A Simple and Efficient Procedure for Synthesis of Biologically ... - ISCA
A Simple and Efficient Procedure for Synthesis of Biologically ... - ISCA
A Simple and Efficient Procedure for Synthesis of Biologically ... - ISCA
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Research Journal <strong>of</strong> Chemical Sciences Vol. 1 (1) April (2011)<br />
Res.J.Chem.Sci.<br />
<strong>Synthesis</strong> <strong>of</strong> benzoic acid hydrazide (2): A mixture<br />
methyl benzoate (0.01 mole) <strong>and</strong> hydrazine hydrate<br />
(0.5 g, 0.01 mole) was heated <strong>for</strong> 9 hrs. <strong>and</strong> poured<br />
into ice. The product was isolated <strong>and</strong> crystallized<br />
from ethanol.<br />
<strong>Synthesis</strong> <strong>of</strong> potassium-benzoic acid hydrazide<br />
dithiocarbamate (3): A mixture <strong>of</strong> benzoic acid<br />
hydrazide (0.01 mole), KOH (0.84 g, 0.015 mole)<br />
<strong>and</strong> 1.5 ml CS 2 in absolute alcohol was stirred <strong>for</strong> 21<br />
hrs. <strong>and</strong> product was isolated from diethyl ether.<br />
<strong>Synthesis</strong> <strong>of</strong> 4-amino-5-phenyl-4H-1,2,4-triazole-<br />
3-thiol (4): Potassium salt (0.01 mole) was taken in<br />
hydrazine hydrate <strong>and</strong> heated up to the evolution <strong>of</strong><br />
H 2 S gas cussed nearly 5 hrs. in oil bath. The reaction<br />
mixture was poured into crushed ice <strong>and</strong> treated with<br />
glacial Acetic acid .The product was filtered <strong>and</strong><br />
purified by KOH treatment <strong>and</strong> crystallized from<br />
ethanol.<br />
<strong>Synthesis</strong> <strong>of</strong> 3-(phenyl)-6-(4-N-acetylamino<br />
phenyl) [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole (5):<br />
A mixture <strong>of</strong> n-acetyl-p-amino benzoic acid (0.01<br />
mole) <strong>and</strong> 4-amino-5-phenyl-4H-1,2,4-triazole-3-<br />
thiol (0.01 mole) in POCl 3 (25 ml) was refluxed <strong>for</strong><br />
10 hrs. The reaction mixture was poured into crushed<br />
ice <strong>and</strong> thus solid separated out was filtered, washed<br />
with water <strong>and</strong> crystallized from ethanol.<br />
<strong>Synthesis</strong> <strong>of</strong> 3-(phenyl)-6-(4-amino phenyl)<br />
[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole (ATT) (6):<br />
3-(phenyl)-6-(4-N-acetylamino phenyl) [1,2,4]<br />
triazolo[3,4-b][1,3,4]thiadiazole was hydrolysed by<br />
refluxing with 75 ml <strong>of</strong> ethanol containing 15 ml <strong>of</strong><br />
concentrated HCl <strong>for</strong> 4-5 hrs. it was then poured into<br />
ice-cold water <strong>and</strong> finally made just alkaline with<br />
liquid ammonia. The resultant product 3-(phenyl)-6-<br />
(4-amino phenyl) [1,2,4] triazolo [3,4-b] [1,3,4]<br />
thiadiazole (ATT) is filtered <strong>of</strong>f <strong>and</strong> washed with<br />
water <strong>and</strong> air dried. It was then recrystallised from<br />
ethanol.<br />
<strong>Synthesis</strong> <strong>of</strong> Arylidine-[3,6-(diphenyl)-<br />
[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole] (7a-h): A<br />
mixture <strong>of</strong> equimolar amount <strong>of</strong> 3-(phenyl)-6-(4-<br />
amino phenyl) [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole<br />
19<br />
(0.01 mole) <strong>and</strong> various aromatic aldehydes<br />
(0.01mole) in 50 ml acetic acid <strong>and</strong> refluxed <strong>for</strong> about<br />
10-12 hrs. on oil bath. The reaction mixture was<br />
cooled <strong>and</strong> it was poured in to ice water <strong>and</strong> extracted<br />
with ethyl acetate <strong>and</strong> water <strong>and</strong> finally dried over<br />
anhydrous sodium sulfate. The solvent was evaporated<br />
to give the solid product. It was crystallized from ethyl<br />
acetate hexane using decolorizing charcoal to give<br />
various anils<br />
<strong>Synthesis</strong> <strong>of</strong> 3-[(3,6-diphenyl)-[1,2,4]triazolo[3,4-<br />
b][1,3,4]thiadiazole]-2-aryl-thiazolidine-4-ones (8ah):<br />
A mixture <strong>of</strong> Schiff bases (7a-h) (0.01 mole ) in<br />
THF (30 ml) <strong>and</strong> mercapto acetic acid (thioglycolic<br />
acid) (0.01 mole) with a pinch <strong>of</strong> anhydrous ZnCl 2<br />
was refluxed <strong>for</strong> 12 hours. The solvent was then<br />
removed to get a residue, which was dissolved in<br />
benzene <strong>and</strong> passed through column <strong>of</strong> silica gel using<br />
benzene : chloro<strong>for</strong>m (8:2;v/v) mixture as eluent. The<br />
eluate was concentrated <strong>and</strong> the product crystallized<br />
from alcohol to give 4-thiazolidinones(8a-h).<br />
Spectral Analysis <strong>of</strong> Synthesized compounds (8ah)<br />
(1) 3-[(3,6-diphenyl)-[1,2,4]triazolo[3,4-b][1,3,4]-<br />
thiadiazole]-2-phenyl-thiazolidin-4-one (8a): I.R.<br />
(KBr, cm-1): 3030, 1500 (aromatic C-H), 1600, 1680<br />
(C=O <strong>of</strong> thiazolidinone). PMR (δ ppm): 6.12-7.8 (m,<br />
aromatic), 3.1 (2H <strong>of</strong> CH 2 <strong>for</strong> thiazolidinone), 5.35<br />
(H <strong>of</strong> C 2 H <strong>for</strong> thiazolidinone). 13 CMR (δ ppm): 113-<br />
130 (benzene),136-145 (triazolo-thiadiazole), 169<br />
(C=O), 36 (CH 2 ), 46 (CH).<br />
(2) 3-[(3,6-diphenyl)-[1,2,4]triazolo[3,4-b][1,3,4]-<br />
thiadiazole]-2-(4-methoxyphenyl)-thiazolidin-4-<br />
one (8b): I.R. (KBr, cm-1): 3030, 1500 (aromatic C-<br />
H), 1600, 1690 (pyridine ring, C=O <strong>of</strong><br />
thiazolidinone), 1200 (Ar-O-CH 3 ). PMR (δ ppm):<br />
6.12-7.8 (m, aromatic), 3.2 (2H <strong>of</strong> CH 2 <strong>for</strong><br />
thiazolidinone), 5.35 (H <strong>of</strong> C 2 H <strong>for</strong> thiazolidinone),<br />
3.35 (3H <strong>of</strong> CH 3 <strong>of</strong> thiazolidinone). 13 CMR (δ ppm):<br />
113-131 (benzene),135-145 (triazolo-thiadiazole),<br />
169 (C=O), 36 (CH 2 ), 46 (CH), 56 (CH 3 ).<br />
(3) 3-[(3,6-diphenyl)-[1,2,4]triazolo[3,4-<br />
b][1,3,4]-thiadiazole]-2-(4-hydroxyphenyl)-<br />
thiazolidin-4-one (8c): I.R. (KBr, cm-1): 3030,