Organic Chemistry of Explosives

Nitration of chloramines 207

successfully used for cyclic amideN-nitration and for nitrolysis.^59 More work needs to be

reported before the scope of this reagent for nitramine synthesis can be assessed. The same

reagent has proven particularly successful for aromatic nitration.^60

Despite the amount of research focused on theN-nitration of amines with nonacidic

reagents, the use of conventional acidic reagents based on nitric acid and acid anhydrides

has been far more extensive for the synthesis of energetic materials.

5.4 NITRATION OF CHLORAMINES

5.4.1 Nitration of dialkylchloramines

HOCl

R^1 R^2 NH^1 R^2 NCl R^1 R^2 NNO 2 (Eq. 5.12)R

HNO 3 , Ac 2 O

Figure 5.27

The role of dialkylchloramines as intermediates in the chloride-catalyzed nitration of secondary

amines is discussed in Section 5.3.1. Wright and co-workers^49 studied this reaction further

and prepared a number of dialkylchloramines by treating secondary amines with aqueous

hypochlorous acid (Equation 5.12). Treatment of these dialkylchloramines with nitric acid in

acetic anhydride forms the corresponding secondary nitramine, a result consistent with the

chloride-catalyzed nitration of amines.^49

Cl N

CH 2 CH 2 ONO 2

CH 2 CH 2 ONO 2

52

O 2 N

CH 2 CH 2 ONO 2

CH 2 CH 2 ONO 2

7

HNO 3 , Ac 2 O

96 %

N

Figure 5.28

Wright and co-workers^49 preparedN-nitrodiethanolamine dinitrate (7) (DINA) in 96 %

yield by treating the chloramine (52) with a mixture of nitric acid in acetic anhydride. The

synthesis is of theoretical interest only.

5.4.2 Nitration of alkyldichloramines

RNH 2 RNCl 2 RNHNO 2 (Eq. 5.13)

2 HOCl

RN(NO 2 )Cl

HNO 3 , Ac 2 O NaHSO 3 (aq)

Figure 5.29

Wright and co-workers^61 prepared a number of alkyldichloramines from the action of

hypochlorous acid on primary amines and found these stable enough in acidic solution to

undergo nitration with acetic anhydride–nitric acid mixtures to give the correspondingN-

chloronitramines (Equation 5.13).N-Chloronitramines are isolatable intermediates and stable

under acidic conditions, although some are sensitive and violent explosives. The presence of