Organic Chemistry of Explosives

5-Membered rings – 2N 299

4-amino-4′-nitro-3,3′-azofurazan (29).^25 The use of stronger hydrogen peroxide solutions can

oxidize both amino groups and yield either DNAzBF (30)^24 or DNABF (31).^24

N

O

N

2 N NO

N

O

N

N NO 2

N

O

N

2 N NO

N

O

N

N NO 2

30

(DNAzBF)

31

(DNABF)

O

Figure 7.13

Oxidation of 4,4′-diamino-3,3′-bifurazan (DABF) (32) with 90 % hydrogen peroxide in

trifluoroacetic acid yields 4,4′-dinitro-3,3′-bifurazan (DNBF) (33).^17 DNBF exhibits high per-

formance (VOD∼8800 m/s,d= 1 .92 g/cm^3 ) coupled with a conveniently low melting point

(85◦C) permitting the casting of charges. However, it is very sensitive to impact, demanding

stringent safety measures during synthesis and handling.

N

ONNO

N

H 2 N NH 2

N

ONNO

N

NO 2

NO 2

NO 2 NO 2

O 2 N

O 2 NNOO 2 N 2

N

ONNO

N

NH HN

34

(BPABF)

33

(DNBF)

32

(DABF)

TFA, 90 % H 2 O 2

2,4,6-(NO 2 ) 3 C 6 H 2 F

Figure 7.14

Some energetic compounds have picryl groups (2,4,6-trinitrophenyl-) introduced as sub-

stituents in the 3- and 4-positions of the furazan ring. Coburn^17 synthesized a series of

picrylamino-substituted furazans, including 4,4′-bis(picrylamino)-3,3′-bifurazan (BPABF)

(34) from the reaction of 4,4′-diamino-3,3′-bifurazan (DABF) (32) with two equivalents of

picryl fluoride.

N

O

N

H 2 N NH 2

F

NO 2

NO 2

O 2 N

N

O

N

H

2 N NH

O 2 N

O 2 N

NO 2

N

O

N

H

2 N NO

O 2 N

O 2 N

NO 2

24

(DAF)

+

36

37

TFA,

90 % H 2 O 2

35

Figure 7.15