Zeitgeist
January 3rd, 2005, 10:40 AM
I wasn't sure what section is best for this.
2,3-dimethyl-2,3-dinitrobutane. Used as a marking/tagging agent in explosives such as C-4, at a level of 0.1 to 0.5%.
Now, what if someone added the material to a bomb, constucted from any old explosive you choose? Would the use of a high-grade military RDX-based plastique such as C4 or Semtex be suspected, turning investigation more towards those with access to such materials, rather than an individual with synthesised RDX, AN or whatever your tastes run to?
I found a synth, i don't quite follow where the Br comes from though,
The following low-cost one-pound process developed by ARDEC may be used to scale-up the synthesis to the 100 pound scale to yield low cost DMNB with a purity of at leasst 98.00 weight percent. A) Preparation of 2-Bromo-2-nitropropane = 2-Nitropropane (commercial, 97% 2-NP; impurities; nitroethane and 1-nitropropane; 450.0g, 5.0 moles) was added in 30 minutes to a stirred solution of sodium hydroxide (220.0g, 5.5 moles) in water 2.5 liters) at 0-5 degrees C. The reaction solution was stored at 0-5 degrees C for 30 minutes and then brought to room temperature. After 30 minutes the lower layer, 2-bromo-2-nitropropane (829.9g, 98.8% yield), was separated. The crude 2-bromo-2-nitropropane contains small amounts of bromonitroethanes and bromo-1-nitropropanes but is quite satisfactory for preparation of 2,3-dimethyl-2,3-dinitrobutane without any purification. B) Preparation of 2,3 dimethyl-2,3-dinitrobutane from Sodium 2-propanenitronate and 2-Bromo-2-nitropropane = A mixture of 2-nitropropane (90.0g, 1.0 mole) and sodium hydroxide (56.0g, 1.4 mole) in methanol (500 ml) was stirred at room temperature for 30 minutes and then brought to reflux. 2-Bromo-2-nitropropane (168.0g, 1.0 mole) was added in 15 minutes. The reaction mixture was refluxed 24 hours and cooled to room temperature. The solid present, 2,3-dimethyl-2,3- dinitrobutane and sodium bromide, was filtered. Methanol and water were removed from the filtrate by reduced pressure distillation to yield a solid concentrate. The reaction solids were combined, stirred with cold water (250 ml), and filtered. The filtered solid was rinsed with cold methanol (150 ml) to give white 2,3-dimethyl- 2,3-dinitrobutane (140.6g, 79.0% yield), mp 209-210 degrees C. Evaporation of the methanol washings gave a yellow solid which was washed with water, filtered, and recrystallized to yield additional 2,3-dimethyl-2,3-dinitrobutane (2.70g, 2.5% yield) mp 202-210 degrees C. The total yield of white 2,3-dimethyl-2,3-dinitrobutane is 80.5%. When the above reaction is conducted on a 5 mole scale, addition of 2-bromo-2-nitropropane (840g, 5 moles) to 2-nitropropane (450g, 5 moles) and sodium hydroxide (280g, 7.0 moles) in refluxing methanol (2.5L) alleviates much of the problem in agitation. It is not yet known what volumes of solvent will be needed for effective agitation and satisfactory efficiencies on larger scale reactions. Secondly, on the larger scale reactions, washing the crude 2,3-dimethyl-2,3-dinitrobutane on a filter pad or plate with cold methanol is not satisfactory for removing all of the colored by-products from the desired material. The methanol passes over the solid product too quickly to wash out all of the surface impurities in the 2,3-dimethyl-2,3-dinitrobutane. Stirring the colored 2,3-dimetyl-2,3-dinitrobutane with cold ethanol in the initial reactor equipment improves the product greatly and lowers the overall yield to about 75%.
2,3-dimethyl-2,3-dinitrobutane. Used as a marking/tagging agent in explosives such as C-4, at a level of 0.1 to 0.5%.
Now, what if someone added the material to a bomb, constucted from any old explosive you choose? Would the use of a high-grade military RDX-based plastique such as C4 or Semtex be suspected, turning investigation more towards those with access to such materials, rather than an individual with synthesised RDX, AN or whatever your tastes run to?
I found a synth, i don't quite follow where the Br comes from though,
The following low-cost one-pound process developed by ARDEC may be used to scale-up the synthesis to the 100 pound scale to yield low cost DMNB with a purity of at leasst 98.00 weight percent. A) Preparation of 2-Bromo-2-nitropropane = 2-Nitropropane (commercial, 97% 2-NP; impurities; nitroethane and 1-nitropropane; 450.0g, 5.0 moles) was added in 30 minutes to a stirred solution of sodium hydroxide (220.0g, 5.5 moles) in water 2.5 liters) at 0-5 degrees C. The reaction solution was stored at 0-5 degrees C for 30 minutes and then brought to room temperature. After 30 minutes the lower layer, 2-bromo-2-nitropropane (829.9g, 98.8% yield), was separated. The crude 2-bromo-2-nitropropane contains small amounts of bromonitroethanes and bromo-1-nitropropanes but is quite satisfactory for preparation of 2,3-dimethyl-2,3-dinitrobutane without any purification. B) Preparation of 2,3 dimethyl-2,3-dinitrobutane from Sodium 2-propanenitronate and 2-Bromo-2-nitropropane = A mixture of 2-nitropropane (90.0g, 1.0 mole) and sodium hydroxide (56.0g, 1.4 mole) in methanol (500 ml) was stirred at room temperature for 30 minutes and then brought to reflux. 2-Bromo-2-nitropropane (168.0g, 1.0 mole) was added in 15 minutes. The reaction mixture was refluxed 24 hours and cooled to room temperature. The solid present, 2,3-dimethyl-2,3- dinitrobutane and sodium bromide, was filtered. Methanol and water were removed from the filtrate by reduced pressure distillation to yield a solid concentrate. The reaction solids were combined, stirred with cold water (250 ml), and filtered. The filtered solid was rinsed with cold methanol (150 ml) to give white 2,3-dimethyl- 2,3-dinitrobutane (140.6g, 79.0% yield), mp 209-210 degrees C. Evaporation of the methanol washings gave a yellow solid which was washed with water, filtered, and recrystallized to yield additional 2,3-dimethyl-2,3-dinitrobutane (2.70g, 2.5% yield) mp 202-210 degrees C. The total yield of white 2,3-dimethyl-2,3-dinitrobutane is 80.5%. When the above reaction is conducted on a 5 mole scale, addition of 2-bromo-2-nitropropane (840g, 5 moles) to 2-nitropropane (450g, 5 moles) and sodium hydroxide (280g, 7.0 moles) in refluxing methanol (2.5L) alleviates much of the problem in agitation. It is not yet known what volumes of solvent will be needed for effective agitation and satisfactory efficiencies on larger scale reactions. Secondly, on the larger scale reactions, washing the crude 2,3-dimethyl-2,3-dinitrobutane on a filter pad or plate with cold methanol is not satisfactory for removing all of the colored by-products from the desired material. The methanol passes over the solid product too quickly to wash out all of the surface impurities in the 2,3-dimethyl-2,3-dinitrobutane. Stirring the colored 2,3-dimetyl-2,3-dinitrobutane with cold ethanol in the initial reactor equipment improves the product greatly and lowers the overall yield to about 75%.