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 photophysical properties of 2-styrylquinazolin-4-ones

trans-2-Styryl-substituted 3H-, 3-phenyl-, and 3-naphthylquinazolin-4-ones and their 6,7-difluoro derivatives were synthesized by condensation of appropriate 2-methylquinazolin-4-ones with aromatic aldehydes or by the transformation of the heterocycle of 2-methyl-3,1-benzoxazin-4-one under the action of benzylidenephenylamines.     

Liquid-crystal 4H-3,1-benzoxazln-4-ones

2,6-Disubstituted 4H-3,1-benzoxazin-4-ones that have mesogenic properties were synthesized by the reaction of 5-substituted anthranilic acid with aroyl chlorides in pyridine. The introduction of a 4H-3,1-benzoxazin-4-one fragment increases the absolute value of the anisotropy of the dielectric permeability. The temperatures and heats of the phase transitions are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1335–1337, October, 1981.     

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.     

Novel heterocycles derived from substituted aroylthioureas: Synthesis of 3, l-benzothiazin-4-ones,thieno[3,2-d][1,3]thiazin-4-ones and 1,2,4-thiadiazolo[2,3-a][3,1]benzothiazin-5-ones

A series of heterocyclic aroylthioureas has been prepared and investigated as starting materials for ring closure reactions. The formation of several new 3,1-benzothiazin-4-ones and thieno[3,2-d][1,3]thiazin-4-ones (via cyclocondensation reactions) is reported. Oxidative cyclizations were carried out to produce methyl benzothiazole-4-carboxylates (via formation of an S-C bond) as well as 1,2,4-thiadiazolo-[2,3-a][3,1]benzothiazin-5-ones (via formation of an S? N bond).     

The chemistry of 4H-3,1-benzoxazin-4-ones

The present review covers the synthesis and reactions of 4H-3,1-Benzoxazin-4-ones. Only those with carbon substituents at the 2-position are included. Literature corverage includes publications primarily from the mid 1960's to May 1998.     

One-Pot Synthesis of 2,3-Dihydro-2,3-disubstituted Benzo[g]-quinazolin-4(1H)-ones

Condensation of 2H-naphth[2,3-d][3,1] oxazin-2,4 (IH)-dione (1) with schiff bases (2) in acetic acid resulted in the formation of 2,3-dihydro-2,3-diarylbenzo[g]quinazolin-4(IH)-ones (3). Reaction of 1 with ketoanils generated in situ results in 2,3-dihydro-2,2-substituted-3-phenylbenzo[g]quinazolin-4 (IH)-ones (6) and the spiroalkanes (5). Dehydrogenation of 3 gave 2,3-diaryl benzo[g]quinazolin-4(3H)-ones (7).     

An efficient approach for the synthesis of N-Phenylcarboxamido-2-aryl-1,2-dihydro-(4H)-3,1-benzoxazine-4-ones

An efficient synthesis of N-phenylcarboxamodo-2-aryl-1,2-dihydro-(4H)-3,1-benzoxazin-4-ones is described by cyclization reaction of some 2-(benzylidene-amino)-benzoic acids with phenyl isocyanate under reflux conditions in CHCl₃. Higher yields of the products were produced in high purity with simple work-up.     

2-Aryl-substituted 4H-3,1-benzoxazin-4-ones as novel active substances for the cardiovascular system

4H-3,1-Benzoxazin-4-ones of the structural types 3 and 4 are accessible by cyclization reactions. The introduction of the phosphonate group was achieved by way of Wohl-Ziegler bromination and subsequent Michaelis-Arbuzow reaction with a trialkyl phosphite. Pharmacological investigations on isolated left atria, ileum specimens, and Langendorff hearts as well as in vivo circulatory studies on anesthetized rats revealed that the phosphonates 4 exert calcium antagonistic effects. Whereas 2-(arylvinyl)benzoxazinones gave rise to pronounced negative inotropic effects, compound 3e exhibited relaxing effects on smooth musculature in particular and markedly increased the coronary flow through Langendorff hearts.     

13C NMR spectra of some N-substituted 1,2-dihydro-3,1-benzoxazin-4-ones

The natural abundance ¹³C NMR spectra of a series of hitherto unknown l-atyl-methyl-1,2-dihydro-3,1-benzoxazin-4-ones have been recorded. The assignments of the various resonances have been made from chemical shift arguments, by the analysis of the fine splittings caused by one-bond and long-range couplings and also by comparison with model compounds.     

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.     

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.     

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.     

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.     

Synthesis of 4H-3,1-benzoxazines, quinazolin-2-ones, and quinoline-4-ones by palladium-catalyzed oxidative carbonylation of 2-ethynylaniline derivatives

An effective and straightforward approach to the synthesis of 4H-3,1-benzoxazines 3 and 4, quinazolin-2-ones 5, and quinoline-4-one derivatives 6 and 7 is provided by palladium-catalyzed cyclization-alkoxycarbonylation of variously substituted 2-(trimethylsilanyl)ethynylaniline amide or urea derivatives 2. Reactions are carried out in 7:1 MeCN/MeOH at 65 or 75 degrees C in the presence of catalytic amounts of 10% Pd/C in conjunction with Bu(4)NI and KF and under 2.4 MPa of a 3:1 mixture of CO and air. Anti and syn 6-exo-dig cyclization modes account for the formation of the two stereoisomers. Isomerization of the vinylpalladium intermediate may occur as well. Formation of a double carbonylation product 7r and of a gem-dimethoxycarbonylation product 6s, whose structures have been determined by X-ray diffraction analysis, is justified through an unusual type of rearrangement.     

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.     

A simple and expedient method for the stepwise synthesis of 2-ethoxy-(4H)-3,1-benzoxazine-4-ones

A simple and practical route is described for the synthesis of 2-efhoxy-(4H)-3,1 -benzoxazine-4-ones using the coupling reaction of anthranilic acid derivatives with diethyl dicarbonate following with fast cyclization of the carbamate adduct with a dehydrocyclization agent such as cyanuric chloride and N,N′-dicyclohexylcarbodiimide in PEG at room temperature.High yields of the products obtained under mild reaction conditions with simple work-up of the reaction mixture.     

Recent development in the synthesis of pyrrolin-4-ones/pyrrolin-3-ones

Pyrrolin-4-ones/pyrrolin-3-ones and its derivatives are important heterocyclic systems which are observed in vast variety of natural products, pharmaceuticals, and biologically important compounds. Different researchers all across the world have developed different synthetic methodologies for the construction of functionalized pyrrolin-4-ones/pyrrolin-3-one scaffolds such as the transition-metal catalyzed/mediated cycloisomerizations of 1-aminoynones and dimerization of enaminones or α-diazo-β-oxoamides etc. The present review article summarizes various reports on the synthesis of various simple and functionalized pyrrolin-4-ones/pyrrolin-3-ones from 2000 onward.     

Synthesis of 5,6-dihydro-4H-thiopyran-4-ones

The anions of 1,4-diaryl-3-buten-2-ones 1 reacts with arylisothiocyanates, yielding intermediates 4 which can ring close to 5,6-dihydro-4H-thiopyran-4-ones 5 . Under similar reaction conditions ethyl 3-oxo-4-pentenoates 7 gives the 6-spiropyrans 9 . Methylation of 3 gives the S-methylated open form 6 .     

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.