2.6 Synthesis of Compound 6: trans-1.2-Dinitrocyclopropane (DNCP).
Wade and co-workers' procedure<sup>9</sup> for the synthesis of trans-1,2-dinitrocyclopropane
(compound 6) was substantially improved for scale-up purposes. The
original and the improved procedures employ 1,3-dinitropropane in DMSO solution.
The original procedure used dimethylsodium as the base, and reaction temperature
and time were crucial. The original procedure is strongly exothermic and would not be
readily amenable to scale up.
11
The improved procedure involves treatment with 10 molar equivalents of
sodium acetate* as a mild base and 3 molar equivalents of iodine. Ring closure takes
place in approximately 2 hr. In our best run on a 100 mg scale, a 43% crude yield of
compound 6, which could be readily recrystallized to yield pure compound 6 (not
optimized, small scale), was obtained.
When scaled up, the improved procedure gave pure product by
recrystallization but provided a lower yield. A solution of 1,3-dinitropropane (2.0 g,
14.9 mmol) in DMSO (50 mL) was added dropwise over 5 min to a cooled solution
containing sodium acetate (12.3 g, 149 mmol) and iodine (11.4 g, 45 mmol) in DMSO
(200 mL). Cooling during the addition was performed so that the temperature did not
rise above 30 °C. In one run where the reaction temperature was not controlled and
rose to near 50 °C, a side product tentatively identified as 5-nitroisoxazole was formed
in significant quantity. The resulting solution was poured into ice-cold brine (2 L).
Extraction with ethoxylacetate (three 100-mL portions) followed by washing with brine
(three 100-mL portions), drying over anhydrous Na2S04, and concentration gave 1.86 g
of crude product. The product was recrystallized from CCl4-hexanes to give 223 mg of
pure compound 6 and a second crop of 83 mg of fairly pure compound 6. Chromatography
of the mother liquor provided more product, which was combined with the
second crop and recrystallized to yield 200 mg of pure compound 6 (423 mg total, 21%
yield). The procedure was repeated two times to prepare a total of 1.2 g of com-'
pound 6.
3. DETONATION EXPERIMENTS
Detonation studies were conducted on compounds 1-6 to determine which
compounds would be best to use in follow-through devices. Most of the detonation
studies involved using 25 mL of a nitromethane solution of the compound being tested
and employing morpholine as a sensitizer. The solution was placed in a sample tube
mounted on a plastic block (blast observation device). Polypropylene and high-density
polyethylene blocks were used.
The sample tube was fitted at the top with a blast cap and explosive
booster pellet placed touching the solution, and the device was detonated remotely
(Figure 1). The observation block typically developed a crater from the ensuing blast.
The size of the crater was measured by filling it with water and determining the volume
of water. The results obtained are presented in Tables 2-6. A number of experiments
involving detonation of sensitized nitromethane, not admixed with test compounds,
were performed to develop reference standards. The results of the reference
detonations are listed in Table 7. |
Why monopropellant with impulse anywhere near cryogenic O2/H2 wouldnt be extremely totaly detonateable? Solid fuels arent so bad as impulse. If a
liquid system doesnt use turbopomps and the engine is pressure fed there wouldnt be significant advantage over solid fuels. So cheap stuff in to
space... I think for anything serious a two component fuel is needed. At least dioxide/kerosine or better. The rest I think is more about efficient
mass production technology. 
Shouldn't you old guys be moving important
businesses instead of mixing *** and watch what will happen? 
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