Halide displacement 11
in alkaline solution. These reactions are believed^100 to go via the tautomericα-halonitronic acid
(12) rather than theα-halonitroalkane (11). The synthesis of internalgem-dinitroaliphatic com-
pounds from the corresponding internalα-halonitroalkanes is not possible via this route. Theα-
halonitroalkane substrates for the Ter Meer reaction are readily obtained from the bromination^62
or chlorination^101 of primary nitroalkanes in alkaline solution, or from the reaction of halo-
genating agents with oximes followed by oxidation of the resultingα-halonitrosoalkane.^102 ,^103
H 2 SO 4
CH 3 NO 2
16
HOCH 2 CH 2 OH
NO 2
NO 2
KNO 2 , NaOH (aq)
CCH 2 OH
O 2 N
KO 2 N
20
ClCH 2 NO 2
17
K
+ −
CH(NO 2 ) 2
18
19
H CH 2 OH C
NO 2
NO 2
21
C
- NaOH
- Cl 2 25 %
95 % (2 steps)
AcOH,
CH 2 O, 66 %
1 eq KOH (aq)
99 %
Figure 1.10
The Ter Meer reaction has been used for the synthesis of the potassium salt of dinitromethane
(18) by treating chloronitromethane (17) with potassium nitrite in aqueous sodium hydroxide
solution.^104 The potassium salt of dinitromethane is a dangerous shock sensitive explosive and
should not be isolated; treatment of (18) with formaldehyde in acidic solution forms the more
manageable bis-methylol derivative, 2,2-dinitro-1,3-propanediol (19).^104 Partial hydrolysis of
(19) with potassium hydroxide, followed by acidification, yields 2,2-dinitroethanol (21).^105
2,2-Dinitroethanol has also been synthesized from the alkaline bromination of 2-nitroethanol
followed by nitrite displacement and subsequent acidification of the resulting potassium 2,2-
dinitroethanol.^106 2,2-Dinitro-1,3-propanediol and 2,2-dinitroethanol are useful derivatives of
dinitromethane and find extensive use in condensation and esterification reactions for the
synthesis of energetic oligomers and plasticizers.
CH 3 CH 2 NO 2
K 2 CO 3 (aq)
CH 3 CH(NO 2 ) 2
H+
C
NO 2
NO 2
CH 3 CH 2 OH
CH 3 CH(NO 2 )Cl
KNO 2
CH 3 C
NO 2 K
NO 2
CH 2 O
- NaOH (aq)
- Cl 2
93 % (2 steps)
25
26
pH 4--4.5
23
24
22
(70 % from 23)
Figure 1.11
Both 1,1-dinitroethane (26) and 1,1-dinitropropane, and their methylol derivatives, 2,2-
dinitropropanol (25) and 2,2-dinitro-1-butanol respectively, have been synthesized via the Ter
Meer reaction.^99 ,^107 The formal and acetal of 2,2-dinitropropanol in the form of a 1:1 eutectic is
an energetic plasticizer and so the synthesis of 2,2-dinitropropanol has been the subject of much
investigation.^107 On a pilot plant scale 2,2-dinitropropanol (25) is synthesized in 60 % overall
yield from nitroethane (22). Thus, treatment of 1-chloronitroethane (23) with potassium nitrite