Organic Chemistry of Explosives

Nitroureas 277

Adolph and Cichra^32 used a similar strategy oftert-butyl nitrolysis to synthesize 1,5,5-

trinitro-1,3-oxazine (95) and the bicycle (96).

HN

N

NH

t-Bu

99

89 %

H 2 N

N

NO 2 N

NO 2

HN

N

NH

N

NO 2

NO 2

100

2 eq CH 2 O,

t-BuNH 2 , H 2 O

HNO 3 , Ac 2 O,

NH 4 Cl

98 87 %

NH 2

Figure 6.26

Dagley and co-workers^35 reported the synthesis of 2-nitrimino-5-nitrohexahydro-1,3,5-

triazine (100) from the Mannich condensation of nitroguanidine (98), formaldehyde and

t-butylamine, followed by nitrolysis of thet-butyl group of the resulting product, 2-nitrimino-

5-tert-butylhexahydro-1,3,5-triazine (99). The triazine (100) has also been synthesized from

the reaction of nitroguanidine and hexamine in aqueous hydrochloric acid, followed by

nitration of the resulting product (97) with a solution of nitric acid in acetic anhydride.^36

CH 3 NO 2

+ 3 CH 2 O + 2 t-BuNH 2 N

NO 2

t-Bu t-Bu

N

NO 2

O 2 N

N

O 2 N ONO 2

O 2 N NO 2

101

102

(TNHP)

103

(NMHP)

100 % HNO 3

1. CH 2 O


2. 100 % HNO 3
   NO 2

N

NN

Figure 6.27

The Mannich condensation between nitromethane, formaldehyde andt-butylamine, fol-

lowed by nitrolysis of the resulting product (101), has been used to synthesize 1,3,5-trinitro-

hexahydropyrimidine (102) (TNHP); treatment of the latter with formaldehyde in a Henry type

methylolation, followed byO-nitration with nitric acid, yields the nitrate ester (103).^37

6.9 Nitroureas

As early as 1974 French chemists^38 reported the synthesis of the nitrourea explosives 1,4-

dinitroglycouril (DINGU) (105) and 1,3,4,6-tetranitroglycouril (TNGU or Sorguyl) (106).

Their synthesis is both short and efficient: the reaction of urea with glyoxal forming glycouril

(104), which is then treated with absolute nitric acid or mixed acid to produce DINGU (105);

reaction of the latter with dinitrogen pentoxide in nitric acid yields TNGU (106).