Synthesis of Thiadiazine Derivatives
997
then diluted with water (50 ml). The resulting solid product was col-
lected by filtration, washed with water, dried, and recrystallized from
dioxane/water. Yield 0.46 g (90.2%) of compound 10b as yellow crys-
tals, m.p. 220–222 C; (Found: C, 45.70; H, 3.77; N, 10.85; S, 12.34.
C20H19N4O4S2Br (523.43) requires C, 45.89; H, 3.65; N, 10.70; S,
12.25%); max/cm 1: 3450-3350 (NH2), 3050 (Ar CH), 1720, 1690, 1680
(CO); H (DMSO-d6): 1.30 (t, J 7 Hz, 3H, COOCH2CH3), 2.90 (t, J 5.6 Hz,
2H, H-5), 3.60 (t, J 5.6 Hz, 2H, H-6), 4.10 (q, J 7 Hz, 2H, COOCH2CH3),
4.50 (s, 2H, S CH2), 4.60 (s, 2H, H-8), 5.70 (s, 2H, NH2), 7.60 (d, J 7.7 Hz,
2H, Ar H), 8.08 (d, J 7.7 Hz, 2H, Ar H).
Ethyl 2-phenyl-11-oxo-9,10-dihydro-3H,11H-pyrido-
[400,300:40,50]thieno[20,30:4,5]pyrimido[2,1-b][1,3,4]-
thiadiazine-8(7H)-carboxylate (11a)
The solution of compound 10a (0.44 g, 0.001 mol) in ethanol (10 ml),
p-toluenesulfonic acid (20 mg) was refluxed for 2 h. After cooling, the
solid product was collected by filtration, washed with warm ethanol,
dried, and recrystallized from dioxane. Yield 0.3 g (71.4 %) of compound
11a as yellow crystals, m.p. 256–257 C; (Found: C, 56.18; H, 4.32; N,
13.05; S, 14.90. C20H18N4O3S2 (426.52) requires C, 56.32; H, 4.25; N,
13.13; S, 15.03%); max/cm 1: 3050 (Ar CH), 1710, 1680 (CO), 1640
(C N);
(DMSO-d6): 1.20 (t, J 7 Hz, 3H, COOCH2CH3), 2.90 (t, J
H
5.6 Hz, 2H, H-10), 3.70 (t, J 5.6 Hz, 2H, H-9), 4.20 (q, J 7 Hz, 2H,
COOCH2CH3), 4.30 (s, 2H, S CH2), 4.60 (s, 2H, H-7), 7.70–8.10 (m,
5H, Ar–H).
Ethyl 2-(4-bromophenyl)-11-oxo-9,10-dihydro-3H,11H-
pyrido[400,300:40,50]thieno[20,30:4,5]pyrimido[2,1-b][1,3,4]-
thiadiazine-8(7H)-carboxylate (11b)
The solution of compound 10b (0.52 g, 0.001 mol) in ethanol (10 ml),
p-toluenesulfonic acid (20 mg) was refluxed for 2 h. After cooling, the
solid product was collected by filtration, washed with warm ethanol,
dried, and recrystallized from dioxane. Yield 0.35 g (70%) of com-
pound 11b as yellow crystals, m.p. 255–257 C; (Found: C, 47.44; H, 3.28;
N, 10.94; S, 12.51. C20H17N4O3S2Br (505.41) requires C, 47.52; H, 3.38;
N, 11.08; S, 12.68%); max/cm 1: 3080 (Ar CH), 1730, 1710 (CO);
H
(DMSO-d6): 1.20 (t, J 7 Hz, 3H, COOCH2CH3), 2.80 (t, J 5.6 Hz, 2H,
H-10), 3.70 (t, J 5.6 Hz, 2H, H-9), 4.10 (q, J 7 Hz, 2H, COOCH2CH3),
4.30 (s, 2H, CH2), 4.60 (s, 2H, H-7), 7.70 (d, J 8 Hz, 2H, Ar H), 7.90 (d,
J 8 Hz, 2H, Ar H).