Synthesis of new 4 3hquinazolinone derivatives under solventfree conditions using peg400 palle v. There are two structural isomers, 2 quinazolinone and 4 quinazolinone, with the 4 isomer being the more common. Article views are the countercompliant sum of full text article downloads since november 2008 both pdf and html across all institutions and individuals. Unlike other classes of isomers, tautomeric compounds exist in mobile. Synthesis, tautomeric structure and antimicrobial activity of 3arylhydrazono 4 phenyl1,2, 4 triazepino2,3aquinazoline2,71hdi ones. Pdf synthesis, tautomeric structure and antimicrobial activity of 3. Tautomeric equilibria of 2 and 4 thiouracil in gas phase and in solvent. Chem 315316 ketoenol tautomer handout beauchamp 1 z. Synchronous and asynchronous double proton transfer in cyclic hydrogenbonded associates, russian chemical bulletin on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Synthesis, tautomeric structure and antimicrobial activity. Malaria is a neglected tropical parasitic disease affecting billons of people around the globe. Synthesis of an activatable tetrasubstituted nickel. It was used in the synthesis of 4 quinazolinone derivatives, inhibitors of the.
The antihyperlipidemic activities of 43h quinazolinone. Ketoenol equilibrium in quinolin 4 one and atom numbers. Theoretical study by density functional theory method dft. Synthesis of new 43hquinazolinone derivatives using 54h oxazolones article pdf available in molecules 115. N n quinazoline n h n o 21h quinazolinone n nh o 4 3h quinazolinone n h nh o o 4 1h,3hquinazolinedione s gabriel in.
The most common type of tautomerism is that involving carbonyl, or keto, compounds and unsaturated hydroxyl compounds, or enols. The new quinazolinone derivatives were evaluated for their anticonvulsant activity according to the anticonvulsant drug development add program protocol. It turns out that ketones and aldehydes often exist in rapid equilibrium with a tautomeric form known as an enol the alphaprotons of carbonyls, as you recall, are somewhat acidic. To a solution of 3amino2methyl 4 3h quina zolinone 5 mmol in methanol 20 ml, required aromatic aldehyde 5 mmol was added and the reaction mixture was then stirred for about 3 4 h and refluxed over night. Intramolecular alkyl rearrangements and tautomerism of quinazolinone derivatives author links open overlay panel y. Quinazolinone and quinazoline derivatives semantic scholar. Read tautomerism of quinazolin 4 ones with 2,3annulated hydrogenated 1,3diazaheterocycles. Synthesis and antimicrobial evaluation of novel 2chloromethyl3 4 methyl6oxo5e phenyldiazenyl 2 thioxo 5,6 dihydropyrimidine 12h ylquinazoline 4 3hones derivatives were carried out by kumar and coworkers fig. This tautomericinteraction can also be observed when a 43hquinazolinone containing a methyl in the 3position is subjected to chlorination with pocl3, the. Structures of tautomers of quinoline 4 one studied derivatives. It was further simplify that 4 hydroxyquinazoline xi and 4 quinazoline or 4 3 quinazoline xii is a tautomeric mixture of the lactum and the lactim form. Printed ra grttt britair intramolecular rearrangementv. There are two equilibria taking place, namely keto1enol and enol2aenol2b.
Intramolecular alkyl rearrangements and tautomerism of quinazolinone. Pdf quinazoline, a heterocyclic compound, has been extensively studied and used. The tautomerism of organic compounds has been the subject of extensive theoretical. Pdf on the tautomerism of 2,4disubstituted 3,4,5,6. Paper 2679 efficient coppercatalyzed synthesis of 2amino 4 3h quinazolinone and 2aminoquinazoline derivatives catalyzed synthesis of quinazolinone and quinazoline derivativexuhu huang,s a,b haijun yang,a hua fu,a renzhong qiao,b yufen zhaoa a key laboratory of bioorganic phosphorus chemistry and chemical biology ministry of education, department of chemistry. Synthesis, tautomeric structure and antimicrobial activity of 3arylhydrazono 4 phenyl1,2, 4 triazepino2,3aquinazoline.
Synthesis, spectroscopic characterization, and time. Review article chemical characteristics, synthetic methods. Characterization and physical data of synthesized compounds compound no solvent formula m. Reactions associated with tautomeric nature of the quinazolinones are often quite complex and generally unpredictable. Pdf implication of quinazoline43hones in medicinal chemistry. The carbonyl group can be converted to enol form due to transfer of one of the. It turned out that direct attachment of a benzene ring to a heterocycle. Quinazolinone have strong lactamlactam tautomeric interaction. These heterocyclic compounds bear a close structural resemblance to arborine, the chief alkaloid of the indian medicinal plant, glycomis arborea correa.
The different molecular structures have been optimized using the functional density theory dft 22 23 24. Gene or point mutations are stable changes in genes i. Examples, written so as to illustrate the general pattern given above, include. It is very important to note that the tautomers are not the resonance structures of same compound. Introduction, history, and recent developments enol k f kr keto 1. Pdf synthesis, tautomeric structure and antimicrobial. These metrics are regularly updated to reflect usage leading up to the last few days. Although each gene is a potential site for a mutation, yet some genes mutate more frequently than other genes. The one pot reaction of ii with the appropriate aromatic aldehydes and anhyd. Other names such as phenmiazine, benzyleneamidine, benzo,diazine,benzopyrimidine, and,diaza napthaline have. The data from antibacterial examinations indicated that the substituent on the phenyl ring exerted significant influence on the antibacterial.
Ir, uv, and nmr spectral analysis, it could be shown that the 43h. Quinazolinone is a heterocyclic chemical compound, a quinazoline with a keto group. The tautomerism of the title compounds was investigated by1h,cnmr and uv spectroscopy. Researcharticle synthesisofanactivatabletetrasubstitutednickel phthalocyanines 43h quinazolinoneconjugateandits antibacterialactivity asmam.
The reactions of compound 1 with phosphorus oxychloride, phosphorus pentasulfide, ethyl chloroformate, ethyl chloroacetate. The enolenol equilibrium is very fast figure 1 molecular schematic for the ketoenol equilibrium in 2, 4 pentanedione, commonly referred to as acetylacetone acac. Two crystalline components isolated from the defensive secretion of the glomerid millipede, glomeris marginata, are identified as 1 methyl 2 ethyl 4 3h quinazolinone and 1,2 dimethyl 4 3h quinazolinone. Though the number of cases and deaths associated with malaria are decreasing in recent years, it is the most deadly disease in the world. When we draw a ketone or aldehyde using the lewis structure convention, we show a double bond between the carbonyl carbon and the oxygen this is known as the keto form. This study aimed at investigating the in vivo antimalarial activities of some 2,3disubstituted 4 3h quinazolinone derivatives. Synthesis, tautomeric states and crystal structure of zethyl 2cyano23hquinazoline 4ylidene acetate and zethyl 2cyano22methyl3hquinazoline 4ylidene acetate.
Tautomers are in dynamic equilibrium with each other, resonating structures a re not in dynamic equilibrium. Implication of quinazoline43hones in medicinal chemistry. Tautomerism is an especially important equilibrium in 1,3dicarbonyl compounds. These compounds contain a benzene ring fused with a heterocyclic ring of 2pyridinone, 2pyrazinone, or 4 pyrimidinone. Tautomerism has no effect on bond length, while resonance affects the bond length singl e bond is shortened while the double bond becomes longer. Thus 4 hydroxyquinazoline, tautomeric with 4 keto 3, 4 dihydroquinazoline, is commonly named 4 3 quinazolone or simply 4 quinazolone. We will use aqueous acid or aqueous base to keep our mechanisms simple, but other. Pdf synthesis, tautomeric states and crystal structure. These are reactions that can occur in acid or in base. Synthesis of new 43hquinazolinone derivatives under. Some marketed available drugs contain quinazoline and quinazolinone moiety. Synthesis and biological activity of new schiff bases.
General description the ftir and ftraman spectra of 2mercapto 4 3h quinazolinone has been studied. In vivo antimalarial evaluation of some 2,3disubstituted. The structure 4 can exist in one of the possible tautomeric forms 4ad as. Tautomerism, the existence of two or more chemical compounds that are capable of facile interconversion, in many cases merely exchanging a hydrogen atom between two other atoms, to either of which it forms a covalent bond. Brief account of reactivity of 4 3h quinazolinones reactions associated with tautomeric nature of the quinazolinones are. Chain tautomerism of the novel 2ferrocenyl2, 4 dihydro1h3,1benzoxazine. Annular tautomerism is a type of prototropic tautomerism wherein a proton can occupy two or more positions of a heterocyclic system, for example, 1h and 3himidazole.
The aim of this study was to synthesize a series of nickeliiphthalocyanines nipcs bearing four 4 3h quinazolinone ring system units, qz 4 nipcs 4ad. Two specific further subcategories of tautomerizations. Pdf a simple strategy for the synthesis of the hitherto unreported 3arylazo4 phenyl1,2,4triazepino2,3hquinazoline2,71hdiones is described find. These systems exhibit lactamlactim tautomerism and undergo hydroxy group replacement reactions. Disperse dyes based on 2methyl3 3aminophthalimido 4.
These two molecules are of interest as analogues of the known p53 reactivator 2vinyl 43hquinazolinone. Alkylation of 2mercapto 4 3h quinazolinone has been reported application 2mercapto 4 3h quinazolinone was employed as a modifier for the carbon paste electrode, for voltammetric determination of mercury. Synthesis, anticonvulsant activity, and sar study of novel. The crude compounds were filtered, washed several times with hot water then recrystallized from ethanol. Synthesis of new 43hquinazolinone derivatives using 5. Some of the important types of gene mutations of dna chain are. The structure 4 can exist in one of the possible tautomeric forms 4ad as shown in figure 1. Ringchain tautomerism in 1,3oxazines the journal of. Reddys laboratories, bachupalli, hyderabad, india, 500 072 bdepartment of chemistry, college of engineering. Compound5 was compared with respect to its spectra with those of appropriate model compounds1,3, 4, and6. The direction 1 is the equilibrium frome keto to enol and direction 2 is enol to keto.