4
Sep-Oct 2006
Isonicotinoylhydrazothiazoles and Isonicotinoyl-N -substituted thiosemicarbazides
1341
1
-Isonicotinoyl-4-allylthiosemicarbazide (2d).
in 50 mL of isopropanol is stirred and heated under reflux until
complete dissolution of the reagents and for a further 1.5 hours.
The solution is then allowed to cool to room temperature, thus
obtaining a solid that is purified by crystallisation with alcohol
and dried.
1
H-NMR (DMSO-d ): ꢀ 4.21 (t, 2H, J = 5.4, NHCH ); 5.22
6
2
(dd, 2H, J = 15.74, 10.7, 1.5, =CH ); 5.90-5.99 (m, 1H, CH=);
2
7
.93 (dd, 2H, J = 4.6, 1.5, C H and C H-pyr); 8.50 (s, 1H, NH,
3 5
D-exch.); 8.87 (dd, J = 4.6, 1.5, 2H, C H and C H-pyr); 9.59 (s,
1
2
6
1
3
The following listed compounds were synthesized using this
procedure.
H, NH, D-exch.); 10.78 (s, 1H, NH, D-exch.). C-NMR
(DMSO –d ): 44.15, 70.32, 104.06, 122.83, 144.13, 145.96,
6
1
65.34, 181.77.
N'-(3,4-Dimethylthiazole-2(3H)-ylidene)isonicotinohydrazide
hydrochloride (3b).
General Procedure for the Synthesis of N'-(3,4-Disubstitutedthia-
zole-2(3H)-ylidene)isonicotinohydrazides•HBr 3a, 3c, 3e, and 3g.
1
H-NMR (DMSO): ꢀ 2.20 (s, 3H, thiaz-CH ); 3.60 (s, 3H, N-
3
CH ); 6.62 (s, 1H, C H-thiaz); 8.27 (dd, 2H, J = 4.9, 1.1, C H
3
5
3
The opportune 1-isonicotinoyl-4-substituted-thiosemicarba-
zide (4.8 mmol) is allowed to react with 2-bromoacetophenone
and C H-pyr); 8.92 (dd, 2H, J = 4.6, 1.1, C H and C H-pyr);
5
2
6
1
3
1
9
1.68 (s, 1H, NH, D-exch.). C-NMR (DMSO-d ): ꢀ 13.7, 31.0,
(4.8 mmol) suspended in 40 mL of isopropanol. The reaction
6
8.0, 121.5, 121.8, 140.0, 149.8, 164.4, 167.1
mixture is stirred for 2 hours at room temperature (monitored by
TLC). The solvent is then removed under reduced pressure and
the resulting precipitate is purified by crystallisation with
ethanol and dried.
The following listed compounds were synthesized using this
procedure.
N'-(3-Phenyl-4-methylthiazole-2(3H)-ylidene)isonicotino-
hydrazide hydrochloride (3d).
1
H-NMR (CDCl ): ꢀ 2.15 (s, 3H, thiaz-CH ); 5.77 (s, 1H,
3
3
C H-thiaz); 6.96 (d, 2H, J = 7.6, Ar); 7.09 (t, 1H, J = 7.6, Ar);
5
7
8
.28 (t, 2H, J = 7.1, Ar); 7.62 (d, 2H, J = 3.8, C H and C H-pyr);
3 5
N'-(3-Methyl-4-phenylthiazole-2(3H)-ylidene)isonicotinohydra-
zide hydrobromide (3a).
.54 (d, 2H, J = 3.8, C H and C H-pyr); 11.54 (s, 1H, NH, D-
2
6
13
exch.). C-NMR (CDCl ): ꢀ 14.9, 97.0, 120.9, 122.0, 122.3,
3
1
127.2, 128.2, 129.1, 129.8, 129.9, 150.3, 165.0.
H-NMR (DMSO-d ): ꢀ 3.60 (s, 3H, N-CH ); 7.01 (s, 1H,
6
3
C H-thiaz); 7.68-7.79 (m, 5H, Ar); 8.18 (d, 2H, J = 4.9, C H and
5
3
N'-(3-Cyclohexyl-4-methylthiazole-2(3H)-ylidene)isonicotino-
hydrazide hydrochloride (3f).
C H-pyr); 9.05 (d, 2H, J = 4.6, C H and C H-pyr); 12.00 (s, 1H,
5
2
6
13
NH, D-exch.). C-NMR (DMSO-d ): ꢀ 34.7, 98.2, 122.4, 126.4,
6
1
H-NMR (CDCl ): ꢀ 1.14-1.37 (m, 6H, CH ); 1.63-2.09 (m,
1
28.0, 129.3, 129.9, 134.3, 140.9, 144.8, 149.8, 159.6, 163.0.
3
2
4
1
8
H, CH ); 2.22 (s, 3H, CH ); 3.22-3.26 (m, 1H, CH); 6.34 (s,
2 3
N'-(3,4-Diphenylthiazole-2(3H)-ylidene)isonicotinohydrazide
hydrobromide (3c).
H, C H-thiaz); 8.18 (dd, 2H, J = 4.6, 1.3, C H and C H-pyr);
5
3
5
.85 (dd, 2H, J = 4.6, 1.3, C H and C H-pyr); 10.43 (s, 1H, NH,
2
6
13
1
D-exch.). C-NMR (CDCl ): ꢀ 13.25, 24.6, 29.6, 31.3, 59.6,
9
H-NMR (DMSO): ꢀ 6.20 (s, 1H, C H-thiaz); 7.19-7.40 (m,
3
5
7.2, 122.7, 137.1, 140.1, 150.0, 164.5, 166.9.
1
=
0H, Ar); 7.77 (d, 2H, J = 4.2, C H and C H-pyr); 8.68 (d, 2H, J
3 5
4.2, C H and C H-pyr); 11.67 (s, 1H, NH, D-exch.). C-NMR
2 6
1
3
N'-(3-Allyl-4-methylthiazole-2(3H)-ylidene)isonicotinohydra-
zide hydrochloride (3h).
(
DMSO-d ): ꢀ 108.2, 122.2, 122.8, 124.2, 126.4, 128, 128.7,
6
1
29.6, 134.3, 140.9, 141.3, 147.5, 149.8, 154, 168.2.
1
H-NMR (CDCl ): ꢀ 2.13 (s, 3H, CH ); 4.45 (d, 2H, J = 2.5,
3
3
N'-(3-Cyclohexyl-4-phenylthiazole-2(3H)-ylidene)isonicotino-
hydrazide hydrobromide (3e).
N-CH ); 5.03 (dd, 2H, J = 17.2, 10.5, =CH ); 5.66 (s, 1H, C H-
thiaz); 5.83-5.92 (m, 1H, CH=); 7.67 (d, 2H, J = 3.8, C H and
C
NH, D-exch.). C-NMR (CDCl
3
1
2
2
5
3
1
H-NMR (CDCl ): ꢀ 1.11-1.38 (m, 6H, CH ); 1.70-2.17 (m,
5
H-pyr); 8.63 (d, 2H, J = 3.6, C
2
H and C
): ꢀ 16.7, 44.1, 65.3, 100.1,
03.2, 122.7, 135.4, 143.9, 145.89, 165.2, 178.5.
6
H-pyr); 10.56 (s, 1H,
3
2
1
3
4
7
H, CH ); 3.69-3.76 (m, 1H, CH); 5.90 (s, 1H, C H-thiaz); 7.25-
2
5
.46 (m, 5H, Ar); 7.66 (d, 2H, J = 4.6, C H and C H-pyr); 8.70
3
5
(
d, 2H, J = 4.6, C H and C H-pyr); 11.65 (s, 1H, NH, D-exch.).
2 6
Microbiological Assay.
1
3
C-NMR (CDCl ): ꢀ 24.9, 25.9, 28.5, 59.5, 98.2, 120.7, 128.7,
3
1
28.96, 129.3, 132.0, 142.1, 150.0, 160.3, 168.3.
The determination of MIC against Mycobacteria was carried
out by the two-fold agar dilution method [30] in 24-multiwell
plates (Nunc, Naperville, H, USA) using 7H11 agar (Difco
Laboratories) containing the compounds under investigation at
concentrations that ranged between 100 and 0.19 μg/ml, on
which 100 μl of the test bacterial suspension were spotted.
Suspensions to be used for drug susceptibility testing were
prepared from 7H9 broth cultures containing 0.05% Tween 80,
washed, suspended in 0.1% Tween 80-saline to yield a turbidity
no 1 McFarland, and then diluted in saline to obtain inocula of
N'-(3-Allyl-4-phenylthiazole-2(3H)-ylidene)isonicotinohydrazide
hydrobromide (3g).
1
H-NMR (CDCl ): ꢀ 4.48 (t, 2H, J = 5.4, N-CH ); 5.19 (dd,
3
2
2
H, J = 15.74, 10.7, 1.5, =CH ); 5.85-5.90 (m, 1H, CH=); 6.96
2
(s, 1H, C H-thiaz); 7.43-7.61 (m, 5H, Ar); 8.13 (dd, 2H, J = 4.6,
5
1
.5, C H and C H-pyr); 9.07 (dd, 2H, J = 4.6, 1.5, C H and C H-
3 5 2 6
1
3
pyr); 11.78 (s, 1H, NH, D-exch.). C-NMR (CDCl ): ꢀ 48.7,
6
1
3
6.4, 102.0, 118.0, 122.9, 128.8, 129.2, 129.9, 130.6, 134.98,
41.6, 145.9, 146.7, 170.2, 190.2.
5
4
3x10 - 1.5x10 cells/100μl of bacterial suspension. After a 21-
day (slow growers) or 7-day (rapid growers) cultivation in a CO2
General Procedure for the Synthesis of N'-(3,4-disubstitutedthia-
zole-2(3H)-ylidene)isonicotinohydrazides•HCl 3b, 3d, 3f, and 3h.
(
5% CO -95% humidified air) incubator at 37 °C, the growth of
2
organisms was scored. The MIC was defined as the minimum
concentration causing complete growth inhibition of organisms
or allowing no more than five colonies to growth.
A mixture of the appropriate 1-isonicotinoyl-4-substituted-
thiosemicarbazide (4.8 mmol) and 2-chloroacetone (4.8 mmol)