Synthesis of New Heterocyclic Derivatives from 4-(3, 5-Dimethyl-1-phenyl-1H-pyrazol-4-ylazo)- benzoic acid

In this work pyrazolin derivatives were prepared from the diazonium chloride salt of 4-aminobenzoic acid. Azo compounds were prepared from the reaction of an ethanolic solution of sodium acetate and calculated amount of active methylene compound namely, acetyl acetone to obtain the corresponding hydrazono derivative (1). Cyclocondensation reaction of compounds (1) with hydrazine hydrate and phenyl hydrazine in boiling ethanol affording the corresponding pyrazoline-5-one derivatives of 4-aminobenzoic acid (2,3). Then compound (3) was reacted with thionyl chloride to give the corresponding acid chloride derivative(4), followed by conversion into the corresponding acid hydrazide derivative (5) carboxylic acid thiosemicarbazide (11), esters (14,15), thioesters (16,17) and amides (18,19), when treated hydrazine hydrate, thiosemicarbazide, alcohols, alkylthiol and secondary amines in dry refluxing benzene; respectively. Schiff's bases (6-8) were prepared by refluxing of compound (5) with different aldehydes and ketons, then two compounds from the Schiff's bases were cyclized with ?-mercapto acetic acid to give (9 and 10). Furthermore, 1,2,4-triazole derivative (12) have been also prepared by refluxing thiosemicarbazide derivative with sodium hydroxide solution (4%) followed acidification of the result using (10%)hydrolic acid. Moreover, a thiadiazole derivative (13) has been prepared by treatment of thiosemicarbazide derivative with concentrated sulfuric acid as cyclyzing agent. Finally, oxadiazole derivative (20) has prepared by condensation of its acid hydrazide derivative with carbon disulfide in basic medium.

Download Full-text

Synthesis and Mesomorphic Properties of Azo Compounds Derived from Phenyl-and Thienyl-1,3,4-Thiadiazole

Zeitschrift für Naturforschung B ◽

10.1515/znb-1997-1215 ◽

1997 ◽

Vol 52 (12) ◽

pp. 1533-1538 ◽

Cited By ~ 21

Author(s):

M. Parra ◽

Sh. Villouta ◽

V. Vera ◽

J. Belmar ◽

C. Zúñiga ◽

...

Keyword(s):

Liquid Crystals ◽

Azo Compounds ◽

Schiff’S Bases ◽

Smectic C ◽

Schiff's Bases ◽

Nematic Mesophase ◽

Central Bond ◽

Imine Bond ◽

Mesomorphic Properties

The synthesis and mesomorphic behaviour of new series of liquid crystals containing 1,3,4- thiadiazole and thiophene rings with azo central bond are reported (series 5a and 5b). All compounds of series 5a exhibit enantiotropic nematic mesophase and the higher homologues (n = 9 - 10) also show a monotropic smectic C phase. Series 5b show dimorphism SC - N (for n = 5 - 7 the SC is monotropic). These series are compared with the Schiff’s bases analogues, the imine bond gives rise to similar liquid crystals phase but larger mesomorphic range.

Download Full-text

Green route synthesis of Schiff's bases of isonicotinic acid hydrazide

Green Chemistry Letters and Reviews ◽

10.1080/17518250902922798 ◽

2009 ◽

Vol 2 (1) ◽

pp. 23-27 ◽

Cited By ~ 10

Author(s):

A.B. Thomas ◽

P.N. Tupe ◽

R.V. Badhe ◽

R.K. Nanda ◽

L.P. Kothapalli ◽

...

Keyword(s):

Isonicotinic Acid ◽

Acid Hydrazide ◽

Isonicotinic Acid Hydrazide ◽

Schiff’S Bases ◽

Schiff's Bases ◽

Green Route

Download Full-text

Synthesis and biological evaluation of new aryl substituted Schiff’s bases

Pharmaceutical and Biological Evaluations ◽

10.26510/2394-0859.pbe.2017.39 ◽

2017 ◽

Vol 4 (6) ◽

pp. 252

Author(s):

Versha Parcha ◽

Jaswinder Kaur

Keyword(s):

Antimicrobial Agents ◽

Acid Hydrazide ◽

Structure Activity Relationship ◽

Biological Evaluation ◽

Activity Relationship ◽

Spectral Studies ◽

Schiff’S Bases ◽

Structure Activity ◽

Schiff's Bases ◽

Good Potential

Objective: Chemical substances employed to treat various infections caused by various types of microorganism are termed as antimicrobials and natural chemical compounds produced by specific types of bacteria are termed as antibiotics. Unlimited use of antibiotics in humans and animals and in areas other than the treatment and prophylaxis of disease have resulted in a serious problem of drug resistance. Various attempts have been adopted to cope with the resistance problem and enhance the activity, or broaden the spectrum of drugs. Based on structure-activity relationship synthesis of new compounds has been one of the best approaches for better results. It has been demonstrated that Schiff base of some leading molecules and antibiotics possess good potential as more effective and safe drugs. Encouraged by reports on potential of Schiff’s bases as antimicrobial agents and to cope up with the current requirements of developing newer, safer and broad spectrum agents attempts were made to synthesize new Schiff’s bases.Methods: Our earlier in which structure activity relationship studies revealed that substitution by nitro and amino gp in Schiff’s base moiety resulted in the enhancement of activity. So further attempts were made to extend the series with incorporation of nitro and amino moiety by condensing o,m dinitro substituted acid hydrazide with various nitro/amino substituted benzaldehydes for increasing their antimicrobial potential.Results: Synthesized compounds were characterized on the basis of spectral studies (like UV, IR, and NMR). All the synthesized derivatives were screened further for their antibacterial effect. All the synthesized derivatives were screened further for their antibacterial effect.Conclusions: Highest activity was observed in the derivative with nitro substitution in both the aryl rings.

Download Full-text

Synthesis, antimicrobial and cytotoxic activities of novel 4-trifluoromethyl-(1,2,3)-thiadiazolo-5-carboxylic acid hydrazide Schiff’s bases

Medicinal Chemistry Research ◽

10.1007/s00044-012-0168-x ◽

2012 ◽

Vol 22 (4) ◽

pp. 1747-1755 ◽

Cited By ~ 5

Author(s):

P. Sambasiva Rao ◽

C. Kurumurthy ◽

B. Veeraswamy ◽

G. Santhosh kumar ◽

B. Narsaiah ◽

...

Keyword(s):

Carboxylic Acid ◽

Acid Hydrazide ◽

Cytotoxic Activities ◽

Schiff’S Bases ◽

Schiff's Bases ◽

Carboxylic Acid Hydrazide

Download Full-text

Synthesis and Antimicrobial Activity of Some 1-arylideneamino-4-(4-chlorobenzylidene)-2-methyl- 1H-imidazolin-5(4H)-one Compounds

Oriental Journal Of Chemistry ◽

10.13005/ojc/350245 ◽

2019 ◽

Vol 35 (2) ◽

pp. 822-828

Author(s):

Cong Tien Nguyen ◽

Dao Thi Hong Dinh ◽

Thin Van Nguyen ◽

Giang Duc Le ◽

Hien Cao Nguyen

Keyword(s):

Antimicrobial Activity ◽

Hydrazine Hydrate ◽

Spectral Data ◽

1H Nmr ◽

Aromatic Aldehydes ◽

Antimicrobial Activities ◽

Gram Negative Bacteria ◽

Schiff’S Bases ◽

Gram Negative ◽

Schiff's Bases

4-Chlorobenzylidene-2-methyl-(4H)-oxazol-5-one, which were prepared from 4-chlorobenzaldehyde and acetylglycine in reaction with hydrazine hydrate in ethanol gave 1-amino-4-(4-chlorobenzylidene)-2-methyl-1H-imidazolin-5(4H)-one. However, treatment of 4-chlorobenzylidene-2-methyl-(4H)-oxazol-5-one with hydrazine hydrate in pyridine yielded 3-(4-chlorophenyl)propanohydrazide. Reaction of 1-amino-4-(4-chlorobenzylidene)-2-methyl-1H-imidazolin-5(4H)-one with aromatic aldehydes gave eight corresponding Schiff’s bases namely 1-arylideneamino-4-(4-chlorobenzylidene)-2-methyl-1H-imidazolin-5(4H)-ones. The structure of the 3-(4-chlorophenyl)propanohydrazide and the imidazoline-5-one compounds was confirmed by IR, 1H-NMR and MS spectral data. The Schiff’s bases were tested for antimicrobial activities against several strains of Gram-positive, Gram-negative bacteria, molds and yeasts.

Download Full-text

Synthesis of Schiff’s Bases of 1,2,4-Triazole Derivatives under Microwave Irradiation Technique and Evaluation of Their Anti-diabetic Activity

Current Microwave Chemistry ◽

10.2174/2213335608666210930201144 ◽

2021 ◽

Vol 08 ◽

Author(s):

Krishna Chandra Panda ◽

B.V.V Ravi Kumar ◽

Biswa Mohan Sahoo

Keyword(s):

Hydrazine Hydrate ◽

Carbon Disulphide ◽

Potassium Hydroxide Solution ◽

Ring Closure ◽

Biologically Active ◽

Schiff’S Bases ◽

Standard Drug ◽

Triazole Derivatives ◽

Schiff's Bases

Background: Schiff bases play key role for the generation of a large number of biologically active compounds via cycloaddition, replacement and ring closure reactions. Objective: The objective of this study is to optimize the purity and yield of product, reaction time, eco-friendly reaction by the help of microwave assisted organic synthesis. Methods: New series of Schiff’s bases of triazole derivatives were achieved via multicomponent reactions. The starting material benzohydrazide 1 was obtained by esterification of bezoyl chloride with methanol in presence of concentrated sulphuric acid followed by the reaction with hydrazine hydrate. Benzohydrazide was allowed to react with carbon disulphide in ethanolic potassium hydroxide solution to yield potassium dithiocarbazinate 2 which undergoes cyclization by reacting with hydrazine hydrate to afford 4-[amino]-5-phenyl-4H-1,2,4-triazole-3-thiol (3). Further, various Schiff’s bases 4a-f were obtained by reacting 1,2,4-triazole-3-thiol with different substituted benzaldehydes under microwave irradiations as a green and eco-friendly energy source. Results: The structures of the newly synthesized compounds were elucidated in accordance with their spectral data and elemental analysis. Conclusion : The obtained compounds exhibited significant in-vivo anti-diabetic activity as compared to the standard drug Metformin. The anti-diabetic effect was investigated by using Alloxan-induced diabetic model.

Download Full-text

Viscoelastic properties of a homologous series of nematic liquid crystalline Schiff's bases

Journal de Physique ◽

10.1051/jphys:019840045080134700 ◽

1984 ◽

Vol 45 (8) ◽

pp. 1347-1360 ◽

Cited By ~ 13

Author(s):

J.P. van der Meulen ◽

R.J.J. Zijlstra

Keyword(s):

Homologous Series ◽

Viscoelastic Properties ◽

Liquid Crystalline ◽

Schiff’S Bases ◽

Schiff's Bases

Download Full-text

Green Synthesis, Characterization, DPPH and Ferrous Ion-chelating (FIC) Activity of Tetrakis-Schiff’s Bases of Terephthalaldehyde

Letters in Drug Design & Discovery ◽

10.2174/1570180815666180531101404 ◽

2019 ◽

Vol 16 (3) ◽

pp. 249-255

Author(s):

Momin Khan ◽

Umar Ali ◽

Anis Ur Rahman ◽

Muhammad Ibrahim ◽

Abdul Hameed ◽

...

Keyword(s):

Antioxidant Activities ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Aromatic Aldehydes ◽

Ferrous Ion ◽

Future Research ◽

Scavenging Activity ◽

Schiff’S Bases ◽

Schiff's Bases ◽

Antioxidant Agents

Background: The role of small molecules as antioxidants to prevent the oxidation of other molecules and inhibit them from radical formation is the area of much interest to cure disease especially cancer. Moreover, the antioxidants play important role as stabilizers to prevent oxidation of fuels and lubricants. Methods: In the present study, fifteen tetrakis-Schiff’s bases derivatives (1-15) were synthesized and screened for their antioxidant activities. Compounds 1-15 were synthesized by continuous stirring of reaction mixture of 1,4-bis (hydrazonomethyl)benzene (1 mmol) with various substituted aromatic aldehydes (2 mmol) in distilled water using acetic acid as catalyst at room temperature for 2-10 min. Results: Our present study showed that all compounds are better ferrous ion-chelating agents except compound 1,4-bis((E)-((E)-(3,4-dimethoxybenzylidene)hydrazono)methyl)benzene (6) (IC50 = 329.26 ± 4.75 µM) which has slightly low activity than the standard EDTA (IC50 = 318.40 ± 5.53 μM). In addition, DPPH radical scavenging activity of eleven compounds showed higher activity than the standard. However, remaining four compounds showed comparable radical scavenging activity to the standard DPPH (IC50 = 257.77 ± 4.60 µM). Conclusion: The series of fifteen Schiff’s bases (1-15) were synthesized and evaluated as antioxidants. From both assays, it has been demonstrated that most of the tetrakis-Schiff’s bases have potential to serve as leads for the development of antioxidant agents for future research.

Download Full-text