236 Synthetic Routes toN-Nitro
O 2 NCH 3 CH 3 CH 3NNNNO 2
2 CH 3 NHNO 2 + 2 CH 2 O + CH 3 NH 2 + 2 H 2 O185Figure 5.81The products obtained from these condensations are predictable for simple mono-functional
substrates; primary amines usually form compounds where two equivalents of primary
nitramine are incorporated into the product (Equation 5.19), whereas simple secondary amines
can only combine with one equivalent of nitramine (Equation 5.20).^157 ,^158 The bis-nitramine
(185) is formed from the reaction of methylamine with two mole equivalents each of methyl-
nitramine and formaldehyde.
NNNNO 2NO 2 NMeMe
186- EtOH, MeNH 2
- EtOAc, CH 2 O
H 2 C
NHNO 2NHNO 2
168Figure 5.82Mannich condensations involving polyamines or polynitramines are more complex, and
in the case of linear dinitramines, leads to very interesting and diverse chemistry, enabling
the synthesis of many cyclic nitramine products. The reaction of methylenedinitramine (168)
with various primary amines in the presence of formaldehyde leads to 1,5-dinitro-1,3,5,7-
tetraazacyclooctanes; the 3,7-dimethyl analogue (186) is isolated when methylamine is used.^158
187, R = Me
188, R = Et
189, R = i-Pr
190, R = NO
191, R = NO 2192O 2 NHN NHNO 2(^174) N
N
O 2 N
O 2 N
NO 2
NO 2
N
N
N
N
N
N
N
R
NO 2
NO 2
Figure 5.83
1,3-Dinitraminopropane (174) reacts with a range of primary amines in the presence of
formaldehyde to yield 1,5-dinitro-1,3,5-triazacyclooctanes like (187) (R=methyl), (188) (R=
ethyl), and (189) (R=iso-propyl).^159 When ammonia is used as the amine component in
these reactions the bicycle (192) is formed.^159 Reaction of the bicycle (192) with nitrous acid
and absolute nitric acid leads to CāN bond cleavage with the formation of (190) and (191),
respectively.^159
Ethylenedinitramine (EDNA) (2) condenses with ammonia in the presence of formaldehyde
to form the triazacycloheptane bicycle (193).^160 The chemistry of the bicycle (193) is very
diverse and is only partly summarized in this discussion.^160