11.Use of 0002www.iiste.org Call_for_Paper-Ethoxy(4H)-3,1-benzoxazin-4-one as a Precursor (original) (raw)
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2012
The interactions of 2-ethoxy(4H)-3,1-benzoxazin-4-one (1) with various nitrogen nucleophiles such as ammonium acetate, hydrazine hydrate, ethanolamine, p-phenylenediamine, o-phenylenediamine, o- tolidine, dapsone, 2-aminophenol, 4-aminophenol, 4-aminobenzoic acid and 2-aminonicotinic acid have been discussed. The reactions of 2-thoxy-(3H)-quinazolin-4-one with ethyl chloroformate, phosphorus pentasulfide, chloroacetyl chloride and phosphorus oxychloride have also been investigated. Similar reactions of 2-ethoxy-4-chloroquinazoline with hydrazine hydrate and thiosemicarbazide have been introduced. Aminolysis of the 2-ethoxy group in some of the thiadiazoloquinazolinone derivatives has been attempted. The interactions of these aminolized derivatives and the 3-aminoquinazolinone with chloroacetyl chloride have been studied. All of the synthesized derivatives have been used in a wide range as starting materials for the synthesis of novel quinazoline and/or quinazolinones which have biological activity. The structures of all these products, obtained by heterocyclic ring opening and ring closure, were inferred by the IR, MS, 1H NMR spectral as well as elemental analyses.
2011
The behavior of 2-ethoxy-(4H)-3,1-benzoxazin-4-one (1) towards nitrogen nucleo- philes, e.g. ethanolamine, aromatic amines (namely: p -toluidine, p -anisidine, p -hydroxyaniline, o-hydroxyaniline, o-bromoaniline, o-phenylenediamine, p -phenylene- diamine, o-tolidinediamine) p-aminobenzoic acid, glucosamine hydrochloride, 2-amino- nicotinic acid, 1-naphthalenesulfonic acid hydrazide, n-decanoic acid hydrazide, benzoic acid hydrazide, semicarbazide, aminoacids (e.g. D,L-alanine, L-asparagine, L-arginine) and derivatives of 2-aminothiodiazole has been investigated. The behavior of the benzoxazinone towards a selected sulfur nucleophile, L-cysteine, has also been discussed. Formation of an amidine salt as a reaction intermediate has been assumed. The effect of solvent in some reactions has been elucidated. The structures of all the novel quinazoline and quinazolinone derivatives, obtained by heterocyclic ring opening and ring closure were inferred by the IR, MS as well as 1H-NMR spectral analysis. Moreover, the antimicrobial potential of some of the new synthesized derivatives has been evaluated
JOURNAL OF EDUCATION AND SCIENCE, 2021
In this research new compounds containing quinazolin-4(3H)-one nucleus linked to heterocyclic moieties were synthesized using ethyl (4'-oxoquinazolin-3'-yl) acetate (2) as a synthon. This compound was synthesized via 4-quinazolinone's (1) reaction with ethyl chloroacetate in the existence of K2CO3 as a base and acetone as a solvent. The ethyl α-(4'-oxoquinazolin-3'-yl) acetate (2) was converted to the corresponding hydrazide through its reaction with hydrazine hydrate (85 %). Compound (3) was reacted with two of acyl chlorides to synthesize the diacyl hydrazine compounds (4,5). The compound (5) was cyclized to the corresponding 1,3,4-oxadiazole (6) in presence of phosphorous oxychloride. The formyl derivative (7) of the hydrazide (3) was synthesized via its reaction with formic acid and consequently cyclized by phosphorous oxychloride to the corresponding 1,3,4-oxadiazole (8). The hydrazide (3) was also converted to the thiosemicarbazide derivative (9) by its reaction with ammonium thiocyanate under acidic conditions. Whereas other substituted thiosemicarbazide derivatives (10-12) were synthesized by the reaction of hydrazide (3) with organic isothiocyanate compounds. The resultant compounds (11, 12) were cyclized under basic conditions (4% sodium hydroxide solution) to give 1,3,4-triazole-2-thiole derivatives (13,14), whereas the cyclization of compounds (10-12) was performed under the acidic medium (conc. H2SO4) to give 2substituted amino-1,3,4-thiadiazoles (15-17). On the other side, the hydrazide's (3) reaction with isocyanate compounds affords the semicarbazide compounds (18,19). These compounds were cyclized under the basic condition to afford 1,3,4-triazol-2-ol compounds (20,21). The structures of the synthesized compounds were corroborated depending on the physical and spectral data.
Monatshefte f�r Chemie Chemical Monthly, 1983
The fusion of 2-acetamidonicotinic acid with o-toluidine, p-bromoaniline or okchloroaniline afforded the corresponding 3-aryl-2 methyl-pyrido-[2,3 d]pyrimidin-4(3H)-ones (4), the 8-aza analogs of 3-aryl-2-methyl-4quinazolinones, alongside 2-aminonieotinic acid. 2-Methyl-3-(2-methylphenyl)pyrido[2,3-dJpyrimidin-4(3H)-one (4 a), the 8-aza analog of methaqualone, was converted to the 2-substituted styryl derivatives 6 by condensation with some aromatic aldehydes and to the trieyclie system, 10-aza-5,6-dihydro-3-hydroxy-5-(2-methylphenyl):2 substituteddH pyrido[1,2-a]quinazoline-l,6-diones (8) by reaction with monosubstituted bis-2,4,6-triehlorophenyl malonates.
2011
The behavior of 2-ethoxy-4-chloroquinazoline 2 towards various nitrogen nucleophiles, namely: thiosemicarbazide, sodium azide, glucosamine, ethanol, and hydrazine hydrate has been discussed. Also, the behavior of 4-(2-ethoxyquinazolin-4-yl)thiosemicarba- zide towards one-carbon, for example, ethyl chloroformate, and two-carbon donors, for example, ethyl chloroacetate and diethyl oxalate has been investigated. On the other hand, new 5-ethoxy-2-substituted[1,2,4]-triazolo-[1,5-c]quinazoline derivatives have been obtained by ring closure accompanied with Dimroth rearrangement through the interaction of compound 2 with hydrazides of acetic, benzoic, crotonic, cinnamic, 2-furoic, and phthalimidoacetic acids. Structures of the novel products were confirmed by elemental, IR, MS, and 1H-NMR spectral analyses.
Collection of Czechoslovak Chemical Communications, 1992
Introducing of chlorine into biologically versatile heterocyclic rings might lead to the improveiiient of their phitrni;icologic;il ;tctivity. Therefore coinpounds II(i-IIr and IIIu-IIIf were preparcd with the a i m to cotiibitic t h e pcsticidiil qualities of hctcrocyclic nuclei. EXPERIMENTAL All melting points are uncorrected. The IR spectra were rccorded with Pyc Unicani SP 12oOCi spectrometer in KBr pellets. The 't1 NMR spectra were obtained in (CD3)2S0 using Varian A-60 MlIz spectrometer and tetramethylsilane as internal standard. The chemical shifts are reported i n 6, ppm. The mass spectra were determined with 7070 F spectrometer using direct inlet temperature 90 'C and energy of 70 eV. 5-Chloro and 3.5-dichloroanthranilic acids were prepared according to the method adopted by Endicott et at.'. Reaction of 2-Aryl-4-chloroc~uinazolincs lali with Anthranilic Acid Derivatives: Formation of Ila-I f r Equimolar amounts of 4-chloro-7-arylquinazolinr derivatives (lof f i and respective anthranilic acid derivative were refluxed in glacial acetic acid for 1 h. The reaction mixture was concentrated under vacuum, cooled, and poured into ice water. The crude product thus obtained was filtered off, washed twice with water and recrystallized from ethanol-acetone mixture (60 : 40). Basic physical, analytical and spectral data of products are reported in Tables I and 11. Reaction of 2-Aryl-4-cliloroquinazolines Inff with Sodium h i d e : Formation of flfa-I f f f An equimolar mixture of l-aryl-4-chloroquinazoline (la-fn and sodiuni azide was refluxed i n benzene for 5 h. The solvent was evaporated in vacuo. The oily residue was triturated scveral times with light petroleum. The obtained solid was washed with cold cthanol. collected, and recrystallized from ethanol. The products were identified as 5-aryltetrazolo[5,4-clquinazoline derivatives (Illal/fJ). Basic physical, analytical and spectral data are reported in Tables I and II.
2015
Pathogenic microbes have mutated and developed resistance to the latest range of antibiotics, which has kept synthetic chemist hunting for better and least toxic antimicrobial agents. Cyclocondensation of substituted anilines with 3-phenyl-2-propenoic acid yielded Phenyl-(substituted)-quinolin-2-one derivatives (1a–1t). In the next step phenylquinolin-2-one acetic acid derivatives (2a–2t) were prepared by the treatment of (1a–1t) with chloroacetic acid. Further (2a–2t) derivatives were reacted with thiocarbohydrazide to obtain a series of 4-amino-5-sulfanyl-4,5-dihydro-1,2,4-triazolo-4-pheny-(substituted)-quinolin-2-one derivatives (3a–3t). Then condensation of (3a–3t) with phenacyl bromide provided series of fused heterocyclic derivatives of 4-phenyl-1-({6-phenyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl}methyl)-(substituted)-1,2-dihydro quinolin-2-one (4a–4t). Structures of these newly synthesized derivatives were established by elemental analysis, FT-IR, 1H NMR and Mass spe...
Chemical and Process Engineering Research, 2011
The 2-{[5-(2-Amino-4-oxoquinazolin-3(4H)-yl)-1,3,4-thiadiazol-2-yl]methyl}-1H-isoindole-1,3(2H)-dione 1 was synthesized and allowed to react with each of p-methoxybenzaldehyde, p-methoxyacetophenone and chloroacetyl chloride to produce the Schiff bases 2 and 3 and 2-chloro-N-(3-{5-[(1,3-dioxo-1,3-dihydro-2Hisoindol-2-yl)methyl]-1,3,4-thiadiazol-2-yl}-4-oxo-3,4-dihydroquinazolin-2-yl)acetamide 6, respectively. The products 2 and 3 were reacted with phenyl isothiocyanate to afford 4 and 5. Derivative 6 was reacted with various nucleophiles, namely: thioglycolic acid, ethyl glycinate and 2-aminoethanol giving 7-9 respectively. In turn, the derivative 8 was reacted with α-bromoglucose tetraacetate affording product 8a whereas 9 was reacted with p-acetylaminobenzenesulfonyl chloride affording derivative 9a. Moreover, the reactions of the derivative 6 with potassium thiocyanate, potassium cyanate, malonitrile, ethyl cyanoacetate and ammonium acetate gave derivatives 10-15, respectively. All the synthesized derivatives were confirmed by the IR, mass, 1 H-NMR and elemental analysis.