Nucleophilic aromatic substitution 173The tri-nitration of 3,5-dichloroanisole (134) followed by ammonolysis of the product (135)
with ammonia is a much more facile route to TATB (14); although the cost and availability of
(134) makes this route of academic interest only.^277
The tri-nitration of 1,3-dimethoxybenzene with mixed acid, followed by amination, is a
patented route to DATB.^278 A similar route to TATB employing 1,3,5-trimethoxybenzene and
dinitrogen pentoxide only results in moderate yields.^30 ,^279
OHOHHONO 2NO 2
27O 2 NNH 2H 2 N NH 2NO 2NO 2
14O 2 NORORRONO 2NO 2CH(OR) O^2 N
3
R = Me, 90 %
R = Et, 85 %
R = Pr, 94 %NH 3 , PhCH 3 ,
0.8–0.9 MPa, 25 °CR = Me, 98 %
R = Et, 98.4 %
R = Pr, 99 %Figure 4.58Bellamy and co-workers^30 conducted an extensive study into the synthesis of TATB
from phloroglucinol. Phloroglucinol and its triacetate derivative were tri-nitrated to 2,4,6-
trinitrophloroglucinol (27) with mixed acid or dinitrogen pentoxide in sulfuric acid. 2,4,6-
Trinitrophloroglucinol (27) was alkylated with orthoformate esters to give the trimethoxy-,
triethoxy- or tripropoxy-2,4,6-trinitrobenzenes; subsequent amination in toluene under pres-
sure, or with liquid ammonia, gave TATB (14) in excellent yield in all three cases.
NH 2 NH 2
NO 2NO 2
NO 2
31O 2 NO 2 NNH 2H 2 N NH 2NO 2NO 2
14O 2 NO 2 N NO 2CH 3
NO 2NO 2
1O 2 NCH 3
NO 2NH 2
46O 2 NPhCH 3 , CCl 4 ,
NH 3 (gas)97 %HNO 3 , H 2 SO 452 %HNO 3 , H 2 SO 4 ,
80 °C, 47 %H 2 S, NH 4 OH,
dioxane
60 %30Figure 4.59The synthesis of TATB (14) from the reaction of 2,3,4,5,6-pentanitroaniline (31) with am-
monia has been reported.^140 ,^143 In one route, 2,3,4,5,6-pentanitroaniline (31) is synthesized
from the nitration of 3,5-dinitroaniline (30);^39 ,^139 ,^140 the latter is obtained from the selective
reduction of TNB^280 or via a Schmidt reaction with 3,5-dinitrobenzoic acid.^281 Another route
to 2,3,4,5,6-pentanitroaniline (31) involves the selective reduction of TNT (1) with hydrogen
sulfide in ammonia followed by nitration of the resulting 4-amino-2,6-dinitrotoluene (46),
during which the methyl group is lost by oxidation–decarboxylation.^143 ,^282