Synthesis of some Schiff's bases derivatives from aminoazo compounds

Reaction of,2- [( 4- amio phenyl ) diazenyl] 1,3,4- thiadiazole -5- thiol (S1) with p- chlorobenzeldehyde,3,4 – dimethoxy benzaldehyde and pyrrol-2- carbonxaldehyde gave -5- [{4-(4-chlorobenzylidene amino) phenyl} diezenyl]-1,3,4- thiadiazole-2- thiol (S2),5-[{ 4-[(3,4- dimethoxybenzyldene )amino phenyl ] diazenyl)-1,3,4- thiadiazole-2-thiol,(S3) and -5- [4-(1,H – pyrrol -2- yl- methylene)amino phenyl] diazenyl)-1,3,4- thiadiazole-2- thiol (S4) respectively as schiff's bases compounds. On the same route-2-[(4-amino-1- naphthyl ) diazenyl] -1,3,4- thiadiazole -5- thiol (S5) reacts with –p- chloro benzaldehyde and –m- nitrobenzaldehyde to give the follwing schiff's bases -5-[{ 4-(4- chloro benzylidene ) amino -1- naphthyl} diazenyl] -1,3,4- thiadiazole -2- thiol (S6) and -5- ({ 4- [3- nitrobenzylidene) amino] -1- naphthyl({ diazenyl) -1,3,4 – thiadiazole-2- thiol (S7). Sn2 reaction was carried out by the reaction of compound (S6,S7) with bromo ethyl acetate to get ethyl[5{4-(4- chlorobenzylidene amino)-1- naphthyl} diazenyl] -1- 1,3,4- thiadiazole-2- yl- thio] acetate (S8) and ethyl [5-{4- (2- nitrobenzylidene amino)-1- naphthyl diazenyl] -1,3,4- thiadiazole -2-yl-acetate (S9).(Fig.1)

Synthesis and Characterization of Five, Sevene Heterocyclic Membered Rings

New compounds containing heterocyclic units have been synthesized. These compounds include 2-amino 5- phenyl-1,3,4-thiadiazole (1) as starting material to prepare the Schiff bases 2N[3-nitrobenzylidene -2 hydroxy benzylidene and 4-N,N-dimethyl aminobenzylidene] -5-phenyl-1,3,4-thiadiazole (2abc) , 2N[3-nitrophenyl, 2-hydroxyphenyl or 4-N,N-dimethylaminophenyl] 3-]2-amino-5-phenyl-1,3,4-thiadiazole]-2,3-dihydro-[1,3]oxazepine-benzo-4,7-dione] (3abc), 2N[3-nitrophenyl,2-hydroxyphenyl,4-N,N-dimethylaminophenyl]-3-[2-amino-5-phenyl-1,3,4-thiadiazole-2-yl]-2,3-dihydro-[1,3]oxazepine-4,7-dione[(4abc), 2-N-[3-nitrophenyl, 2-hydroxyphenyl or 4-N,N-dimethylaminophenyl]-3-[2-amino-5-phenyl-1,3,4-thiadiazole-2yl]-1,2,3-trihydro-benzo-[1,2-e][1,3] diazepine-4,7-dione (5abc) ,2N[2-(3-nitrophenyl,2-hydroxyphenyl or 4-N,N-dimethylaminophenyl)]-4-oxo-1,3-thiazolidine-3-yl]-2-amino-5-phenyl-1,3,4-thiadiazole (6abc), 2-N-[5-(3-nitrophenyl,2-hydroxyphenyl or 4-N,N-dimethylaminophenyl)-tetrazolo-1-yl]-2-amino-5-phenyl-1,3,4-thiadiazole (7abc) , 2-N-[5-(3-nitrophenyl,2-hydroxyphenyl or 4-N,N-dimethylaminophenyl)-3-[2-amino-5-phenyl-1,3,4-thiadiazole-2-yl]-2,3-dihydro-[1,3]oxazepine-benzo-4,7-dithione (8abc) , 2-N-[5-(3-nitrophenyl,2-hydroxyphenyl or 4-N,N-dimethylaminophenyl)-3-[2-amino-5-phenyl-1,3,4-thiadiazole-2-yl]-2,3-dihydro-[1,3]oxazepine -4,7-dithione -5-ene (9abc) and 2-N-[5-(3-nitrophenyl,2-hydroxyphenyl or 4-N,N-dimethylaminophenyl)-3-[2-amino-5-phenyl-1,3,4-thiadiazole-2-yl] -1,2,3-trihydro-benzo-[1,2-e][1,3] diazepine -4,7-dithione - (10abc) . the structures of these compounds were characterized by FT-IR, 1H,13C-NMR,Uv/vis spectroscopy and the melting points were determined besides the evaluation of its biological activity

Preparation of some azo compounds by diazotization and coupling of 2- amino -5 – thiol -1,3,4- thiadizaole

2- amino -5- thiol-1,3,4- thiadiazole (S1) was prepared by cyclic locking of thiosemicarbazide in the presence of anhydrous sodium carbonate and CS2. diazotization of (S1) compound gave diazonium salt (S2) that reacts with different activated aromatic compounds to get the following azo compounds ,2 [(4- aminophenyl) diazenyl ] 1,3,4- thiazdiazole-5- thiol (S3) ,2-[4-amino- 1-naphthyl diazenyl] -1,3,4 – thiazdiazole-5-thiol (S4) , 3-amino-4-[(5- mercapto -1,3,4- thiadiazole -2-yl) diazenyl ] phenol(S5) ,1-[(5-mercapto-1,3,4-thiadiazole-2-yl) diazenyl] -2-naphthol (S6) , 5-{[4-(dimethylamino) phenyl] diazenyl}-1,3,4-thiadiazole-2- thiol(S7) ,5-{[4-(diethylamino) phenyl] diazenyl}-1,3,4- thiadiazole-2- thiol(S8) ,2- amino-5-[(5-mercapto-1,3,4-thiadiazole-2-yl) diazenyl] phenol(S9) . All the prepared azo compounds have been characterized and identified through the study of their some physical, chemical and spectrometrical (U.V.I.R) properties

Corrosion Inhibition of Thiourea and Thiadiazole Derivatives : A Review

The continuous search for better corrosion inhibitors, due to vast differences in the media encountered in industry remains a focal point in corrosion control. The use of organic compounds to inhibit corrosion has assumed great significance due to their application in preventing corrosion under various corrosive environments. These compounds have great potential to inhibit aqueous corrosion due to film formation by adsorption on the metal surface. This paper reviews the inhibitive effect of thiourea and thiadiazole derivatives. This group of organosulphur and heterocyclic compounds and derivatives has important theoretical and practical applications, but their inhibition mechanism is not fully understood, despite extensive study. The effect of these compounds on the corrosion of metallic alloys was evaluated through assessment of various journals and experimental techniques. The corrosion rate was found to be a function of different variables. Due attention was paid to the systematic study of inhibitor action of derivatives with much emphasis on the functional groups of the molecular structure. From the comprehensive discourse presented, it is concluded that the derivatives fulfill the basic requirements for consideration as an efficient corrosion inhibito

Acetazolamide-based fungal chitinase inhibitors

Chitin is an essential structural component of the fungal cell wall. Chitinases are thought to be important for fungal cell wall remodelling, and inhibition of these enzymes has been proposed as a potential strategy for development of novel anti-fungals. The fungal pathogen Aspergillus fumigatus possesses two distinct multi-gene chitinase families. Here we explore acetazolamide as a chemical scaffold for the inhibition of an A. fumigatus ‘plant-type’ chitinase. A co-crystal structure of AfChiA1 with acetazolamide was used to guide synthesis and screening of acetazolamide analogues that yielded SAR in agreement with these structural data. Although acetazolamide and its analogues are weak inhibitors of the enzyme, they have a high ligand efficiency and as such are interesting leads for future inhibitor development

In vitro assessment of antimicrobial, antioxidant, and cytotoxic properties of Saccharin-Tetrazolyl and-Thiadiazolyl derivatives: the simple dependence of the pH value on antimicrobial activity

The antimicrobial, antioxidant, and cytotoxic activities of a series of saccharin-tetrazolyl and -thiadiazolyl analogs were examined. The assessment of the antimicrobial properties of the referred-to molecules was completed through an evaluation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against Gram-positive and Gram-negative bacteria and yeasts. Scrutiny of the MIC and MBC values of the compounds at pH 4.0, 7.0, and 9.0 against four Gram-positive strains revealed high values for both the MIC and MBC at pH 4.0 (ranging from 0.98 to 125 µg/mL) and moderate values at pH 7.0 and 9.0, exposing strong antimicrobial activities in an acidic medium. An antioxidant activity analysis of the molecules was performed by using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, which showed high activity for the TSMT (N-(1-methyl-2H-tetrazol-5-yl)-N-(1,1-dioxo-1,2-benzisothiazol-3-yl) amine, 7) derivative (90.29% compared to a butylated hydroxytoluene positive control of 61.96%). Besides, the general toxicity of the saccharin analogs was evaluated in an Artemia salina model, which displayed insignificant toxicity values. In turn, upon an assessment of cell viability, all of the compounds were found to be nontoxic in range concentrations of 0-100 µg/mL in H7PX glioma cells. The tested molecules have inspiring antimicrobial and antioxidant properties that represent potential core structures in the design of new drugs for the treatment of infectious diseases.Funding Agency Portuguese Foundation for Science and Technology UID/QUI/00100/2019 UID/MULTI/04326/2019 -CCMAR Portuguese Foundation for Science and Technology SFRH/BPD/99851/2014 IST-ID/115/2018info:eu-repo/semantics/publishedVersio

Synthesis of some Schiff's bases derivatives from aminoazo compounds

Reaction of,2- [( 4- amio phenyl ) diazenyl] 1,3,4- thiadiazole -5- thiol (S1) with p- chlorobenzeldehyde,3,4 – dimethoxy benzaldehyde and pyrrol-2- carbonxaldehyde gave -5- [{4-(4-chlorobenzylidene amino) phenyl} diezenyl]-1,3,4- thiadiazole-2- thiol (S2),5-[{ 4-[(3,4- dimethoxybenzyldene )amino phenyl ] diazenyl)-1,3,4- thiadiazole-2-thiol,(S3) and -5- [4-(1,H – pyrrol -2- yl- methylene)amino phenyl] diazenyl)-1,3,4- thiadiazole-2- thiol (S4) respectively as schiff's bases compounds. On the same route-2-[(4-amino-1- naphthyl ) diazenyl] -1,3,4- thiadiazole -5- thiol (S5) reacts with –p- chloro benzaldehyde and –m- nitrobenzaldehyde to give the follwing schiff's bases -5-[{ 4-(4- chloro benzylidene ) amino -1- naphthyl} diazenyl] -1,3,4- thiadiazole -2- thiol (S6) and -5- ({ 4- [3- nitrobenzylidene) amino] -1- naphthyl({ diazenyl) -1,3,4 – thiadiazole-2- thiol (S7). Sn2 reaction was carried out by the reaction of compound (S6,S7) with bromo ethyl acetate to get ethyl[5{4-(4- chlorobenzylidene amino)-1- naphthyl} diazenyl] -1- 1,3,4- thiadiazole-2- yl- thio] acetate (S8) and ethyl [5-{4- (2- nitrobenzylidene amino)-1- naphthyl diazenyl] -1,3,4- thiadiazole -2-yl-acetate (S9).(Fig.1)

Synthesis, spectroscopic and crystal structure analysis of a compound with pharmocophoric substituent: 2-cyclohexyl-6-(2-oxo-2H-chromen-3-yl)- imidazo[2,1-b] [1,3,4]thiadiazole-5-carbaldehyde

Imidazo[2,1-b][1,3,4] thiadiazole derivatives are significant for their various pharmacological properties. This paper reports the synthesis and structure of one of them, 2-cyclohexyl-6-(2-oxo-2H-chromen-3-yl)imidazo[2,1-b][1,3,4]thiadiazole-5-carbaldehyde. The compound crystallizes in the monoclinic space group P21/c with a=17.316(3)Å, b=6.5420(9)Å, c =17.056(3)Å, β=112.909(2)°, V=1779.7(4)Å3, z=4. The, Imidazo[2,1-b][1,3,4] thiadiazole and the coumarin ring systems are each planar but inclined at an angle of 48.14(2)° towards each other. The crystal structure is stabilized by C–H … O interactions

Preparation of some azo compounds by diazotization and coupling of 2- amino -5 – thiol -1,3,4- thiadizaole

2- amino -5- thiol-1,3,4- thiadiazole (S1) was prepared by cyclic locking of thiosemicarbazide in the presence of anhydrous sodium carbonate and CS2. diazotization of (S1) compound gave diazonium salt (S2) that reacts with different activated aromatic compounds to get the following azo compounds ,2 [(4- aminophenyl) diazenyl ] 1,3,4- thiazdiazole-5- thiol (S3) ,2-[4-amino- 1-naphthyl diazenyl] -1,3,4 – thiazdiazole-5-thiol (S4) , 3-amino-4-[(5- mercapto -1,3,4- thiadiazole -2-yl) diazenyl ] phenol(S5) ,1-[(5-mercapto-1,3,4-thiadiazole-2-yl) diazenyl] -2-naphthol (S6) , 5-{[4-(dimethylamino) phenyl] diazenyl}-1,3,4-thiadiazole-2- thiol(S7) ,5-{[4-(diethylamino) phenyl] diazenyl}-1,3,4- thiadiazole-2- thiol(S8) ,2- amino-5-[(5-mercapto-1,3,4-thiadiazole-2-yl) diazenyl] phenol(S9) . All the prepared azo compounds have been characterized and identified through the study of their some physical, chemical and spectrometrical (U.V.I.R) properties