Month 2016
Synthesis of Certain New Thiazole and 1,3,4-Thiadiazole Derivatives via the
Utility of 3-Acetylindole
temperature for 2 h. The solid product was filtered off and
recrystallized from ethanol to afford 3b–d.
Methyl 2-(1-(1H-indol-3-yl)ethylidene)hydrazinecarbodithioate
(75 MHz, DMSO-d6) δ = 14.7, 16.7, 112.4, 116.6, 120.5,
121.2, 122.6, 122.5, 125.0, 126.1, 129.1, 129.8, 130.4,
135.6, 135.9, 152.4, 154.0, 166.0; MS, m/z (%): 388
(M+, 23), 373 (29), 277 (41), 105 (100), 77 (50). Anal.
Calcd for C21H20N6S (388.49): C, 64.92; H, 5.19; N,
21.63. Found: C, 64.74; H, 5.16; N, 21.48%.
(3b).
Yellow solid; 69%; mp 203–205°C; IR (KBr):
ν =3444, 3157 (2NH), 2943 (CH), 1604 (C¼N) cmꢀ1
;
1H NMR (300 MHz, DMSO-d6): δ= 2.43 (3H, s, CH3),
2.51 (3H, s, CH3), 7.13–8.28 (6H, m, Ar–H and NH),
11.88 (1H, s, NH); mass spectrometry (MS) m/z (%): 263
(M+, 30), 220 (50), 176 (63), 100 (72), 86 (100), 56 (93).
Anal. Calcd for C12H13N3S2 (263.38): C, 54.72; H, 4.97;
N, 15.95. Found: C, 54.64; H, 4.86; N, 15.79%.
2-(2-(1-(1H-Indol-3-yl)ethylidene)hydrazinyl)-5-((4-methoxyphenyl)di-
azenyl)-4-methylthiazole (6c). Red solid (67% yield); mp
212–214°C; IR (KBr) ν =3431, 3248 (2NH), 1578
;
(C¼N) cmꢀ1 1H NMR (300MHz, DMSO-d6) δ= 2.56
(s, 3H, CH3), 3.56 (s, 3H, CH3), 3.74 (s, 3H, OCH3),
6.92–8.55 (m, 9H, Ar–H), 10.37 (s, 1H, D2O-exchange-
able NH), 11.73 (s, 1H, D2O-exchangeable NH); 13C
NMR (75 MHz, DMSO-d6) δ =14.37, 16.37, 55.34
(OCH3), 112.45, 114.40, 116.67, 120.50, 121.52, 122.44,
124.62, 125.25, 126.09, 129.73, 135.45, 135.87, 148.03,
154.01, 154.01, 161.32, 166.06; MS, m/z (%): 404 (M+,
32), 359 (44), 225 (59), 105 (100), 77 (71). Anal. Calcd
for C21H20N6OS (404.49): C, 62.36; H, 4.98; N, 20.78.
Found: C, 62.32; H, 4.90; N, 20.59%.
Ethyl 2-(1-(1H-indol-3-yl)ethylidene)hydrazinecarbodithioate
(3c).
Yellow solid; 64%; mp 181–183°C; IR (KBr):
ν =3417, 3126 (2NH), 2912 (CH), 1591 (C¼N) cmꢀ1
;
1H NMR (300 MHz, DMSO-d6): δ = 1.41 (3H, t,
CH3CH2S), 2.51 (3H, s, CH3), 3.40 (2H, q, SCH2CH3),
7.11–8.22 (6H, m, Ar–H and NH), 11.82 (1H, s, NH);
MS m/z (%): 277 (M+, 73), 262 (50), 248 (100), 206
(51), 192 (74), 176 (50), 107 (21). Anal. Calcd for
C13H15N3S2 (277.41): C, 56.28; H, 5.45; N, 15.15. Found:
C, 56.21; H, 5.36; N, 15.04%.
2-(2-(1-(1H-Indol-3-yl)ethylidene)hydrazinyl)-5-((4-bromophenyl)di-
azenyl)-4-methylthiazole (6d). Orange solid (67% yield);
mp 264–265°C (lit mp (21)).
2-(2-(1-(1H-Indol-3-yl)ethylidene)hydrazinyl)-5-((4-chlorophenyl)di-
azenyl)-4-methylthiazole (6e). Orange solid (72% yield);
mp 256–258°C (lit mp (21)).
Benzyl 2-(1-(1H-indol-3-yl)ethylidene)hydrazinecarbodithioate
(3d).
Yellow solid; 65%; mp 170–172°C; IR (KBr):
ν =3419, 3234 (2NH), 2968 (CH), 1604 (C¼N) cmꢀ1
;
1H NMR (300 MHz, DMSO-d6): δ= 2.42 (3H, s, CH3),
4.58 (2H, s, CH2), 7.02–8.48 (10H, m, Ar–H), 11.62
(1H, s, NH), 12.22 (1H, s, NH); MS m/z (%): 339 (M+,
100), 265 (30), 164 (62), 106 (40), 79 (39). Anal. Calcd
for C18H17N3S2 (339.48): C, 63.68; H, 5.05; N, 12.38.
Found: C, 63.47; H, 5.01; N, 12.24%.
2-(2-(1-(1H-Indol-3-yl)ethylidene)hydrazinyl)-4-phenyl-
5-(phenyldiazenyl)thiazole (6f).
Orange solid (68%
yield); mp 243–245°C; IR (KBr) ν= 3412, 3278
(2NH), 1602 (C¼N) cmꢀ1
;
1H NMR (300 MHz,
Synthesis of 4-methyl-2-(2-(1-(5-methyl-1-phenyl-1H-1,2,3-
triazol-4-yl)ethylidene) hydrazinyl)-5-(aryldiazenyl)thiazole
DMSO-d6) δ= 2.59 (s, 3H, CH3), 3.56 (s, 3H, CH3),
7.00–8.29 (m, 15H, Ar–H), 10.60 (s, 1H, D2O-ex-
changeable NH), 11.79 (s, 1H, D2O-exchangeable
NH); 13C NMR (75 MHz, DMSO-d6) δ = 17.3, 107.4,
110.8, 117.2, 119.7, 121.0, 121.3, 126.7, 129.0,
130.3, 131.1, 133.3, 135.8, 136.6, 155.0, 155.3,
171.6; MS, m/z (%): 436 (M+, 53), 380 (75), 202
(100), 178 (57). Anal. Calcd for C25H20N6S
(436.53): C, 68.78; H, 4.62; N, 19.25. Found: C,
68.65; H, 4.64; N, 19.13%.
(6a–h).
A mixture of thiosemicarbazone 3a (0.232 g,
1 mmol) and the appropriate hydrazonoyl halides 4
(1 mmol) in dioxane (20 mL) containing triethylamine
(0.07 mL) was refluxed for 6 h and allowed to cool, and
the solid that formed was filtered off, washed with EtOH,
dried, and recrystallized from dimethylformamide (DMF)
to give the corresponding 1,3,4-thiadiazolines 6a–h. The
products 6a–h together with their physical constants are
listed subsequently.
2-(2-(1-(1H-Indol-3-yl)ethylidene)hydrazinyl)-4-methyl-5-
(phenyldiazenyl)thiazole (6a). Red solid (70% yield); mp
242–244°C (lit mp (21)). 13C NMR (75 MHz,
DMSO-d6) δ= 14.7, 16.7, 112.4, 116.6, 120.2, 121.7,
122.5, 122.6, 125.1, 126.0, 129.3, 129.9, 130.4, 135.7,
135.6, 152.8, 154.0, 166.0.
2-(2-(1-(1H-Indol-3-yl)ethylidene)hydrazinyl)-5-(phenyldiazenyl)-
4-(thiophen-2-yl)thiazole (6g). Orange solid (67% yield);
mp 243–245°C; IR (KBr) ν =3409, 3257 (2NH), 1635
(C¼N) cmꢀ1
;
1H NMR (300MHz, DMSO-d6) δ= 2.63
(s, 3H, CH3), 3.56 (s, 3H, CH3), 7.01–8.57 (m, 13H, Ar–
H), 10.62 (s, 1H, D2O-exchangeable NH), 11.81 (s, 1H,
D2O-exchangeable NH); MS, m/z (%): 442 (M+, 100),
354 (61), 264 (45), 228 (79), 131(48). Anal. Calcd for
C23H18N6S2 (442.56): C, 62.42; H, 4.10; N, 18.99. Found:
C, 62.36; H, 4.06; N, 18.69%.
2-(2-(1-(1H-Indol-3-yl)ethylidene)hydrazinyl)-4-methyl-5-(p-
tolyldiazenyl)thiazole (6b).
Red solid (73% yield); mp
258–260°C; IR (KBr) ν= 3437, 3234 (2NH), 1577
(C¼N) cmꢀ1
;
1H NMR (300 MHz, DMSO-d6) δ = 2.26
2-(2-(1-(1H-Indol-3-yl)ethylidene)hydrazinyl)-4-(naphthalen-2-
(s, 3H, CH3), 2.57 (s, 3H, CH3), 3.56 (s, 3H, CH3), 7.12–
8.53 (m, 9H, Ar–H), 10.42 (s, 1H, D2O-exchangeable
NH), 11.77 (s, 1H, D2O-exchangeable NH); 13C NMR
yl-5-(phenyl diazenyl)thiazole (6h).
Orange solid (60%
yield); mp 267–269°C; IR (KBr) ν = 3415, 3298 (2NH),
;
1614 (C¼N) cmꢀ1 1H NMR (300 MHz, DMSO-d6)
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet