Organic Chemistry of Explosives

14 Synthetic Routes to AliphaticC-Nitro

The reactions of alkyl halides with the silver salt of dinitroacetonitrile have been shown to

be of limited use for the synthesis of polynitroaliphatic compounds.^109 ,^117 These reactions give

a mixture ofC-,N- andO-alkylation products with product distribution highly dependent on

the nature of the substrate.^109 ,^117

R

HO 2 N R

Cl

41

NO 2

R

CCNO 2 H

Cl

O 2 N NO 2

R R

39

R

NO 2 −

Cl

40

43

+ +Cl

−

CC

R

−O 2 N R

Cl

42

CC NO 2

−H+

−Cl−

CC

Figure 1.16

The addition ofα-chloronitroalkanes to solutions of alkali metal hydroxide has been used

for the synthesis of some 1,2-dinitroethylene derivatives (43).^118 ,^119 These reactions involve

attack of the nitronate salt (40) on theaci-form (39) of the unreactedgem-chloronitroalkane

followed by formal loss of hydrogen chloride. 2,3-Dinitro-2-butene and 3,4-dinitro-3-hexene

(45) are formed in this way from 1-chloro-1-nitroethane and 1-chloro-1-nitropropane (44)

respectively.^118

O 2 N NO 2

CH 3 CH 2 CH 2 CH 3

2 CH 3 CH 2 CH(NO 2 )Cl

44

45

29-32%

2 eq KOH (aq)

CC

Figure 1.17

In a related reaction to that described above, nitronate salts have been reacted with

α-chloronitroalkanes as a route to polynitroaliphatic compounds.^120 2,3-Dimethyl-2,3-

dinitrobutane (48) is formed from the reaction of the nitronate salt of 2-nitropropane (46)

with 2-chloro-2-nitropropane (47).^120 A modification to the original process uses nitronate

salts in the presence of iodine to form anα-iodonitroalkanein situ.^121

CH 3 C

NO 2 Na

CH 3

46

Cl CH 3

NO 2

CH 3

47

H 3 CCC

NO 2 NO 2

CH 3

CH 3 CH 3

29%

EtOH (aq)

48

+ C

Figure 1.18

1.6 Oxidation and nitration of C–N bonds

1.6.1 Oxidation and nitration of oximes

Methods used for the oxidation or nitration of C–N bonds have found wide use for the synthesis

of novel polynitropolycycloalkanes as can be seen in Chapter 2. The conversion of readily