Oxidation and nitration of C N bonds 15available ketone groups to nitro andgem-dinitroaliphatic functionality is usually via the oxime
and this is an important route used in energetic materials synthesis.
1.6.1.1 Scholl reaction^122
fuming HNO 3 ,
oleum
12 %
49
50NO 2 NO 2NO 2 NO 2CH 3 CH 3
H 3 C CH 3HON NOH
CC CCFigure 1.19One route togem-dinitroalkanes involves the tandem nitration–oxidation of oximes.^122 The
nitration of dimethylglyoxime (49) with anhydrous mixed acid is reported to give 2,2,3,3-
tetranitrobutane (50) in 12 % yield.^39 However, ammonium nitrate and nitric acid in methylene
chloride is a more commonly used reagent, but the product, usually a pseudonitrole, needs
treatment with hydrogen peroxide to yield thegem-dinitro compound. The nitric acid used in
these reactions often contains 12–24 % dissolved dinitrogen tetroxide (‘red fuming nitric acid’)
and so the reaction has similarities with the Ponzio reaction (Section 1.6.1.2). Some energetic
materials recently synthesized with this reagent are illustrated in Table 1.4 (also see Chapter 2).
O 2 NO 2 NNO 2 O 2 NO 2 NO 2 NO 2 NNO 2NO 2NO 2NO 2
NO 2NO 2NO 2NO 2NO 2NO 2NO 2
NO 2NO 2NO 2NO 2NO 2NO 2NO 2NO 2NOHNOHHONNOHHON- 98 % red HNO 3 ,
NH 4 NO 3 , CH 2 Cl 2 ,
reflux - 30 % H 2 O 2 (aq)
reflux
31 % (2 steps) - 98 % red HNO 3 ,
urea, NH 4 NO 3 ,
CH 2 Cl 2 , reflux
2. 30 % H 2 O 2 (aq)
reflux
19 % (2 steps)
98 % HNO 3 , urea,
CH 2 Cl 2 , NH 4 NO 3
reflux, 29 %- 98 % red HNO 3 ,
CH 2 Cl 2 , urea,
NH 4 NO 3 , reflux
123124125126Table 1.4
Synthesis of energetic polynitropolycycloalkanes via the Scholl reactionOxime Conditions/reagents Product Ref.- 30 % H 2 O 2 (aq)
reflux
52 % (2 steps)