystallizations allows for combinatorial
effects of existing compounds through simplified synthetic techniques such as solution
crystallization, grinding, and melting. Successes of energetic co-crystallizations have been reported
through the synthesis of a HMX/AP co-crystal that was not water soluble by Levinthal (ref. 4) and
less sensitive 2CL-20:HMX co-crystals reported by Matzger(ref. 5).

Essential to the formation and property predictions of energetic co-crystals is an
understanding of the intermolecular forces between co-formers and how these interactions affect
explosive properties. As an example, the extensive inter- and intra-molecular hydrogen bonding in a
2,4,6 triamino-1,3,5-trinitrobenzene crystal lattice is attributed to excellent thermal stability, reduced
sensitivity, and low solubility in all solvents (ref. 6). The potential for hydrogen bonding is vast in the
area of energetic materials from the prevalence of amino and nitro functional groups, and it is
predicted that the extension of additional intermolecular hydrogen bonding in co-crystal lattices will
have a similar effect on energetic co-crystalline materials. Additional noncovalent forces that can be
attributed to the formation of co-crystals are n-n stacking and van der Waals, both of which are
capable of contributing to greater crystal packing and density that lead to higher predicted
performance.

Proper selection of co-formers is essential not only for the synthesis of the resulting co¬
crystal due to noncovalent bonding forces but also for prediction of explosive performance.

Properties such as the type and extent of noncovalent bonds formed in the co-crystal, molecular
composition of individual co-formers and their ratios in the co-crystal, co-former and co-crystal
polymorphs, sensitivity and performance of co-formers amongst others all have the capability of
affecting explosive performance of the co-crystal. It is for these reasons that 1-methyl-3,5-dinitro-
1A/-1,2,4-triazole (MDNT) and 2-methyl-4,5-dinitro-2A/-1,2,3-triazole 1-oxide (MDNTO) were selected
for study as co-crystal co-formers. Both compounds are high energy Composition B and RDX
replacements, melt-castable materials with melting points of 98° and 130°Cfor MDNT and MDNTO
respectively, and exhibit increased insensitivity with respect to RDX. Of importance is that they are
not nitramine materials that have mainly been studied in the past for energetic co-crystallization,
possess no known polymorphs, and their corresponding molecular structures complement each
other well with regards to potential n-n stacking and hydrogen bonding. Additionally beneficial is the
wide range of solubility expressed by each compound in organic solvents that make them ideal
candidates for solvent-based co-crystallization methods (fig. 1).

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1

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o

N

\

N + -O'

O

MDNT

l-methyl-3,5-dinitro-l//-l,2,4-tri azole

MDNTO

2-methyl-4,5-dinitro-2/V-1,2,3-triazole 1 -oxide

Figure 1

Molecular structures of MDNT and MDNTO

In order to prepare energetic co-crystals, detailed screening techniques are necessary,
especially for solution preparation methods that are generally done from saturated solutions of the
pure components. For this reason, solubility curves and van’t Hoff plots of the two selected co¬
formers were experimentally determined. These results will be used to predict ideal solvents, co¬
former ratios, and temperatures for co-crystal formation.

EXPERIMENTAL PROCEDURES

Materials

The MDNT (ref. 7) and MDNTO (ref. 8) were synthesized at the U.S. Army Armament
Research, Development and Engineering Center, Picatinny Arsenal, NJ, and determined pure by
both nuclear magnetic resonance (NMR) and melting point. Solvents used for solubility experiments
were purchased from commercial sources and used without further purification. Reagent grade
acetone and methanol were purchased from Pharmco-AAPER, Brookfield, CT. Ethyl Acetate
(99.99% extra dry AcroSeal from Acros Organics, Belguim) was purchased from Fisher Scientific,
Pittsburgh, PA. Methanol (anhydrous, 99.8%), 1-butanol, isopropanol and ethanol (200 proof) were
purchased from Sigma Aldrich, St. Louis, MO. Methanol-d 4 with +0.05% V/V TMS was purchased
from Cambridge Isotope Laboratories, Inc., Tewksury, MA

Solubility

Solubility determinations of the pure components were determined on an Avantium
Crystal16™ and were analyzed using the CrystalClear software package. Solvents investigated were
acetone, ethyl acetate, methanol, ethanol, isopropanol, and n-butanol. In each experiment, the
solute was weighed into a small, clear, and colorless high performance liquid chromatography
(HPLC) type vial equipped with a magnetic stir bar. Solvent was added and exact concentration
recorded. The vials were placed into the Avantium Crystal16™, and temperature was cycled three
times from 20° to 5°C below the boiling point of solvent with 90 min equilibration periods between
heating and cooling. Ramp rates were 0.5° and -0.3°C/min.

The solubility of each vial solution was determined by identifying clear point temperatures,
defined as the temperature at which the turbidity of the solution decreases upon heating and the
solution becomes transparent. Graphing the clear point temperatures versus the concentration of the

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solution yields a solubility curve and associated equation. Solubility data of the individual materials
were then fitted to the van’t Hoff equation as shown in figures 2 through 7.

Median standard deviation (MStdDev) was reported for error. This represents the median of clear
point standard deviations in temperature at each concentration in which two or more measurements
were made.

0.003 0.0031 0.0032 0.0033 0.0034

Note: The MDNT has a MStdDev of 0.28 and a range of 0.11° to 0.87°C. The MDNTO has a MStdDev of 0.25 and a
range of 0.17° to 0.82°C.

(a)

The solubility curve of
MDNT (*) and MDNTO (0)
in acetone

(b)

van’t Hoff solubility plot of
MDNT (*) and MDNTO (0)
in acetone

Figure 2

Experimental solubility curves for MDNT and MDNTO in acetone

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0.0029 0.003 0.0031 0.0032 0.0033

Note: The MDNT has a MStdDev of 0.32 and a range of 0.15° to 0.85°C. The MDNTO has a MStdDev of 1.87 and a

range of 1.51 0 to 3.61 °C.

(a)

The solubility curve
of MDNT (x) and MDNTO ( 0 )
in isopropanol

(b)

van’t Hoff solubility plot
of MDNT (x) and MDNTO ( 0 )
in isopropanol

Figure 3

Experimental solubility curves for MDNT and MDNTO in isopropanol

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Contentration (mg/mL)

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0.0028 0.003 0.0032 0.0034

Note: The MDNTO has a MStdDev of 2.08 and a range of 1.82° to 2.50°C. No repeat measurements were present

MDNT.

(a)

The solubility curve of
MDNT and MDNTO in ethanol

(b)

van’t Hoff solubility plot
of MDNT and MDNTO in ethanol

Figure 4

Experimental solubility curves for MDNT and MDNTO in ethanol

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0.0029 0.003 0.0031 0.0032

Note: The MDNTO has a MStdDev of 0.14 and a range of 0.07° to 1.47°C. No repeat measurements were present

MDNT.

(a)

The solubility curve
of MDNT (x) and MDNTO ( 0 )
in n-butanol

(b)

van’t Hoff solubility plot
of MDNT (x) and MDNTO ( 0 )
in n-butanol

Figure 5

Experimental solubility curves for MDNT and MDNTO in n-butanol

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Concentration (mg/mL)

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0.0028 0.003 0.0032 0.0034

Note: The MDNT has a MStdDev of 0.29 and a range of 0.15° to 0.76°C. The MDNTO has a MStdDev of 0.21 and a

range of 0.06° to 0.4 0°C.

(a)

The solubility curve
of MDNT (x) and MDNTO ( 0 )
in ethyl acetate

(b)

van’t Hoff solubility plot
of MDNT (x) and MDNTO ( 0 )
in ethyl acetate

Figure 6

Experimental solubility curves for MDNT and MDNTO in ethyl acetate

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Note: The MDNT is broken down into two temperature ranges of 24.6° to 41,6°C and 44.1 ° to 54.1 °C correlating to the
two different trendlines. The MDNT has a MStdDev of 0.38 and a range of 0.25° to 1,77°C. The MDNTO has a
MStdDev of 2.81 and a range of 1.63° to 4.88°C.

(a) (b)

The solubility curve van’t Hoff solubility plot

of MDNT (x) and MDNTO ( 0 ) of MDNT (x) and MDNTO ( 0 )

in methanol in methanol

Figure 7

Experimental solubility curves for MDNT and MDNTO in methanol

Nuclear Magnetic Resonance

A Bruker 400 MHz NMR equipped with a PA BBO 400SB BBF-H-D-05 Z probe was used to
conduct variable temperature measurements of MDNT in deuterated methanol. Proton spectra were
collected with a conventional pulse program (zg30) with a 10.69 ps pulse, 5.12 sec acquisition time
and 1 sec pulse delay. Carbon-13 spectra were collected with a pulse program (zgpg30) with a
10.00 ps pulse, 3 sec acquisition time with decoupling and 2 sec pulse delay.

Temperature of the probe was precisely controlled, and the evaluated temperatures were set
and allowed to equilibrate before spectra were acquired. The NMR was tuned, matched, and
shimmed at each temperature to obtain quality data. Proton data was collected at 5°C intervals from
25° to 60°C. Carbon data was collected at 22° and 50°C. Carbon data was limited due to extended
collection times at low concentrations.

The ^-NMR analysis sample preparation: The NMR sample was prepared by adding MDNT
to an NMR tube with approximately 0.75 mL of deuterated methanol at ambient temperature. The
NMR tube was inverted until a uniform solution was achieved. A blank sample of deuterated
methanol was also prepared for direct comparison of solvent peak movement due to variable
temperature.

The 22°C 13 C-NMR analysis sample preparation: 0.75 mL deuterated methanol was added
to a small HPLC style vial at ambient conditions, MDNT was added until just below the saturation
point. The solution was then transferred to a standard 5-mm NMR tube for analysis.

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50°C 13 C-NMR analysis sample preparation: MDNT (~200 mg) was added to 0.75 mL
deuterated methanol in a vial and was subsequently heated to 60°C until all MDNT was dissolved.
The solution was then transferred to a standard 5-mm NMR tube for analysis. All MDNT remained in
solution.

RESULTS AND DISCUSSION

To interpret the data as an ideal system for better extrapolation or interpolation values, a
van’t Hoff plot was calculated from each solubility curve

lnx =

AH (1 1\

~R \T ~ TJ

( 1 )

where x is the component mole fraction, AH is the dissolution enthalpy, To (K) is a set-point
temperature, and T (K) is the saturation temperature of the mole fraction x (ref. 1). As shown in
figures 2 through 6, solubilities of MDNT and MDNTO in acetone, ethyl acetate, ethanol,
isopropanol, and n-butanol are well correlated by the van’t Hoff equation. Although MDNTO
solubility exhibits a linear van’t Hoff plot in methanol, MDNT shows two distinct linear regions upon
temperature increase indicating possible solvation, tautermizeration, or polymorphism. To better
understand the chemical changes occurring in the MDNT/methanol solute solvent interactions, a
temperature dependent NMR study was performed.

Figure 8 is a comparison of the solubilities of MDNT and MDNTO in the various organic
solvents investigated. These plots are based on the model trendlines that were constructed from the
experimental data. It can be seen that MDNT is highly soluble in both acetone and ethyl acetate and
exhibits lower solubility levels in the remaining solvents (fig. 8) (table 1). It can also be noted that the
solubility of DNMT is consistently higher in each solvent than that of DNMTO (fig. 9) (table 2).

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MDNT Solubility Comparison in Selected Solvents

Figure 8

The solubility curves of MDNT represented by trendline equations in the temperature range

examined for each selected solvent

Table 1

Predicted solubility of MDNT (mg/mL) from trendline equations in selected solvents at 30°C and the

highest temperature evaluated in the Crystal16

Solubilil

ty of MDNT (mg/mL)

Solvent

30°C

Maximum temperature (X°C)

n-Butanol

0

74.174 (75)

Isopropanol

0

84.06 (75)

Ethanol

26.817

183.9885 (75)

Methanol

48.219

503.1467 (60)

Ethyl acetate

308.06

1609.06 (70)

Acetone

1321.06

2219.76 (50)

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MDNTO Solubility Comparison in Selected Solvents

cm

E

£

OJ

u

£

O

U

Methanol

Ethanol

Isopropanol

n-Butanol

Acetone

Ethyl Acetate

-100

40 50 60

Temperature (°C)

Figure 9

The solubility curves of MDNTO represented by trendline equations in the temperature range

examined for each selected solvent

Table 2

Predicted solubility of MDMT (mg/mL) from trendline equations in selected solvents at 30°C and the

highest temperature evaluated in the Crystal16

Solul

bility of MDNTO (mg/mL)

Solvent

30°C

Maximum temperature (X°C)

n-Butanol

0

24.0775 (75)

Isopropanol

0

27.4745 (75)

Ethanol

10.62

41.2698 (75)

Methanol

29.327

83.768 (60)

Ethyl acetate

132.066

379.494 (70)

Acetone

454.21

711.73 (50)

The experimental solubility curves for MDNT and MDNTO in each of the investigated
solvents are shown in figures 2 through 7 with associated predictive trend equations and R 2 values.
Saturation temperatures or clear points of the co-formers in selected solvent were easily discernible
by sharp transitions to near 0% turbidity. As the method developed to include three temperature
cycles, multiple data points are associated with each clear point for each concentration of solute
examined. The median standard deviation of clear point temperature with this technique is 0.46°C
with a maximum of 4.88°C and minimum of 0.06°C. Data points were excluded if the clear point was
not definitive. This is typically associated with a significant amount of noise due to the ripening of
large solute crystals upon cooling that disrupt turbidity measurements. In some cases, fewer data
points are available at lower temperatures for those concentrations at which the solute did not
crystallize from solution upon cooling to the lower temperature limit of 20°C. Under these
circumstances, only one clear point from the three data points associated with the temperature
cycles is available as the solute remained in solution for the duration of the experiment. All of the
solubility curves are represented by the van’t Hoff equation for better extrapolation.

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The MDNT in methanol produced the only solubility curve that did not correlate well to any
one trendline. The solubility of MDNT in methanol increased steadily in a linear fashion until
approximately 42°C where it began to increase at an exponential rate. It was initially postulated that
the difference could be due to small amounts of residual water in the solvent. This theory was
negated when anhydrous methanol was used and data produced with stock and anhydrous solvent
showed identical results within experimental error. This anomaly is also expressed in the van’t Hoff
plot where two linear ranges are apparent. The NMR studies were then performed to determine the
presence of possible chemical or solvate changes with increased temperature.

Proton data collected at variable temperatures were examined for changes in the methyl
group of the MDNT molecule. The singlet methyl group peak remained unchanged at ~4.36 ppm
throughout the range of the experiment from 25° to 60°C indicating no change with respect to the
formation of tautomers or solvates. The deuterated alcohol methanol signal shifted down with
temperature from 4.80 ppm at 25°C to 4.42 ppm at 60°C while the signal from the methyl group
remained unchanged at 3.31 ppm. Solvent signal movement was confirmed with repeated
measurements of a blank solvent sample.

Carbon-13 NMR performed at room temperature was complicated by the dilute nature of the
sample; although MDNT was saturated in the solvent, the concentration of the sample was low. Due
to the low concentration, 10240 scans were required to give ample signal to noise for detection of the
MDNT ring carbons that were located at 158.69 and 152.52 ppm. The methyl carbon and deuterated
methanol solvent peak were located at 42.23 and 49.04 ppm respectively. Elevated temperature
carbon was run at 50°C which allowed for the concentration of the MDNT to dramatically increase,
allowing 1024 scans to be enough for needed resolution of the ring carbons. Ring carbons were
located at 156.87 and 150.55 ppm, while the methyl carbon and deuterated methanol solvent peak
were located at 40.15 and 47.25 ppm respectively. Minor changes to the chemical shift between
samples were concluded to be a temperature effect as the deuterated methanol peaks shifted an
equal amount to the ring and methyl MDNT carbons. Unfortunately, variable temperature studies,
both and 13 C, of MDNT in deuterated methanol yielded no evidence of a change in structure at
elevated temperatures. Further research is required to determine the cause of the distinct change in
MDNT solubility in methanol.

CONCLUSIONS

Solubility curves of 1-Methyl-3,5-Dinitro-1A/-1,2,4-Triazole (MDNT) and 2-methyl-4,5-dinitro-
2A/-1,2,3-triazole 1-oxide (MDNTO) have been provided in multiple organic solvents using the
Avantium Crystal16™. This technique showed good precision of measurement yielding median
standard deviation of clear point temperature of 0.46°C. Most model fits were linear and exhibited a
predicted single smooth trend line. The MDNT in methanol exhibits a different behavior in which two
distinct regions of solubility were observed. Effort was made to determine the cause of the change
using and 13 C variable temperature studies of MDNT in deuterated methanol. Unfortunately, the
nuclear magnetic resonance data produced no explanation for the solubility change; research is
ongoing for this matter. Solubility data collected was converted using the van’t Hoff equation for
better extrapolation of solubility values. This work will be the basis for additional work with MDNT
and MDNTO including co-crystal screening for the potential formation of MDNT/MDNTO energetic
co-crystals.

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REFERENCES

1 ter Horst, J.H., Deij, M.A., Cains, P.W., “Discovering New Co-Crystals,” Crystal Growth & Design,
Vol. 9, No. 3, pp. 1531-1537, 2009.

2 Landenberger, K., Matzger, A., “Cocrystal Engineering of a Prototype Energetic Material:
Supramolecular Chemistry of a 2,4,6-Trinitrotoluene,” Crystal Growth & Design, Vol. 10, 5341-
5347,2010.

3 Zhang, C., Cao, Y., Li, H., Zhou, Y., Zhou, J., Geo, T., Zhang, H., Jiang, G., “Toward Low-
Sensitive and High-Energetic Cocrystal 1: Evaluation of the Power and the Safety of Observed
Energetic Cocrystals,” CrystEngComm, 15, 4003-4014, 2013.

4 Levinthal, M.L., “Propellant Made With Cocrystals of Cyclotetramethylenetranitramine and
Ammonium Perchlorate,” U.S. Patent 4086110.

5 Bolton, O., Smike, L., Pagoria, P., Matzger, A., “High Power Explosive with Good Sensitivity: A
2:1 Cocrystal of CL-20: HMX,” Crystal Growth & Design, Vol. 12, pp. 4311-4314, 2012.

6 Agrawal, P., “High Energy Materials: Propellants, Explosives and Pyrotechnics,” Wiley-VCH,
Weinheim, 85, 2010.

7 Katritzky, A., Vakulenko, A., Sivapackiam, J., Draghici, B., Damavarapu, R., “Synthesis of
Dinitro-Substituted Furans, Thiophenes, and Azoles,” Synthesis, 5, 699-706, 2008.

8 Begtrup, M., Nytoft, H.P., “2-Alkyl-1,2,3-Triazole-1-Oxides: Preparation and Use in the Synthesis
of 2-Alkyltriazoles,” Acta Chemica Scandinavica B40 , 262 to 269, 1986.

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DISTRIBUTION LIST

U.S. ArmyARDEC
ATTN: RDAR-EIK

RDAR-MEE-W, K.C. Caflin
P. Sanchez

Picatinny Arsenal, NJ 07806-5000

Defense Technical Information Center (DTIC)
ATTN: Accessions Division
8725 John J. Kingman Road, Ste. 0944
Fort Belvoir, VA 22060-6218

GIDEP Operations Center
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REVIEW ANO APPROVAL OF ARDGC TECHNICAL REPORTS
Solubility Report ofDNMT and DNMTO for Co-Ciystidluatioo Screen

TNe

MhrCiflin

AidhorfProtedl

Eng near

Data received by LRED

Report number (to be imQrml by LRED)

X2B67

Extension

30?»

Building

RDAR-MEEW_

Author'sAPn^eci Engl «»r» Off**
(DMston, Laboratory. Symbol)

PARTI, that be eigned before the report can be edited.

a.

The draft oopy of this report nee been
for editing

reviewed tar technical accuracy end fc approved

Uee Distribution Statement \.A_, B C D E F_or X_lor the reason

checked on the conttrajation of hbtoA Hm*n: - - -

1 If Ststamem A Is selected, the report *■ be rateeeed to the NelkMi Technical
intanrabon Service (NT)8) tor sale to the general public. Only unotaoeMad reports
whose distribution Is rat limited or controlled h eny way ere -nltiaarl to NTtS.

2. If Statement B. C.D.E.F. or X Is satscted, toe report will be reieaaed to the Detonee
Technical IntormaHon Center (DT1C) which wiB Omit cflstributicn according to the
conditions indicated in the stetement.

c. The distribution let far INs report hes been rev i ewed tar aocuracy end com p la ten see

Steven M. Nicolich

OvMon Chief

£

Intedgenoe end

Thli draft oopy of We report hes been re newed tor aenaitive metanel and approved by the
nd Technology Protection Office, BWg 93.1 - Floor. Room 120 (Vffiilt).

Andrew Pskowski ;

riSa^-cis

(Date)

PANT2. To bo rtgned either when draft report to submitted or
TWe report Is approved tar pubkestton. ,

review of reproduction copy.

m

n

Steven M. Nicolich

fiivWofl Chief