212
B.B.BALDANIYA
Experimental
Melting points were taken in open capillaries using paraffin bath and are uncorrected. IR
1
spectra were recorded on FTIR-Perkin-Elmer spectrometer (Vmax in cm-1); H NMR spectra
were recorded on BRUKER AVANCE 300 FT-NMR spectrometer using CDCl3 as a solvent
and mass spectra carried out on JEOL SX 102/DA-600 mass spectrometer respectively. All
the compounds were analyzed for carbon, hydrogen and nitrogen and the result were
within 0.4% of theoretical values. Purity was checked by TLC using TLC aluminum sheets
silica gel 60, supplied by E.Merck. The spots were located by keeping the plates in iodine
vapor. 6,7-Dichloro-1,3-benzothiazol-2-amine was prepared by methods as described in
literature18-19
.
6-Chloro-N, N’-bis (6,7-dichloro-1,3-benzothiazol-2-yl)-1,3,5-triazine-2,4-diamine (3)
In a conical flask, 2,4,6-trichloro-1,3,5-triazine (1) (0.01 mol) was taken in acetone (20 mL)
and 6,7-dichloro-1,3-benzothiazol-2-amine (2) (0.02 mol) was added to it. To this mixture,
4% NaOH was added drop wise at room temperature. The solution was stirred for 4 h. The
reaction mixture was poured onto crushed ice with constant stirring. The solution was
neutralized with dil. HCl. The solid was filtered and washed with water. The product was
recrystallized from acetone. m.p. 250 ºC; yield 79.00%. Anal. Found; C, 37.15; N, 17.80;
cal. for C17H6Cl5N7S2: C, 37.01; N, 17.84%.
N2,N4-Bis(6,7-dichloro-1,3-benzothiazol-2-yl)-N6-phenyl-1,3,5- triazine-2,4,6-
triamine (4a)
In a round bottom flask, 6-chloro-N, N’-bis (6, 7-dichloro-1, 3-benzothiazol-2-yl)-1, 3,
5-triazine-2, 4-diamine. (3) (0.01 mol) and 1,4-dioxane (20 mL) was taken. To this
mixture, aniline (0.01 mol) was added. The pH was adjusted to neutral by adding 8%
NaOH. This the reaction mixture was refluxed for 2.5 h. and was poured onto crushed
ice with constant stirring. The mixture was then neutralized with dil. HCl. The product
was filtered and washed with cold water. The product was dried and recrystallized from
methanol. m.p. 215 ºC; Yield 68% Anal. Found; C, 45.56; N, 18.40; cal. for
C23H12Cl4N8S2: C, 45.50; N, 18.40%.
IR (KBr): 3454 (-N-H str.,sec.amine), 3083 (-C-H str., aromatic),1527 (> C = N- str.,
ter. amine),1350 (C-NO2 str., aromatic),1122 (C-S-C str., thiazol),952 (C-Cl str.,
aromatic),808 (disubstituted aromatic),1431 (C = N str., sec.amine), 1H NMR(CDCl3): 10.08
δ (s, -NH-, 2H),9.44 δ (s, -NH-, 1H),6.54 – 7.6 δ (m, Ar-H, 8H), MS: m/z 604.01 with 68%
relative intensity [M+]. The compounds (4b-u) similarly prepared, their m.p.s and yields are
given in Table 1.
Biological activity
Antibacterial activity
Antibacterial activity was carried out by broth dilution method17. Concentrations of 1000,
500, 200, 100, 50, 25, 12.5 µg/mL respectively (Table 2).
Antifungal activity
Same compounds were tested for antifungal activity against C. albicans A. niger and A.
clavatus at a concentrations of 1000, 500, 200, and 100 µg/mL respectively (Table 2). The
result of this test is affected by the size of the inoculum. The test mixture should contain 108
organisms/mL. The standard drug used in the present study was “Gentamycin” for evaluating
Baldaniya
