Organic Chemistry of Explosives

Primary nitramines as nucleophiles 239

5.13.3 Condensations with formaldehyde

2 RNHNO 2 + CH 2 O

90 % H 2 SO 4

+ H 2 O

212, R = Me, 39 %

213, R = Et, 43 %

214, R = n-Bu, 48 %

O 2 NNO 2

RR

NN

Figure 5.88

The condensation of a primary nitramine with formaldehyde in the presence of concentrated sul-

furic acid is a useful route to 1,3-dinitramines. A number of linear dinitramines have been pre-

pared via this route including 2,4-dinitro-2,4-diazapentane (212), 3,5-dinitro-3,5-diazaheptane

(213), and 5,7-dinitro-5,7-diazaundecane (214).^165

(CH 2 O)n

H 2 SO 4 , < 0 °C

90 %

N

N

NO 2

NO 2

88

2

NHNO 2

NHNO 2

Figure 5.89

The condensation of ethylenedinitramine (2) with paraformaldehyde in the presence of

sulfuric acid at subambient temperature yieldsN, N′-dinitroimidazolidine (88).^165

OCN N

NO 2

NCO OCN

N

N NCO

NO 2

NO 2

OCN

NNO 2

O 2 NNO 2

215 216 217

2

Figure 5.90

Under aqueous conditions formaldehyde reacts with primary nitramines to form the corre-

sponding methylol derivatives. The versatility of the terminal hydroxy group of these methylol

derivatives is illustrated by their facile conversion to more reactive functional groups, like

isocyanates, which can then be reacted with compounds containing hydroxy or carboxy func-

tionality. Diisocyanates like (215), (216) and (217) have been reacted with various polyni-

troaliphatic diols for the synthesis of energetic polymers.^166

NHNO 2 O 2 NHN N

NN

NHNO 2

NO 2

218

N NHNO 2

NO 2

218

O 2 NHN NHNO 2 + O 2 NHN

NO 2 NO 2

NH 2 NO 2

161

NHNO 2

DMSO

DMSO

168

220

168

+

65–70 °C

65–70 °C

2 O 2 NHN

2 O 2 NHN

Figure 5.91