Organic Chemistry of Explosives

222 Synthetic Routes toN-Nitro

H 2 N(CH 2 ) 2 NH 2

H 2 N(CH 2 ) 3 NH 2

C(CH 2 NH 2 ) 4

NN

NOON

NN

O 2 N NO 2

ON NO O 2 NN NNO 2

N

N

N

N

NO 2

O 2 N NO 2

O 2 N

N

N

N

N

N N

NO

NOON

ON

H 2 NCH 2 CH(CH 3 )NH 2 NN

NOON

H 3 C

NN

O 2 N NO 2

H 3 C

Table 5.7

Synthesis of cyclic nitramines using the method of Atkins and Willer (ref. 117)

Entry Substrate

(90)

(95)

(>55) (94)

(85)

(30)

(93) (75)

118 119

117116

113

114 115

88

1

2

3

4

Nitrosamine (% yield) Nitramine (% yield)

(111) from the reaction of linear aliphatic diamines (110) with formaldehyde followed by

trapping the resulting 1,3-diazacycloalkanes with nitrous acid. High yields are reported for the

synthesis of both 5- and 6- membered ring 1,3-dinitrosamines, but yields are much lower for

7-membered ring analogs (Table 5.7). The spirocycle (118) is prepared by treating a mixture

of 2,2-bis(methylamino)-1,3-propanediamine and formaldehyde with nitrous acid.

N

N

N

N

NO 2

NO 2

NO 2

O 2 N

H

H

N

N N

N

H

H

NO 2

120 121

NO 2

O 2 N

NO 2

Figure 5.56

Atkins and Willer^117 ,^118 were unable to oxidize their cyclic 1,3-dinitrosamines to the corre-

sponding 1,3-dinitramines with peroxytrifluoroacetic acid but found that nitrolysis with dini-

trogen pentoxide in nitric acid was more successful (Table 5.7). Willer^118 used the same

methodology to prepare bicyclic 1,3-dinitramines like (120) and (121). It was found necessary

to blow dry nitrogen gas through these reactions in order to remove any dinitrogen tetroxide

formed during the nitrolysis, otherwise the 1,3-dinitramine products were found to contain

1-nitrosamine-3-nitramines as contaminants. 1-Nitrosamine-3-nitramines are found to be the

main products when the cyclic 1,3-dinitrosamines are treated with 100 % nitric acid.