Mar-Apr 2008
New Route for Preparation of Nitrosubstituted 1,2-Phenylenediamine
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EXPERIMENTAL
1-N-Methyl-3-nitro-1,2-phenylenediamine (2). A mixture of
5 (4 g, 12.4 mmol) and 80% sulfuric acid (30 mL) was stirred at
100°C for 7 h. Hot reaction mixture was poured into ice (50 g)
and neutralized with 10% NaOH solution while cooling. Dark
red precipitate was collected by suction, washed with water and
dried. Recrystallization from n-heptane afforded 2 as dark red
needles (0.98 g, 47%) mp 91-94°C (lit.[13] 78°C). 1H nmr
(DMSO-d6, 300 MHz): 2.76 (d, J = 4.2 Hz, 3H); 5.44 (d, J = 4.8
Hz, 1H); 6.56 (m, 2H); 7.04 (s, 2H); 7.32 (dd, J = 7.8, 2.4 Hz,
1H). 13C nmr (DMSO-d6, 75 MHz): δ 30.4, 111.8, 112.1, 115.9,
130.5, 135.6, 138.8.
Melting points were determined on Koffler’s apparatus using
digital thermometer (DT012C) and are uncorrected. The 1H
NMR and 13C NMR spectra were recorded on Varian Mercury
300-MHz spectrometer in DMSO-d6 or CDCl3 using TMS as
internal standard. Chemical shifts (δ) and coupling constants J
are given in ppm and Hz, respectively. Reaction monitoring and
purity of products was accomplished by TLC on silica-gel
plates.
1-N-Methyl-4-nitrobenzo[2.1.3]selenadiazolium methyl-
sulphate (1). A mixture of 4-nitrobenzo[2.1.3]selenadiazole
(4.56 g, 20 mmol) and freshly distilled dimethylsulfate (20 mL,
0.21 mol) was heated at 120-130°C in oil bath within 1 h. After
cooling down the reaction mixture to room temperature, the
precipitated solid was separated by suction, washed with
diethylether and dried to give 1 as light brown crystals (6.2 g,
87%), mp 182-185°C. 1 was used to the next reaction without
further purification and spectral characterization.
1-N-Methyl-3-nitro-1,2-phenylenediamine (2). To a stirred
NaOH solution (2 M, 25 mL) compound 1 (3.54 g, 10 mmol)
was added portionwise. The formed dark red suspension was
stirred for 30 minutes at room temperature. The dark red solid
was collected by suction, washed with water and dried. Dry
solid was dissolved in CH2Cl2 (20 mL), insoluble material was
filtred off and the filtrate was evaporated to dryness under
reduced pressure to afford 2 as dark red solid (1.4 g, 90%), mp
87-90°C (lit.[13] 78°C). 1H nmr (DMSO-d6, 300 MHz): 2.78 (d,
J = 4.6 Hz, 3H); 5.46 (d, J = 4.8 Hz, 1H); 6.56 (m, 2H); 7.06 (s,
2H); 7.32 (dd, J = 7.8, 2.4 Hz, 1H). 13C nmr (DMSO-d6, 75
MHz): δ 30.4, 111.8, 112.1, 115.9, 130.5, 135.7, 138.8.
1-Methyl-4-nitrobenzimidazole (3). A mixture of 2 (0.5 g, 3
mmol) and formic acid (6 mL) was refluxed for 12 h. After
cooling down the reaction mixture was diluted with water (6
mL) and then alkalized with 27% NH4OH solution. Resulting
precipitate was collected by filtration, washed with water and
dried. Recrystalization from toluene yielded 3 as yellowish
1
needles (0.24 g, 45%), mp 168-169°C (lit. [15,22] 168°C). H
nmr (CDCl3, 300 MHz): 3.95 (s, 3H); 7.40 (t, J = 8.07 Hz, 1H);
7.73 (d, J = 8.05 Hz, 1H); 8.11 (s, 1H); 8.14 (d, J = 8.07 Hz,
1H). 13C nmr (CDCl3, 75 MHz): δ 31.6, 116.1, 119.3, 122.1,
137.0, 137.2, 139.1, 146.8.
Acknowledgements. The authors are grateful to the Slovak
Grant Agency (Project 1/2448/05) and the Science and
Technology Assistance Agency APVT-20-00734 for finacial
support.
REFERENCES AND NOTES
[1] Grivas, S. Curr. Org. Chem. 2000, 4, 707.
[2] Porter, H. K. Org. React., 1973, 20, 455.
[3] Entwistle, I. D.; Jonhstone, R. A. W.; Povall, T. J. J. Chem.
Soc., Perkin Trans. 1, 1975, 1300.
[4] Devlin,T. A.; Jebaratnam, D. J. Synth. Commun., 1995, 25,
711.
[5] Griffin, K. P.; Peterson, W. D. Org. Synth. 1955, 3, 242.
[6] Milata, V.; Saloň, J. Org. Prep. Proced. Int. 1999, 31, 347.
[7] Elvidge, J. A.; Newbold, G. T.; Percival, A.; Sencial, I. R. J.
Chem. Soc. 1965, 5119.
[8] Nyhammar, T.; Grivas, S. Acta Chem. Scand. 1986. B40,
583.
1-N-Tosyl-3-nitro-1,2-phenylenediamine (4). A mixture of
3-nitro-1,2-phenylenediamine (4 g, 26 mmol), tosylchloride (5 g,
26 mmol) and pyridine (30 mL) was refluxed for 5 h. Hot
reaction mixture was poured into ice (100 g) and yellow-orange
solid formed was collected by suction, washed with water and
dried. Recrystallization from ethanol gave 4 as yellow needles
(5.62 g, 70%) mp 198-200°C (lit. [20] 192-193°C). 1H nmr
(DMSO-d6, 300 MHz): 2.37 (s, 3H); 6.50 (dd, J = 7.55 Hz, 1H);
6.87 (dd, J = 7.52, 1.54 Hz, 1H); 7.01 (s, 2H); 7.36-7.62 (dd, J =
8.20 Hz, 4H); 7.89 (dd, J = 8.74, 1.54 Hz, 1H); 9.66 (s, 1H). 13
C
[9] Grivas, S.; Tian, W. Acta Chem. Scand. 1992, 46, 1109.
[10] Grivas, S.; Tian, W. J. Heterocycl. Chem. 1992, 29, 1305.
[11] Grivas, S.; Tian, W. Synthesis 1992, 12, 1283.
[12] Kamel, M.; Ali, M. I.; Kamel, M. M. Liebigs Ann. Chem.
1970, 733, 115.
[13] Reddy, V. M.; Reddy, K. K. Indian. J. Chem. 1979, 17B,
357.
[14] Kamel, M.; Ali, M. I.; Kamel, M. M. Tetrahedron 1966, 22,
3315.
[15] Leandri, G.; Mangini, A.; Montanari, F.; Passerini, R. Gazz.
Chim. Ital. 1955, 85, 769.
[16] Nunn, A. J.; Ralph, J. T. J. Org. Chem. 1965, 6769.
[17] Ralph, J. T. Synth. Commun. 1989, 19, 1381.
[18] Pappalardo, L.; Elguero, J.; Fruchier, A. An. Quim. 1975, 71,
598.
[19] Fruchier, A.; Pappalardo, L.; Elguero, J. An. Quim. 1980, 76,
79.
[20] Harvey, I. W.; Farlane, M. D.; Moody, D. J.; Smith, D. M. J.
Chem. Soc. Perkin Trans. 1, 1988, 1939.
nmr (DMSO-d6, 75 MHz): δ 21.0, 114.2, 124.5, 124.7, 127.0,
129.7, 131.7, 133.6, 136.3, 142.8, 143.5.
1-N-Methyl-1-N-tosyl-3-nitro-1,2-phenylenediamine (5).
Derivative 4 (4.37 g, 14 mmol) was dissolved in NaOH solution
(2 M, 16 mL) and to this solution water (200 mL) was added.
Orange-red solution was heated to 30-40°C and freshly distilled
dimethylsulfate was added dropwise. After the addition was
completed the yellow precipitate was formed and colour of
solution changed to yellow. Addition of the same amounts of
reagents (16 mL of NaOH solution and 5 mL dimethylsulfate)
was repeated for 4 times. Yellow precipitate was separated by
suction, washed with water and dried. Recrystallization from
ethanol yielded 5 as yellow needles (3.85 g, 84%) mp 184-
1
189°C. H nmr (DMSO-d6, 300 MHz): 2.43 (s, 3H, Ph-CH3);
3.07 (s, 3H, N-CH3); 6.50 (dd, J = 7.57 Hz, 1H); 6.67 (dd, J =
7.51, 1.41 Hz, 1H); 7.44-7.62 (dd, J = 8.20 Hz, 4H); 7.99 (dd, J
= 8.70, 1.52 Hz, 1H). 13C nmr (DMSO-d6, 75 MHz): δ 21.1,
38.9, 114.0, 126.0, 127.9, 129.9, 130.0, 131.7, 133.3, 134.0,
144.1, 144.3. Anal. Calcd. for C14H15N3O4S: C, 52.33; H, 4.70;
N, 13.08. Found: C, 52.16; H, 4.66; N, 13.11.
[21] Katritzky, A. R.; Rachwal, S.; Rachwal, B. J. Chem. Soc.,
Perkin Trans. 1, 1987, 805.
[22] Milata, V.; Ilavský, D. Org. Prep. Proced. Int. 1993, 25, 703.