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1.
Several 6‐substituted‐3‐[(5‐mercepto‐1,3,4‐oxadiazol‐2‐yl)methyl]‐2‐substituted quinazolin‐4(3H)‐one or 6‐substituted‐3‐[4‐(5‐mercepto‐1,3,4‐oxadiazol‐2‐yl)phenyl]‐2‐substituedquinazolin‐4(3H)‐one 2(a‐l) and 6‐substituted‐3‐[(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)methyl]‐2‐substitutedquinazolin‐4(3H)‐one or 6‐substi‐tuted‐3‐[4‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl) phenyl]‐2‐substitutedquinazolin‐4(3H)‐one 3(a‐l) were synthesized using conventional and microwave techniques respectively and were screened for antibacterial and antifungal activity.  相似文献   

2.
A variety of novel 3‐propyl‐2‐substitutedamino‐quinazolin‐4(3H)‐ones were synthesized by reacting the amino group of 2‐hydrazino‐3‐propyl quinazolin‐4(3H)‐one with a variety of aldehydes and ketones. The starting material 2‐hydrazino‐3‐propyl quinazolin‐4(3H)‐one was synthesized from propylamine. The title compounds were investigated for analgesic and anti‐inflammatory activities. The compound 2‐(1‐ethylpropylidene‐hydrazino)‐3‐propyl‐quinazolin‐4(3H)‐one ( SR2 ) emerged as the most active compound of the series, and it is more potent in its analgesic and anti‐inflammatory activities when compared with the reference standard diclofenac sodium.  相似文献   

3.
Some novel phosphines, aminophosphines and their oxides, and derived phosphorus acids bearing 4‐oxo ‐ 2‐phenylquinazolin‐3‐yl moiety were synthesized. The methodology depended on the reaction of each 2‐phenylquinazolin‐4(3H)‐one ( 1 ) and 3‐amino‐2‐phenyl‐quinazolin‐4(3H)‐one ( 2 ) with (Ph)2PCl, PhPCl2, and PhP (O)Cl2 in different ratios. The synthesized compounds were characterized by elemental analysis and spectral tools.  相似文献   

4.
The syntheses of nine new 5‐iodosalicylic acid‐based 1,3,4‐oxadiazoline derivatives starting from methyl salicylate are described. These compounds are 2‐[4‐acetyl‐5‐methyl‐5‐(3‐nitrophenyl)‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6a ), 2‐[4‐acetyl‐5‐methyl‐5‐(4‐nitrophenyl)‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6b ), 2‐(4‐acetyl‐5‐methyl‐5‐phenyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl)‐4‐iodophenyl acetate, C19H17IN2O4 ( 6c ), 2‐[4‐acetyl‐5‐(4‐fluorophenyl)‐5‐methyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate, C19H16FIN2O4 ( 6d ), 2‐[4‐acetyl‐5‐(4‐chlorophenyl)‐5‐methyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate, C19H16ClIN2O4 ( 6e ), 2‐[4‐acetyl‐5‐(3‐bromophenyl)‐5‐methyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6f ), 2‐[4‐acetyl‐5‐(4‐bromophenyl)‐5‐methyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6g ), 2‐[4‐acetyl‐5‐methyl‐5‐(4‐methylphenyl)‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6h ) and 2‐[5‐(4‐acetamidophenyl)‐4‐acetyl‐5‐methyl‐4,5‐dihydro‐1,3,4‐oxadiazol‐2‐yl]‐4‐iodophenyl acetate ( 6i ). The compounds were characterized by mass, 1H NMR and 13C NMR spectroscopies. Single‐crystal X‐ray diffraction studies were also carried out for 6c , 6d and 6e . Compounds 6c and 6d are isomorphous, with the 1,3,4‐oxadiazoline ring having an envelope conformation, where the disubstituted C atom is the flap. The packing is determined by C—H…O, C—H…π and I…π interactions. For 6e , the 1,3,4‐oxadiazoline ring is almost planar. In the packing, Cl…π interactions are observed, while the I atom is not involved in short interactions. Compounds 6d , 6e , 6f and 6h show good inhibiting abilities on the human cancer cell lines KB and Hep‐G2, with IC50 values of 0.9–4.5 µM.  相似文献   

5.
The model morpholine‐1‐carbothioic acid (2‐phenyl‐3H‐quinazolin‐4‐ylidene) amide (1) reacts with phenacyl bromides to afford N4‐(5‐aryl‐1,3‐oxathiol‐2‐yliden)‐2‐phenylquinazolin‐4‐amines (4) or N4‐(4,5‐diphenyl‐1,3‐oxathiol‐2‐yliden)‐2‐phenyl‐4‐aminoquinazoline ( 5 ) by a thermodynamically controlled reversible reaction favoring the enolate intermediate, while the 4‐[4‐aryl‐5‐(2‐phenylquinazolin‐4‐yl)‐1,3‐thiazol‐2‐yl]morpholine ( 8 ) was produced by a kinetically controlled reaction favoring the C‐anion intermediate. 1H nmr, 13C nmr, ir, mass spectroscopy and x‐ray identified compounds ( 4 ), ( 5 ) and ( 8 ).  相似文献   

6.
Regioselective reactions of morpholine‐1‐carbothioic acid (2‐phenyl‐3H‐quinazolin‐4‐ylidene) amide ( 1 ) with electrophiles and nucleophiles were studied. The compound ( 1 ) reacts with alkyl halides in basic medium to afford S‐substituted isothiourea derivatives, with amines to give 1,1‐disubstituted‐3‐(2‐phenyl‐3H‐quinazolin‐4‐ylidene) thioureas and l‐substituted‐3‐(2‐phenyl‐quinazolin‐4‐yl) thioureas via transami‐nation reaction. The reaction of ( 1 ) with amines in the presence of H2O2 provided N4‐disubstituted‐N'4‐(2‐phenylquinazolin‐4‐yl)morpholin‐4‐carboximidamide via oxidative desulfurization. Estimation of reactivity sites on ( 1 ) was supported using the ab initio (HF/6‐31G**) quantum chemistry calculations. The ir, 1H nmr, 13C nmr, mass spectroscopy and x‐ray identified the isolated products.  相似文献   

7.
The bifunctional 3/4‐[acetyl]phenylsydnones 1a, 1b were subjected to a one‐pot ring conversion to 3‐[3/4‐acetyl]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 2a, 2b , which on further bromination yielded the 3‐[3/4‐bromoacyl]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 3a, 3b . Reaction of these compounds with thiourea yielded the 3‐[3/4‐(2‐aminothiazol‐4‐yl)]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 4a, 4b . The other thiazole derivatives 5a, 5b–7a, 7b were prepared by using thiosemicarbazide, thioacetamide, and thiobenzamide, respectively. In another reaction of the bromoacetyl compounds ( 3a, 3b ) with 2‐aminopyridine and 2‐aminothiazole, the fused biheterocyclic compounds 3‐[3/4‐imidazo‐[1,2‐a]pyridine‐2‐yl]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 8a, 8b and 3‐[3/4‐imidazo‐[2,1‐b]‐thiazol‐6‐yl]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 9a, 9b were obtained. The 3‐[3/4‐(benzofuran‐2‐carbonyl)]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 10a, 10b were obtained by treatment of compounds 3a, 3b with o‐hydroxy benzaldehyde. Most of these compounds exhibited antifungal activity greater than the reference drugs used. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:50–54, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20255  相似文献   

8.
New series of (thieno[2,3‐c]pyrazolo‐5‐yl)‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazoles 10a , 10b , 10c and (thieno[2,3‐c]pyrazol‐5‐yl)‐1,3,4‐oxadiazol‐3(2H)‐yl)ethanones 6a , 6b , 6c has been synthesized from thieno[2,3‐c]pyrazole‐5‐carbohydrazide 3 by multistep reaction sequence. (5‐Aryl‐1,3,4‐oxadiazol‐2‐yl)‐1H‐thieno[2,3‐c]pyrazoles 4a , 4b , 4c were also synthesized from thieno[2,3‐c]pyrazole‐5‐carbohydrazide 3 by cyclization with various aromatic carboxylic acids. The hydrazide 3 was obtained by reaction of thieno[2,3‐c]pyrazole‐5‐carboxylate 2 with hydrazine hydrate in good yield, and compound 2 was obtained by the reaction of 5‐chloro‐3‐methyl‐1‐phenyl‐1H‐pyrazole‐4‐carbaldehyde 1 and 2‐ethyl thioglycolate in presence of sodium alcoholate in good yield.  相似文献   

9.
A novel class of 3‐(4‐chlorophenyl)‐2‐(substituted)quinazolin‐4(3H)‐one derivatives were synthesized, and the structure of synthesized compounds was characterized by IR, 1H NMR, and mass spectroscopy. The newly synthesized compounds ( 4a–g and 6a–g ) were tested for their in vitro cyclooxygenase (COX) inhibition activity. The compounds have inhibitory profile against both COX‐1 and COX‐2, and some of the compounds are found to be selective against COX‐2. The compound 6g showed distinct inhibitory activity on COXs. The synthesized compounds were evaluated for their potential anti‐inflammatory activity as inhibitors of the proinflammatory cytokines IL‐6. Compounds 4d – g showed the highest level of inhibition among all the tested compounds. Thus, our data suggested that these compounds may represent a new class of potent anti‐inflammatory agents.  相似文献   

10.
The present study emphasizes on the dealklylation of 3‐aryl‐5‐alkyl‐2‐oxo‐Δ4‐1,3,4‐oxadiazoles when reacted with formamide resulting in the formation of 2‐aryl‐2H‐1,2,4‐triazol‐3(4H )‐ones as major product. Subsequent reactions of 2‐aryl‐2H‐1,2,4‐triazol‐3(4H )‐one gave triazolo[3,4‐b ][1,3,4]thiadiazoles and triazolo[3,4‐b ][1,3,4]thiadiazines derivatives incorporated with 1,2,4‐triazol‐3‐one.  相似文献   

11.
The present study depicts synthesis of a series of some novel 5‐(5‐(aryl)‐1,3,4‐oxadiazol‐2‐yl)‐3,4‐dihydro‐6‐methyl‐4‐styrylpyrimidin‐2(1H)‐one derivatives. All the newly synthesized compounds were characterized by FTIR, 1H NMR, 13C NMR, mass spectrometry, and elemental analysis. The compounds were evaluated for their in vivo anti‐inflammatory activity by the carrageenan‐induced rat paw edema method. The compounds were also screened for their anthelmintic activity on Indian earthworms and antibacterial activity against some gram positive and gram negative strains of bacteria. This pharmacological activity evaluation revealed that, among all the compounds screened, compounds 4b and 4c were found to have promising anti‐inflammatory activity. Interestingly, compounds 4b , 4c , and 4i exhibited appreciable anthelmintic property, while compounds 4c , 4g , and 4h showed leading antibacterial activity against the selected pathogenic strains of bacteria.  相似文献   

12.
An efficient and convenient synthesis of a new series of 2‐{(6H‐indolo[2,3‐b]quinoxalin‐6‐yl)methyl}‐5‐aryl‐1,3,4‐oxadiazoles from readily available 1,2‐diaminobenzene and isatins under microwave irradiation conditions was disclosed. The 6‐{(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)methyl}‐6H‐indolo[2,3‐b]quinoxalines were also prepared by the thermal cyclo‐condensation reaction of 2‐(6H‐indolo[2,3‐b]quinoxalin‐6‐yl)acetohydrazides with carboxylic acids in refluxing POCl3. The microwave‐assisted synthesis was rapid and resulted in higher yield of the products at lower operating temperature with reduced waste generation in comparison with the thermal reaction protocol.  相似文献   

13.
A new, simple and general one‐pot method for the preparation of (5‐R‐1,3,4‐oxadiazol‐2‐yl)furoxans has been developed on the basis of the interaction between accessible 3‐methylfuroxan‐4‐carboxylic acid hydrazide and aliphatic, aromatic and heterocyclic carboxylic acids or their chlorides in the presence of POCl3. The synthesis and study of (5‐R‐1,3,4‐oxadiazol‐2‐yl)furoxans reactivity resulted in new polyheterocyclic ensembles incorporating furoxan, 1,3,4‐oxadiazole, pyrrole, triazole, furan, thiophene, pyrimidine, and other heterocycles in different combinations.  相似文献   

14.
Reactions of biacetyl (=butane‐2,3‐dione) with (N‐isocyanimino)triphenylphosphorane in the presence of aromatic carboxylic acids proceed smoothly at room temperature and under neutral conditions to afford 3‐(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)‐3‐hydroxybutan‐2‐one derivatives in high yields.  相似文献   

15.
A new series of 2‐(p‐tolyloxy)‐3‐(5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazol‐2‐yl)quinoline were synthesized from oxidative cyclization of N′‐((2‐(p‐tolyloxy)quinoline‐3‐yl)methylene)isonicotinohydrazide in DMSO/I2 at reflux condition for 3–4 h. The structures of the new compounds were confirmed by elemental analyses as well as IR, 1H‐NMR, and mass spectral data. All the synthesized compounds were screened for their antibacterial activities against various bacterial strains. Several of these compounds showed potential antibacterial activity. J. Heterocyclic Chem., (2011).  相似文献   

16.
The reaction of 3‐N‐(2‐mercapto‐4‐oxo‐4H‐quinazolin‐3‐yl)acetamide ( 1 ) with hydrazine hydrate yielded 3‐amino‐2‐methyl‐3H‐[1,2,4]triazolo[5,1‐b]quinazolin‐9‐one ( 2 ). The reaction of 2 with o‐chlorobenzaldehyde and 2‐hydroxy‐naphthaldehyde gave the corresponding 3‐arylidene amino derivatives 3 and 4 , respectively. Condensation of 2 with 1‐nitroso‐2‐naphthol afforded the corresponding 3‐(2‐hydroxy‐naphthalen‐1‐yl‐diazenyl)‐2‐methyl‐3H‐[1,2,4]triazolo[5,1‐b]quinazolin‐9‐one ( 5 ), which on subsequent reduction by SnCl2 and HCl gave the hydrazino derivative 6. Reaction of 2 with phenyl isothiocyanate in refluxing ethanol yielded thiourea derivative 7. Ring closure of 7 subsequently cyclized on refluxing with phencyl bromide, oxalyl dichloride and chloroacetic acid afforded the corresponding thiazolidine derivatives 8, 9 and 10 , respectively. Reaction of 2‐mercapto‐3‐phenylamino‐3H‐quinazolin‐4‐one ( 11 ) with hydrazine hydrate afforded 2‐hydrazino‐3‐phenylamino‐3H‐quinazolin‐4‐one ( 12 ). The reactivity 12 towards carbon disulphide, acetyl acetone and ethyl acetoacetate gave 13, 14 and 15 , respectively. Condensation of 12 with isatin afforded 2‐[N‐(2‐oxo‐1,2‐dihydroindol‐3‐ylidene)hydrazino]‐3‐phenylamino‐3H‐quinazolin‐4‐one ( 16 ). 2‐(4‐Oxo‐3‐phenylamino‐3,4‐dihydroquinazolin‐2‐ylamino)isoindole‐1,3‐dione ( 17 ) was synthesized by the reaction of 12 with phthalic anhydride. All isolated products were confirmed by their ir, 1H nmr, 13C nmr and mass spectra.  相似文献   

17.
A series of 4‐[2‐(alicyclic‐[1,2,4]oxadiazol‐3‐yl)phenoxy]‐butyric acids were synthesized from N‐hydroxy‐2‐isopropoxy benzamidine in 4 steps with good yields. These [1,2,4]oxadiazoles are novel platelet aggregation inhibitors preventing human platelet aggregation induced by thromboxane derivative U44,619 and adenosine diphosphate. A structure‐activity‐relationship study revealed that the potency for these 5‐oxadiazoles increases with the increase in the ring size of the alicylic rings. Derivative 8f may be useful as a template for the design of more potent anti‐platelet agents.  相似文献   

18.
This study of 3‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)‐2H‐chromen‐2‐one, C17H10N2O3, 1 , and 3‐[5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazol‐2‐yl]‐2H‐chromen‐2‐one, C16H9N3O3, 2 , was performed on the assumption of the potential anticancer activity of the compounds. Three polymorphic structures for 1 and two polymorphic structures for 2 have been studied thoroughly. The strongest intermolecular interaction is stacking of the `head‐to‐head' type in all the studied crystals. The polymorphic structures of 1 differ with respect to the intermolecular interactions between stacked columns. Two of the polymorphs have a columnar or double columnar type of crystal organization, while the third polymorphic structure can be classified as columnar‐layered. The difference between the two structures of 2 is less pronounced. Both crystals can be considered as having very similar arrangements of neighbouring columns. The formation of polymorphic modifications is caused by a subtle balance of very weak intermolecular interactions and packing differences can be identified only using an analysis based on a study of the pairwise interaction energies.  相似文献   

19.
The reaction of 5‐(1‐pyrrolyl)‐4‐methyl‐2‐phenylthieno[2, 3‐d]pyrimidine carbohydrazide 5 with CS2 in the presence of pyridine afforded the 6‐(2, 3‐dihydro‐2‐mercapto‐1, 3, 4‐oxadiazol‐5‐yl)‐4‐methyl‐5‐(1‐pyrrolyl)‐2‐phenylthieno[2, 3‐d]pyrimidine 6 , which reacted with methyl iodide in the presence of sodium methoxide to yield the 6‐(2‐methylthio‐1, 3, 4‐oxadiazol‐5‐yl)‐4‐methyl‐5‐(1‐pyrrolyl)‐2‐phenyl‐thieno[2, 3‐d]pyrimidine 7. The 6‐(2‐substituted‐1, 3, 4‐oxadiazol‐5‐yl)‐2‐phenylthieno[2, 3‐d]pyrimidine derivatives 9, 11 and 13 were obtained by the condensation of 6‐(2‐methylthio‐1, 3, 4‐oxadiazol‐5‐yl)‐2‐phenylthieno[2, 3‐d]pyrimidine 7 with appropriate secondary amines. The structure of the new compounds was substantiated from their IR, UV‐vis spectroscopy, 1H NMR, mass spectra, elemental analysis and X‐ray crystal analysis.  相似文献   

20.
A plethora of non‐steroidal anti‐inflammatory drugs are available in the market with adverse side effects like gastrointestinal irritation, bleeding, and ulceration. Currently, the focus of researcher on the development of better, synergistic molecules by the hybridization of two or more active biomolecule or ligands to develop newer derivative possessing good anti‐inflammatory activity with minimum side effects. In line with this, the present study was designed to synthesize a series of merged pharmacophore contaning1,2,4‐triazoles and substituted benzyl groups via thio linkage. Purity of the derivatives was confirmed by thin‐layer chromatography, combustion analysis, and melting point. Structure of these derivatives was set up by determining infrared spectroscopy, nuclear magnetic resonance spectroscopy, and mass spectroscopy. All the synthesized derivatives were evaluated for their analgesic and anti‐inflammatory activities in mice and rats, respectively. In animal studies, the derivative 3‐(5‐(4‐nitrobenzylthio)‐4H‐1,2,4‐triazol‐3‐yl) pyridine showed more potent analgesic activity, and the derivative 3‐(5‐(2,4‐dimethylbenzylthio)‐4H‐1,2,4‐triazol‐3‐yl) pyridine showed more potent anti‐inflammatory activity as compared with other derivatives. The results of the present study indicate that reaction of pyridine linked 1,2,4‐triazole‐3‐thiol with different substituted benzyl halides to produce merged pharmacophore contaning1,2,4‐triazoles and substituted benzyl groups with potent analgesic and anti‐inflammatory activities. Docking studies were performed by using Argus lab, and all the derivatives exhibited good docking scores between −10 and −12 kcal/mol and were better as compared with standard drugs aspirin and indomethacin against cyclooxygenase‐2. Among all compounds, 3j has shown the maximum docking score and found in agreement to in pharmacological activities.  相似文献   

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