18 Synthetic Routes to AliphaticC-Nitro
NOHHONNOHNO 2NO 2NO 2NO 2O 2 NO 2 NO 2 NNOHHONHHNOHHONHH(CF 3 CO) 2 O, 90 % H 2 O 2 ,
CH 3 CN, NaHCO 3 , urea
70–75 °C, 35 %(CF 3 CO) 2 O, 90 % H 2 O 2 ,
CH 3 CN, Na 2 HPO 4 ,
75 °C, 65 %(CF 3 CO) 2 O, 90 % H 2 O 2 ,
CH 3 CN, NaHCO 3 ,
75 °C, 60 %123141141Table 1.5
Synthesis of energetic polynitropolycycloalkanes via the oxidation of oximes
with peroxytrifluoroacetic acidOxime Conditions/reagents Product Ref.Nielsen^140 used the same chemistry to synthesize both 1,3- and 1,4-dinitrocyclohexanes from
the corresponding dioximes. The peroxytrifluoroacetic acid reagent has been used in reaction
routes to a number of highly energetic polynitropolycycloalkanes as illustrated in Table 1.5
(see also Chapter 2).
Some recent advances have been reported in oxime oxidation, including thein situgeneration
of peroxytrifluoroacetic acid from the reaction of urea hydrogen peroxide complex with TFAA
in acetonitrile at 0◦C.^142 This method gives good yields of nitroalkanes from aldoximes but
fails with ketoximes.
HON NOHNO 2 NO 2H HNO 2HOO(^59) 60 (23 %)
(mixture of isomers)
61 (15 %)
m-CPBA, urea,
CH 3 CN, Na 2 HPO 4
reflux +
Figure 1.26
Peroxyacids are powerful oxidants and so side reactions are to be expected. Ketones are
known to undergo Baeyer–Villiger^143 oxidation to the carboxylic acid ester on treatment with
peroxyacids and so these by-products can be observed if oxime hydrolysis occurs during the
oxidation. Paquette and co-workers^144 observed such a by-product (61) during the oxidation
of the dioxime (59) to the dinitro compound (60) withm-CPBA in hot acetonitrile.
Peroxyacetic acid generatedin situfrom sodium perborate and glacial acetic acid has been
used for oxime to nitro group conversion.^145 Peroxyimidic acid generated from acetonitrile and
hydrogen peroxide has found similar use.^146 An Mo(IV) peroxy complex has been reported
for the oxidation of both ketoximes and aldoximes.^147