Organic Chemistry of Explosives

6-Membered rings – 2N 319

methoxy group which then allows nitration in the 3- and 5-positions under moderate conditions

to yield (182), nucleophilic displacement of both methoxy and chloro groups with ammonium

hydroxide in acetonitrile yielding 2,6-diamino-3,5-dinitropyrazine (ANPz) (183).^7 Treatment

of ANPz (183) with aqueous peroxytrifluoroacetic acid yields theN-oxide (LLM-105) (184),

an explosive showing high thermal stability (decomposition point of 354◦C).^7 The conversion

of ANPz (183) (d= 1 .84 g/cm^3 )totheN-oxide (184) (d= 1 .918 g/cm^3 ) illustrates a useful

strategy for increasing the crystal density of nitrogen heterocycles.

N

N

H 2 N NH 2

O 2 N

N

N

H 2 N NH 2

O 2 N

O

N

N

OMeCl

O 2 N

N

N

N OMeCl

N

ClCl

NaOMe

180 181

184

(LLM-105)

182

H 2 SO 4 ,

HNO 3 , 70 °C

NH 4 OH,

MeCN,

60 °C

TFA, 30 % H 2 O 2

183

(ANPz)

NO 2

NO 2 NO 2

Figure 7.67

187

N

N

NHHN

NH

O 2 N

NO 2

NO 2

O 2 N

NO 2

NO 2 NO 2

NO 2

O 2 NO 2 N

N

N

O 2 N

NO 2

NH 2

NH 2

O

O

N

N

H 2 N NO 2

O 2 N

185

186

NH 2

Figure 7.68

Millar and co-workers reported the synthesis of a number of energetic pyrimidines, pyrazines

and their bicyclic analogues, including 2,5-diamino-3,6-dinitropyrazine (185) and the quina-

zoline (186).^117 ,^118

Chemists at Los Alamos National Laboratory synthesized a series of picrylamino-

substituted pyrimidines as part of a research effort to find new thermally stable explosives. The

pyrimidine-based explosive (187) is synthesized via the reaction of 2,4,6-triaminopyrimidine

with picryl fluoride followed by subsequent nitration with nitric acid.^119