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M.A.E. Shaban et al. / Il Farmaco 54 (1999) 800–809
3.1.5.3. 3 - (4 - Chlorobenzylidenehydrazino) - 5 - methyl -
1,2,4-triazino[5,6-b]indole (12e). Yield: 75%; yellow
needles; m.p.: 316°C; TLC in 9:1 chloroform–
3.1.6.4. Method (D). A mixture of 3-benzoylhydrazino-
5-methyl-1,2,4-triazino[5,6-b]indole (5c, 1 g) in glacial
acetic acid (20 ml) was heated at 100°C for 3 h. The
reaction mixture was evaporated and the resulting
residue was crystallized from ethanol to give 10c (52%)
as orange needles, m.p.: 330°C, identical in every re-
spect to 10c prepared according to methods A, B and
C. The following compounds were prepared according
to methods A–C.
1
methanol, Rf: 0.71; IR: 1595, 1610 cm−1 (CꢀN); H
NMR (CF3COOD): l 3.80 (s, 3H, CH3), 7.80 (m, 9H,
ArH+CHꢀN). Anal. Calc. for C17H13N6Cl (336.5).
3.1.5.4. 3 - (4 - Bromobenzylidenehydrazino) - 5 - methyl -
1,2,4-triazino[5,6-b]indole (12f). Yield: 80%; yellow
needles, m.p.: 318°C; TLC in 9:1 chloroform–
1
methanol, Rf: 0.60; IR: 1600, 1625 cm−1 (CꢀN); H
3.1.6.5. 10 - Methyl - 3 - phenyl - 1,2,4 - triazolo[4%,3%:2,3] -
1,2,4-triazino[5,6-b]indole (10c). Yield: method (A),
65%; method (B); 43%; method (C), 50%; orange
needles, m.p: 330°C, Ref. [18] 336; TLC in 9:1 chloro-
form-methanol, Rf: 0.22; IR: 1600 cm−1 (CꢀN); 1H
NMR (CF3COOD): l 4.05 (s, 3H, CH3), 8.35 (m, 9H,
ArH). Anal. Calc. for C17H12N6 (300).
NMR (CF3COOD): l 3.85 (2, 3H, CH3), 7.90 (m, 9H,
ArH+CHꢀN). Anal. Calc. for C17H13N6Br (381).
3.1.5.5. 3-(4-N,N-Dimethylaminobenzylidenehydrazino)-
5-methyl-1,2,4-triazino[5,6-b]indole (12g). Yield: 71%;
orange needles; m.p.: 243°C, Ref. [7] 296°C; TLC in 9:1
chloroform–methanol; Rf: 0.62; IR: 1557, 1606 cm−1
1
3.1.6.6. 3-(4-Methoxyphenyl)-10-methyl-1,2,4-triazolo-
[4%,3%:2,3]1,2,4-triazino[5,6-b]indole (10d). Yield: method
(A), 52%; method (B), 39%; method (C), 45%; orange
needles, m.p.: 312°C; TLC in 9:1 chloroform–mehonol,
Rf: 0.36; IR: 1607 cm−1 (CꢀN); 1H NMR (CF3COOD):
l 3.95, 4.05 (2s, 3H each, CH3), 8.00 (m, 8H, ArH).
Anal. Calc. for C18H14N6O (300).
(CꢀN); H NMR [(CD3)2SO]: l 3.00 (s, 6H, N(CH3)2),
3.80 (s, 3H, CH3), 7.50 (m, 9H, aromatic H+CHꢀN).
Anal. Calc. for C19H19N7 (345).
3.1.5.6. 3-(4-Nitrobenzylidenehydrazino)-5-methyl-1,2,4-
triazino[5,6-b]indole (12h). Yield: 84%; orange needles;
m.p.: 376°C, Ref. [7] 300°C; TLC in 9:1 chloroform–
1
methanol, Rf: 0.58; IR: 1605, 1635 cm−1 (CꢀN); H
3.1.6.7. 3-(4-Chlorophenyl)-10-methyl-1,2,4-triazolo-
[4%,3%:2,2]1,2,4-triazino[5,6-b]indole (10e). Yield: method
(A), 57%; method (B), 48%; method (C), 46%; orange
needles, m.p.: 360°C Ref. [18] 348°C; TLC in 19:1
chloroform–methanol, Rf: 0.41; IR: 1601 cm−1 (CꢀN);
1H NMR (CF3COOD): l 4.05 (s, 3H, CH3), 8.10 (m
8H, ArH). Anal. Calc. for C17H11N6Cl (334.5).
NMR (CF3COOD): l 3.95 (s, 3H, CH3), 8.20 (m, 9H,
ArH+CHꢀN). Anal. Calc. for C17H13N7O2 (347).
3.1.6. General procedure for the preparation of 3-aryl-
10-methyl-1,2,4-triazolo[4%,3%: 2,3]1,2,4-triazino-
[5,6-b]indoles (10c–h)
3.1.6.1. Method (A). A suspension of the particular
3-arylidenehydrazino-5-methyl-1,2,4-triazino[5,6-b]-
indole (12c–h, 2 mmol) in dioxane (5 ml) was treated
with 30% aqueous sodium hypochlorite solution (15 ml)
and the mixture was heated at 100°C for 10 min. The
product, obtained after attaining ambient temperature,
was filtered, washed with water, dried and crystallized
from ethanol.
3.1.6.8. 3-(4-Bromophenyl)-10-methyl-1,2,4-triazolo-
[4%,3%:2,3]1,2,4-triazino[5,6-b]indole (10f). Yield: method
(A), 62% method (B), 54%; method (C), 56%; orange
needles, m.p.: 370°C; TLC in 19:1 chloroform, Rf: 0.40;
1
IR: 1601 cm−1 (CꢀN); H NMR (CF3COOD): l 3.80
(s, 3H, CH3), 8.00 (m, 8H, ArH). Anal. Calc. for
C17H11N6Br (379).
3.1.6.9. 3 - (4 - N,N - Dimethylaminophenyl) - 10 - methyl -
1,2,4-triazolo[4%,3%:2,3]1,2,4-triazino[5,6-b]indole (10g).
Yield: method (A), 55%; method (B), 41%; method (C),
42%; orange needles, m.p.: 315°C; TLC in 9:1 chloro-
3.1.6.2. Method (B). A suspension of the particular
hydrazone (12c–h, 2 mmol) in toluene (30 ml) was
treated with 10% ethanolic iron (III) chloride solution
(20 ml) and heated at reflux for 3 h. The mixture was
evaporated to dryness and the obtained residue was
triturated with water, filtered, washed with water and
crystallized from ethanol.
1
form–methanol, Rf: 0.69; IR: 1606 cm−1 (CꢀN); H
NMR (CF3COOD): l 3.50 (s, 6H, N(CH3)2), 3.90 (s,
3H, CH3), 8.00 (m, 8H, ArH). Anal. Calc. for C19H17N7
(343).
3.1.6.3. Method (C). A mixture of the appropriate
hydrazone (12c–h, 2 mmol) and thionyl chloride (25
ml) was heated at reflux for 5 h. The mixture was
evaporated and the resulting residue was crystallized
from ethanol.
3.1.6.10. 10-Methyl-3-(4-nitrophenyl)-1,2,4-triazolo-
[4%,3%:2,3]1,2,4-triazino[5,6-b]indole (10h). Yield: method
(A), 67%; method (B), 63%; method (C), 57%, orange
needles; m.p.: 407°C; TLC in 19:1 chloroform–
1
methanol, Rf: 0.35; IR: 1601 cm−1 (CꢀN); H NMR