2-Aryl-4H-3,1-benzoxazin-4-ones nitration

2-(3-Nitrophenyl)-4H-3,1-benzoxazin-4-one is formed in the nitration of 2-phenyl-4H-3,1-benzoxazin-4-one, while 2-(2-tosylamino-5-nitrophenyl)-4H-3,1-benzoxazin-4-one is formed in the nitration of 2-(2-tosylaminophenyl)-4H-3,1-benzoxazin-4-one.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 908–909, July, 1974.     

4H-3,1-Benzoxazin-4-ones methoxy-substituted 2-(2-arenesulfonylaminophenyl)-4H-3,1-benzoxazin-4-ones

Methoxy-substituted 2-(2-tosylaminophenyl)-4H-3,1-benzoxazin-4-one and 2-phenyl-4H-3,1-benzoxazin-4-one were synthesized. Their UV, IR, and luminescence spectra were studied. The position of the methoxy group affects the strength of the intramolecular hydrogen bond (IHB). The luminescence properties of methoxy-substituted 2-(2-tosylaminophenyl)-4H-3,1-benzoxazin-4-ones are associated with the strength of the IHB. The luminescence maximum is shifted to the short-wave region with strengthening of the IHB, and the luminescence intensity increase simultaneously.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1028–1032, August, 1971.The authors thank Yu. S. Ryabokobylko and A. O. Zisman for measuring the absorption spectra in the IR and UV regions.     

Nitro-substituted 2-phenyl- and 2-(2-tosylaminophenyl)-4H-3,1-benzoxazin-4-one

Nitro-substituted 2-phenyl- and 2-(2-tosylaminophenyl)-4H-3,1-benzoxazin-4-ones were synthesized. The UV, IR, and luminescence spectra were studied. The position of the nitro group affects the strength of the intramolecular hydrogen bond (IHB). The luminescence properties of nitro-substituted 2-(2-tosylaminophenyl)-4H-3,1-benzoxazin-4-ones are associated with the strength of the IHB. The luminescence maximum is shifted to the short-wave region as the IHB becomes stronger.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 616–621, May, 1972.     

Conformational effects in excited-state intramolecular proton transfer in <Emphasis Type="Italic">N</Emphasis>-substituted 2-(2-aminophenyl)-4H-3,1-benzoxazin-4-ones

The conformational effects in the ground and excited states were studied for N-substituted 2-(2-aminophenyl)-4H-3,1-benzoxazin-4-ones. The structural relaxation of the excited ESIPT product was revealed, which results in the formation of a nonplanar conformer undergoing efficient nonradiative deactivation. The aggregation of fluorophore molecules was observed in saturated hydrocarbons at low temperatures for N-substituted 2-(2-aminophenyl)-4H-3,1-benzoxazin-4-ones with the amido carbonyl group. Excited-state intramolecular proton transfer was not observed in this associate, and the fluorophore molecules were shown to occur in the nonplanar conformation, in which there is no intramolecular hydrogen bonding.     

Facile synthesis and herbicidal evaluation of 4H-3,1-benzoxazin-4-ones and 3H-quinazolin-4-ones with 2-phenoxymethyl substituents

Series of 4H-3,1-benzoxazin-4-ones and 3H-quinazolin-4-ones with phenoxy-methyl substituents were rationally designed and easily synthesized via one-pot N-acylation/ring closure reactions of anthranilic acids with 2-phenoxyacetyl chlorides to yield the 4H-3,1-benzoxazin-4-ones, and subsequently substituted with amino derivatives to obtain the 3H-quinazolin-4-ones. The herbicidal evaluation was performed on the model plants barnyard grass (a monocotyledon) and rape (a dicotyledon), and most of the title compounds displayed high levels of phytotoxicity. The active substructure and inhibitory phenotype analysis indicated that these compounds could be attributed to the class of plant hormone inhibitors. A docking study of several representative compounds with the hormone receptor TIR1 revealed an appreciable conformational match in the active site, implicating these compounds are potential lead hits targeting this receptor.     

Synthesis and transformation of amides of 4H-3,1-benzoxazin-4-one-2-carboxylic acid

A method for the preparation of amides of 4H-3,1-benzoxazin-4-one-2-carboxylic acid was developed, and N-R-amides of 3-R-4(3H)-quinazolone-2-carboxylic acid were synthesized from them.     

2-Benzoylamino-6,7-dimethoxy-4H-3,1-benzoxazin-4-one: Synthesis and investigation of serine protease inactivation

Summary 2-Benzoylamino-6,7-dimethoxy-4H-3,1-benzoxazin-4-one was prepared by thermal treatment of 2-(3-benzoylthioureido)-4,5-dimethoxybenzoic acid and by benzoylation of 2-amino-6,7-dimethoxy-4H-3,1-benzoxazin-4-one. The inactivation of chymotrypsin and human leukozyte elastase by the title compound and 2-benzoylamino-4H-3,1-benzoxazin-4-one is reported.

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2-Benzoylamino-6,7-dimethoxy-4H-3,1-benzoxazin-4-on: Synthese und Untersuchung der Inaktivierung von Serin-Proteasen

Zusammenfassung 2-Benzoylamino-6,7-dimethoxy-4H-3,1-benzoxazin-4-on wurde durch thermische Behandlung von 2-(3-Benzoylthioureido)-4,5-dimethoxybenzoesäure und durch Benzoylierung von 2-Amino-6,7-dimethoxy-4H-3,1-benzoxazin-4-on hergestellt. Über die Inaktivierung von Chymotrypsin und humaner Leukozyten-Elastase durch die Titelverbindung und 2-Benzoylamino-4H-3,1-benzoxazin-4-on wird berichtet.

     

Synthesis of some quinazolines derived from 6,8-dibromo2-(2-carboxyphenyl)-4h-3,1-benzoxazin-4-one as antimicrobial agents

The reactivity of 6,8-dibromo-2-(2-carboxyphenyl)-4H-3,1-benzoxazin-4-one towards the action of electrophilic and nucleophilic reagents led to the direct formation of heterobicyclic nitrogen compounds. The antimicrobial activity of some synthesized compounds was investigated.     

Reaction of anthranilic acid and methoxy- and nitro-substituted anthranilic acid with p-toluenesulfonyl chloride in pyridine

The reaction of anthranilic acid and methoxy- and nitro-substituted anthranilic acid with p-toluenesulfonyl chloride in pyridine was investigated. Anthranilic acid and its methoxy-substituted derivatives react to give the corresponding 2-(2-tosylaminophenyl)-4H-3,1-benzoxazin-4-ones and N,N'-ditosyldianthranilides. At 20°C, 4-nitroanthranilic acid gives primarily 2-(2-amino-4-nitrophenyl)-7-nitro-4H-3,1-benzoxazin-4-one, while its tosyl derivative is obtained at 114°. The products of the reaction of 5-nitroanthranilic acid with p-toluenesulfonyl chloride are 2-nitro-11H-pyrido[2,1-b]quinazolin-11-one and 2-(2-amino-5-nitrophenyl)-6-nitro-4H-3, 1-benzoxazin-4-one. The yield of benzoxazinone generally increases as the temperature is raised.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1341–1344, October, 1972     

2-Aryl-4H-3,1-benzoxazin-4-ones. Reduction

The reduction of 2-(2-tosylaminophenyl-4H-3,1-benzoxazin-4-one with zinc dust in acetic acid gives N-(o-tosylaminobenzyl)anthranilic acid, the structure of which was proved by mass spectrometry and the ¹³C NMR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1619–1621, December, 1977.     

2-Carbethoxymethyl-4H-3,1-benzoxazin-4-one. 4. Reaction with anilines

In a solution of DMF, 2-carbethoxymethyl-4H-3,1-benzoxazin-4-one reacts with primarily aromatic amines basically with the formation of the corresponding 2-carbethoxymetlzyl-3-arylquinazolin-4(3H)-ones. Possible mechanisms of these chemical transformations are reported and discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 225–228, February, 1994. Original article submitted June 28, 1993.     

2-Carbethoxymethyl-4H-3,1-benzoxazin-4-one. 3. Condensation of o-phenylenediamive

3-(2-Benzimidazolyl)-4-hydroxy-2-quinolone was unexpectedly obtained as the principal reaction product on fusion of 2-carbethoxymethyl-4H-3,1-benzoxazin-4-one with o-phenylenediamine. A possible mechanism of its formation is presented.For Communication 2 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 239–241, February, 1992.     

2-Carbethoxy-4H-3,1-benzoxazin-4-one. 2. Hydrazinolysis

3-Amino-2-carboxymethylquinazolin-4(3H)-one was obtained by hydrazinolysis of 2-carbethoxymethyl-4H-3,1-benzoxazin-4-one. Its transformations into 2-hydroxypyrazolo[5,1-b]quinazolin-9(1H)-oneand3-amino-2-hydrazido-(orbenzylamido)carbonylmethylquinazoline-4(3H)-ones were studied.For Communication 1, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1128–1130, August, 1991.     

4H-3,1-benzoxazin-4-ones thermal cyclodehydration of N-benzoylanthranilic acid

Water is split out to form 2-phenyl-4H-3,1-benzoxazin-4-one when N-benzoylanthranilic acid is heated. A mass spectrometric study of O¹⁸-labeled N-benzoylanthranilic acid and the product of its thermal cyclodehydration showed that the oxygen atoms of the carboxyl and benzoyl groups participate equally probably in splitting out of water.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 614–615, May, 1977.     

Synthesis of benzoxazinone derivatives: a new route to 2 (N phthaloylmethyl)-4H-3,1-benzoxazin-4-one

A new method has been designed to prepare the known benzoxazinone derivative 2-(N-phthaloylmethyl)-4H-3,1-benzoxazin-4-one (4). The acyl chloride derivative N-phthaloylglycine reacts with anthranilic acid in chloroform, in the presence of triethylamine, to give an intermediate that is then reacted with cyanuric chloride, used as a cyclization agent, to produce the benzoxazinone derivative.     

4-Hydroxy-2-quinolones. 112. Reaction of 2-ethoxycarbonylmethyl-4H-3,1-benzoxazin-4-one with active methylene compounds

The reaction of 2-ethoxycarbonylmethyl-4H-3,1-benzoxazin-4-one with malononitrile in dry pyridine leads to 1-hydroxy-3,6-dioxo-4,6-dihydro-3H-pyrimido[1,2-a]quinoline-5-carbonitrile. Acetoacetic and cyanoacetic esters under analogous conditions form anilides of 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acid while diethyl malonate gives N,N′-di-2-carboxyanilides of malonic acid. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 75–79, January, 2007.     

Isolation and structure elucidation of genuine oat phytoalexin,avenalumin I

The major phytoalexin from oat leaves has been identified as 2-[2-(4-hydroxyphenyDethenyl] -6-hydroxy-4H-3,1-benzoxazin-4-one ($\text{A}$).     

2-Carbethoxy-4H-3,1-benzoxazin-4-one. 1. Synthesis and reaction mechanism of formation

The possibility was examined of using various condensing agents in the intramolecular cyclization reaction of ethyl ester of 2-carbomalonanilic acid into 2-carboethoxymethyl-4H-3,1-benzoxazin-4-one. It was found that the optimal reagent is dicyclohexylcarbodiimide. By using NMR spectroscopy and deutero-exchange it was shown that the cyclization proceeds with the participation of the hydroxyl group of the carboxyl and a proton of the amide function.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1123–1127, August, 1991.     

Synthesis of 5-fluoro-2-methyl-3-(2-trifluoromethyl-1,3,4-thiadiazol-5-yl)-4(3H)-quinazolinone and related compounds with potential antiviral and anticancer activity

The synthesis of ten new substituted 1,3,4-thiadiazolyl-4(3H)-quinazolinones 8–11, 13, 17 , and 20–23 is reported. Compounds 8–11 were prepared by condensation of 5-fluoro-2-methyl-3,1-benzoxazin-4-one (3) and 5-substituted 2-amino-1,3,4-thiadiazoles 4–7. Compound 13 was obtained by condensation of 5-fluoro-2-methyl-3,1-benzoxazin-4-one (3) with DL-α-amino-?-caprolactam (12) . Compound 17 was synthesized by condensation of 6-bromo-2-methyl-3,1-benzoxazin-4-one (16) and 2-amino-5-t-butyl-1,3,4-thiadiazole (5) . Compounds 20–23 were obtained by condensation of 5-chloro-6,8-dibromo-2-methyl-3,1-benzoxazin-4-one (19) and 5-substituted 2-amino-1,3,4-thiadiazoles 4–7, respectively. The substituted 3,1-benzoxazin-4-ones 3, 16, and 19 were obtained in good yield by refluxing the appropriate anthranilic acid, 1,15 , and 18 with acetic anhydride (2) .     

Direct oxidative cascade cyclisation of 2-aminobenzoic acid and arylaldehydes to aryl 4H-3,1-benzoxazin-4-ones with oxone

This paper presents a methodology of oxidative cascade cyclisation of 2-aminobenzoic acids and arylaldehyde using I₂ as a catalyst and an environmentally benign oxidant oxone. This method displays facile access to a diverse range of substituted aryl 4H-3,1-benzoxazin-4-ones. This synthetic methodology has many advantages such as: (1) easy availability of starting material, (2) transition metal-free condition (3) use of an environmentally benign oxidant.