Organic Chemistry of Explosives

112 Synthetic Routes to Nitrate Esters

C

CH 2 ONO 2

CH 3

CH 2 ONO 2

C CH 2 OH

CH 2 ONO 2

CH 3

CH 2 ONO 2

CH 2 OAcC

CH 2 OH

CH 3

CH 3

CH 2 OH

CH 2 OAc

C

CH 2 OAc

CH 2 OAc

CH 2 OH C

CH 2 OAc

CH 3

CH 2 OAc

CH 2 ONO 2 C

CH 2 OH

CH 3

CH 2 OH

CH 2 ONO 2

90 91 92

93 94 95

90 % HNO 3

90 % HNO 3

0 °C, 64 %

0 °C, 73 %

1. NaOH


2. HCl

57 %

1. NaOH


2. HCl

75 %

Figure 3.43

Marans and Preckel^148 synthesized both the mononitrate (95) and the dinitrate (92) esters of

metriol by using a similar strategy to that used for pentaerythritol trinitrate. Thus, nitration of

both the mono- (90) and the di- (93) acetate esters of metriol, followed by selective hydrolysis

of the acetate groups, yields (92) and (95) respectively; the latter could be useful as a monomer

for the synthesis of energetic polyurethane polymers.

3.10 Energetic nitrate esters

Nitrate esters are a class of powerful explosives and this is mainly attributed to their better

oxygen balance compared to aromatic nitro compounds. However, far fewer examples of

energetic nitrate esters are available compared to energetic nitramines,C-nitro compounds

andN-heterocycles. This is undoubtedly due to the presence of the –O–NO 2 bond, which is

weaker than the –N–NO 2 and –C–NO 2 bonds, resulting in higher sensitivity to mechanical and

thermal stimuli. Most modern research is heavily focused on synthesizing insensitive energetic

materials and the nitrate ester group is not always conducive to this.

HO

OH

O 2 NO

KF, N 2 O 5 , CH 2 Cl 2 ONO 2

Br

Br Br

Br

3 steps

ONO 2

O 2 NO ONO 2

O 2 NO

96 97

(^9899)
Figure 3.44
Some examples of nitrate ester incorporation into caged molecules have been reported:
1,3,5,7-tetranitroxyadamantane (97)^149 has been synthesized in three steps from 1,3,5,7-
tetrabromoadamantane (96) and 1,4-dinitroxycubane (99)^150 has been synthesized from the
nitration of the corresponding diol (98).