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.     

Carbon-13 nuclear magnetic resonance spectra of N-substituted 2-amino-4H-3,1-benzoxazin-4-ones and 3-substituted 2,4-(1H,3H)quinazolinediones

¹³C chemical shifts of nine N-substituted 2-amino-4H-3,1-benzoxazin-4-ones, the isomeric 3-substituted 2,4-(1H,3H)quinazolinediones, and the parent compounds of the two series are reported. Support is provided for the endocyclic position of the C=N bond in the former series of compounds.     

Synthesis and reactions of 2-[α-(3,4-disubstituted phenacyl)-p-substituted styryl]-4H-3,1-benzoxazin-4-ones

Science Department, Faculty of Teachers, P.O.Box 2313, Al Hasa, 31982, Saudi Arabia Faculty of Engineering, Ain Shames University, EgyptChemistry Department, Faculty of Science, Ain Shames University, Egypt     

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.     

Fluorine-containing heterocycles: XIX. Synthesis of fluorine-containing quinazolin-4-ones from 3,1-benzoxazin-4-ones

Reactions of fluorine-containing 3,1-benzoxazin-4-ones with ammonium acetate, hydrazine, and heteroaromatic amines gave new 3H-, 3-amino-, and 3-hetarylquinazolin-4-ones, respectively. Differences in the conditions of formation of benzoxazinones from anthranilic acids with different fluorination patterns and in the reactions of fluorinated 3,1-benzoxazinones with nitrogen-centered nucleophiles were revealed.     

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 of 3-(4-Oxo-4H-3,1-benzoxazin-2-yl)-1-benzenesulfonyl Chloride and Its Reactivity toward Amines

3-(4-Oxo-4H-3,1-benzoxazin-2-yl)-1-benzenesulfonyl chloride was synthesized, and reactivity of its functional groups was studied. Reactions of the title compound with equimolar amounts of aniline and piperidine gave the corresponding sulfonamides with retention of the benzoxazine moiety. The same reactions with excess amine resulted in opening of the oxazine ring and formation of o-(m-aminosulfonylbenzoylamino)benzamides.     

Intramolecular photoinduced proton transfer in 2-(2-aminophenyl)-4H-3,1-benzoxazin-4-ones with different electron-withdrawing N-substituents

Fluorescence spectra of N-substituted 2-(2-aminophenyl)-4H-3,1-benzoxazin-4-ones consist of two bands, the long-wavelength band with anomalous Stokes shift, which corresponds to the emission of the product of intramolecular photoinduced proton transfer, and the short-wavelength band belonging to the form in which proton transfer does not occur. It is assumed that there is equilibrium between two planar rotamers in the ground state: one with the N-H…N hydrogen bond in which the intramolecular photoinduced proton transfer occurs and the other with the N-H…O bond, which does not experience hydrogen transfer. According to ab initio quantum-chemical calculations, the potential energy of proton transfer in the first excited singlet state has a potential barrier of 2.1–26.8 kJ/mol depending on the electron-withdrawing ability of the substituent on the amino group.     

1H and 13C NMR spectral studies of some 4H-3,1-benzoxazin-4-ones and their 2-acylaminobenzoic acid precursors

The 1H and 13C NMR spectra of twelve 4H-3,1-benzoxazine-4-ones and of their acylaminobenzoic acid precursors are presented. Differentiation between these two series of compounds is best achieved through the characteristic J(CH) coupling interactions in the high frequency carbonyl region. Some 4H-pyrido[2,3-d][1,3]oxazin-4-ones have also been studied and some earlier literature assignments revised.     

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.     

Synthesis of 4H-1,3-benzoxazin-4-onium salts and 4-H-1,3-benzoxazin-4-ones

Salicylamide and its substituted derivatives react with aliphatic carboxylic acid anhydrides and perchloric acid to give 4H-1,3-benzoxazin-4-onium salts. These same compounds were obtained by acidic cyclization of O- and N-acylsalicylamides. The synthesized salts are converted to 2-substituted 4H-1,3-benzoxazin-4-ones by the action of triethylamine and are hydrolyzed by water to N-acylsalicylamides. The probable reaction scheme is examined.     

Synthesis of NSC-341,964: An unexpected study on the stability of 2-aryl-4H-3,1-benzoxazin-4-ones

Resynthesis of NSC 341,964, which had been assigned structure 1 (1-[[3-(7-chloro-4-oxo-4H-3,1-benzoxazin-2-yl)phenyl]methyl]pyridinium chloride) was approached via 7-chloro-2-(3-methylphenyl)-4H-3,1-benzoxazin-4-one ( 5 ) obtained from 3-methylbenzoyl chloride ( 2 ) and 2-amino-4-chlorobenzoic acid ( 3 ) followed by dehydration in acetic anhydride. Radical bromination provided 6 which with pyridine afforded the bromide analog 7 of 1 . Ion exchange, however, gave ring-opened benzoic acid 8 rather than 1 . The original sample of NSC 341,964 also proved to be ring-opened material. However, 7 upon standing exhibited slow hydrolysis to 8 so that the structure of the original NSC 341,964 remains uncertain. A more direct route to compound 8 is also described.     

The preparation of 2H-1,4-benzoxazin-3-(4H)-ones via palladium-catalyzed intramolecular C-O bond formation

Pd/PtBu(3)-catalyzed intramolecular C-O bond formation has been used to access aryl- and alkyl-substituted benzoxazinones.     

A Simple Indirect Route for the Synthesis of N-Alkyl-4-imino-1,4-dihydro-2H-3,1-benzoxazin-2-ones

Summary. Novel N-alkyl-4-imino-1,4-dihydro-2H-3,1-benzoxazin-2-ones were synthesized in a single step by Baeyer–Villiger oxidation of N-alkyl-3-imino-2-indolinone derivatives in high yields. The structures of the products were determined by spectral data and by X-ray diffraction. Besides their novel structures, these compounds may have important biological activities and industrial applications.     

Synthesis of polyamides by ring-opening polyaddition of bis-3,1-benzoxazin-4-ones with aliphatic diamines

Open-chain polyamides with inherent viscosities of 0.1–0.6 were prepared in nearly quantitative yields by the ring-opening polyaddition of combinations of six bis-3,1-benzoxazin-4-one monomers and two aliphatic diamines in polar aprotic solvents at 80°C or below. The polymerization carried out in dimethyl sulfoxide at 80°C was best for preparing high-molecular-weight polymers. These polyamides were generally soluble in polar aprotic solvents, m-cresol, and pyridine.     

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.