Organic Chemistry of Explosives

Bicycles 271

H 2 N

OH

57

NsHN NHNs

OH

58

NNNs

O 2 N NO 2

O

62

NNNs

OO

NOH

NNNs

OO

OO

NHNsNsHN

Br Br

Ns = p-NO 2 C 6 H 4 SO 2

59

6061

p-NO 2 C 6 H 4 SO 2 Cl,

K 2 CO 3 , THF (aq)

95 %

1. CrO 3 , AcOH


2. HOCH 2 CH 2 OH,
   TsOH, PhCH 3
   82 % (2 steps)

K 2 CO 3

76 %

1. O 3 , CH 2 Cl 2 ,
   -78 °C


2. Me 2 S


3. NH 2 OH.HCl,
   NaOAc, EtOH
   86 % (3 steps)


4. HNO 3 , NH 4 NO 3 ,
   urea, 33 %


5. conc. H 2 SO 4
   92 %

F 2 NSO 3 H,

HNF 2 ,

H 2 SO 4 ,

CFCl 3

90 %

HNO 3 , SbF 5 ,

CF 3 SO 3 H

NH 2

NsNsNs

NNNs

NF 2

NO 2

F 2 N

O 2 N

Ns

63

NN

NF 2

NO 2

NO 2

F 2 N

O 2 N

O 2 N

64

(TNFX)

Figure 6.15

Chapman and co-workers^17 also reported the synthesis of 3,3-bis(difluoroamino)octahydro-

1,5,7,7-tetranitro-1,5-diazocine (64) (TNFX). The synthesis of TNFX (64) starts from commer-

cially available 1,3-diamino-2-propanol (57), which is elaborated in seven steps using standard

organic reactions to give the oxime (61). Oxidation–nitration of the oxime (61) with ammo-

nium nitrate in absolute nitric acid, followed by hydrolysis of the 1,3-dioxalane functionality

with concentrated sulfuric acid, yields the required 1,5-diazocin-3-(2H)-one (62). Introduction

of difluoroamino functionality into the 1,5-diazocine ring is achieved by treating the ketone

(62) with a mixture of difluoramine and difluorosulfamic acid in sulfuric acid. Nitrolysis of the

N-nosyl amide bonds of (63) was found to be challenging – treatment of (63) with a solution

of nitric acid in triflic acid is not sufficient to effect the nitrolysis of bothN-nosyl amide bonds.

However, the addition of the Lewis acid, antimony pentafluoride, to this nitrating mixture

was found to affect nitrolysis within a reasonable reaction time, possibly by increasing the

concentration of protonitronium ion presence in solution.

6.6 Bicycles

2,4,6,8-Tetranitro-2,4,6,8-tetraazabicyclo[3.3.0]octane (bicyclo-HMX) (69) has seen consid-

erable research efforts focused into its preparation.^18 −^21 Interest in bicyclo-HMX arises from

its increased rigidity compared to HMX, a property which should result in higher density and