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9
7
3
9
7
3
6
9
7
3
6
O
O
OH
O
8
4
2
8
4
8
OH
O
2
4
2
11
11
O2N
11
COOH
10
O2N
O2NO
O N
OH
O2N
COOH
COOH
1
1
HO
O2N
1
H3CCOO
10
10
1) H2SO4, Ac2O
2) H2O
12
13
5
5
5
O2N
6
1
2
3
Scheme 1. Conversion of quinone-aci form into phenol-nitro form.
14
14
15
15
9
7
3
9
7
3
9
7
8
3
OOCCH3
OOCCH3
2
OH
O
8
4
8
4
4
2
2
16, 17
COOEt
11
O2N
O2N
O2N
COOH
10
COOEt
11
11
1
1
1
OH
O2N
H3CCOO
Ac2O
EtOH
Ac2O H3CCOO
16, 17
10
10
12
13
12
13
2
5
5
5
O2N
O
O2N
O
H2SO4
H2SO4
H2SO4
6
6
6
4
5
6
Scheme 2. The esters derived from 2.
2 h. The yield 28.9 g (80%), decomposed at 155 °C, the yellow color
of 1 slowly changers on storage. IR (KBr), cmÀ1: 3428 (OAH); 3089,
2931 (CAH); 1715 (carboxyl C@O); 1625 (quinone C@O); 1595
(quinone C@C). Anal. Calcd. for C11H11N3O11: C, 36.56; H, 3.05; N,
11.63. Found: C, 36.82; H, 3.27 N, 11.34.
443 mg (64%) of 5, melting at 95–97 °C. IR (KBr), cmÀ1: 3318,
3103 (OAH); 3053, 2924 (CAH); 1726 (C@O), 1571, 1531 (aromatic
C@C). Anal. Calcd. for C13H16 N2O9: C, 45.35; H, 4.65; N, 8.14.
Found: C, 45.57; H, 4.85; N, 8.44.
2.1.5. Ethyl 2-acetoxy-4-(2-acetoxy-3-nitropropyl)-5-nitrophenoxy-
acetate (6)
2.1.2. 2-Hydroxy-4-(2-hydroxy-3-nitropropyl)-5-nitrophenoxyacetic
acid (2) and 2-Hydroxy-4-(2-acetoxy-3-nitropropyl)-5-nitrophenoxy-
acetic acid (3)
A mixture of 344 mg (1 mmol) of 5 in 4 mL of acetic anhydride
and 1 drop of H2SO4 was refluxed at 50–60 °C for 2 h. The received
solution was poured into 5 mL cooled water. The precipitate was
filtered out and recrystallized from 50% by volume aqueous EtOH
to afford 254 mg (60%) of 6 melting at 123–124 °C. IR (KBr),
cmÀ1: 3075, 2988, 2938 (CAH); 1784, 1736 (C@O), 1561, 1522
(aromatic C@C). Anal. Calcd. for C17H20 N2O11: C, 47.66; H, 4.67;
N, 6.54. Found: C, 47.93; H, 4.26; N, 6.74.
To a mixture of 1.8 g (5 mmol) of 1 in 6 mL of acetic anhydride
was slowly added a solution of 0.2 mL of H2SO4 in 4 mL of acetic
anhydride. The reaction mixture was shaken and then refluxed at
55–60 °C for 2 h. The received solution was poured into 10 mL
cooled water. A small amount of solid was filtered out and recrys-
tallized from 50% by volume aqueous EtOH to afford 0.18 g (10%) of
3 melting at 169–170 °C. IR (KBr), cmÀ1: 3283 (OAH); 3050, 2931
(CAH); 1750, 1715 (C@O); 1600, 1560 (aromatic C@C). Anal. Calcd.
for C13H14N2O10: C, 43.57; H, 3.91; N, 7.82. Found: C, 43.82; H,
4.22; N, 7.58.
2.2. Physical measurements
2.2.1. Elemental analysis
The filtrate was allowed to stand at room temperature for
3 days. The resulting precipitate was collected, washed with water,
recrystallized from 50% by volume aqueous EtOH to give 0.79 g
(50%) of 2 (crystallized with 1.5 water molecules) melting at
110–111 °C. IR (KBr), cmÀ1: 3304 (OAH); 3096, 2931 (CAH);
1717 (C@O); 1590, 1519 (aromatic C@C). Anal. Calcd. for C11H12
N2O9Á1.5H2O: N, 8.16. Found: N, 7.87.
C, H and N were analysed on a LECO CHNS model 932 elemental
analyser.
2.2.2. X-ray measurements
Single-crystal X-ray diffraction is recorded on
SMART6000 diffractometer (fine-focus sealed tube, Cu K
a
Bruker
radia-
a
tion, crossed Göbel mirrors) at 100 K. A total of 18,874 reflections
were measured of which 5086 independent. The intensity data
were corrected for Lorentz and polarization effects, and for absorp-
tion (SADABS) [15]. The structure was solved by direct methods
(SHELXS-97) [16] and refined by full-matrix least-squares based
on F2 using SHELXL-97 [17] (448 parameters). Hydrogen atoms
were located in the calculated positions.
2.1.3. 2-Acetoxy-4-(2-acetoxy-3-nitropropyl)-5-nitrophenoxyacetic
acid (4)
A mixture of 343 mg (1 mmol) of 2 in 4 mL of acetic anhydride
and 1 drop of H2SO4 was refluxed at 50–60 °C for 2 h. The received
solution was poured into 5 mL cooled water. The precipitate was
filtered out and recrystallized from 50% by volume aqueous EtOH
to afford 262 mg (66%) of 4 melting at 131–132 °C. IR (KBr),
cmÀ1: 3134 (OAH); 3062, 2941 (CAH); 1782, 1738 (C@O), 1562,
1526 (aromatic C@C). Anal. Calcd. for C15H16 N2O11: C, 45.00; H,
4.00; N, 7.00. Found: C, 45.31; H, 4.17; N, 7.3.
2.2.3. IR and LC–UV–MS spectra
The IR spectra were recorded on an IMPACK-410 NICOLET spec-
trometer in KBr discs in the range 400–4000 cmÀ1. LC–UV–MS
were recorded on a Agilent LC–MSD-Trap-SL series 1100, column:
C18 150 Â 3.0, solvent: MeOH – H2O, gradient: 30% MeOH – 100%
MeOH.
2.1.4. Ethyl 2-hydroxy-4-(2-hydroxy-3-nitropropyl)-5-nitrophenoxy-
acetate (5)
A mixture of 686 mg (2 mmol) of 2 in 5 mL of EtOH and 2 drop
of H2SO4 was refluxed for 12 h. The received solution was allowed
to cool to room temperature. The precipitate was filtered out and
recrystallized from 50% by volume aqueous EtOH to afford
2.2.4. NMR data
The NMR spectra were recorded on a Bruker AVANCE 500 MHz,
all at 298–300 K, in d6-DMSO, with TMS as the internal standard.
The 1H- and 13C NMR data are listed in Tables 1 and 2.