Synthesis of 2H-3,1-pyrazolo[3,4-e]oxazines via a new conversion of Friedlander reaction

2H-3,1-Pyrazolo[3,4-e]oxazines (5a-c) and tacrine analogies (6a-c) were designed and prepared using 5-amino-4-cyanopyr-azole (7) and cycloketones (2a-c) as reactants. The study demonstrated that the new conversion existed in the Friedlander reaction of o-aminocyanopyrazole with cycloketones.     

Synthesis of 4-Halo-3-isopropoxyfuro[3,4-с]-pyridin-1(3H)-ones

Russian Journal of Organic Chemistry - The reaction of 4-halo-3-hydroxyfuro[3,4-c]pyridin-1(3H)-ones with propan-2-ol leads to the formation of 4-halo-3-isopropoxyfuro[3,4-c]pyridin-1(3H)-ones. The...     

Synthesis of novel 6-methyl-4-sulfanylfuro[3,4-с]pyridin-3(1H)-ones

Chemistry of Heterocyclic Compounds - Alkylation of 6-methyl-4-thioxo-4,5-dihydrofuro[3,4-c]pyridin-3(1H)-one in an alkaline medium proceeds regioselectively at the sulfur atom to form sulfanyl...     

Synthesis and reactions of 9-hydroxy-(α-alkoxycarbonylalkyl)-4-azafluorenes

The Reformatsky reaction with 4-azafluorenone has given 9-hydroxy-9-(-alkoxycarbonylalkyl)-4-azafluorenes. The course of this reaction with respect to the -haloester used, and the conversion of these hydroxyesters into hydroxy- and ,-unsaturated acids have been examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 81–85, January, 1991.     

Synthesis and Bioactivity of Some New 2-(Alkoxy carbonyl alkyl)-6-bromo-3,4-dihydro-3-(α-methyl benzyl)-2-oxo- benzo[e] [2H-1,3,2-oxazaphosphinine] Derivatives

Synthesis of some new 2-(alkoxy carbonyl alkyl)-6-bromo-3,4-dihydro-3-(α-methyl benzyl)-2-oxo-3-benzo- [e][2H-1,3,2-oxazaphosphinine] derivatives was accomplished through a two step process, which involves the condensation of 2-[(α-methylbenzyl amino)methyl]-4-bromophenol (1) with phosphorus oxychloride in equimolar quantities in the presence of triethylamine in dry toluene in 50—55 ℃ producing the corresponding intermediate (2), and subsequent reaction with the amino acid alkyl ester in dry tetrahydrofuran in the presence of triethylamine at different temperatures. They exhibited significant antibacterial and fungal activity.     

Synthesis of spiro[furan-3,3′-indolin]-2′-ones by PET-catalyzed [3+2] reactions of spiro[indoline-3,2′-oxiran]-2-ones with electron-rich olefins

An efficient procedure for the synthesis of spiro[furan-3,3′-indolin]-2-ones and dispiro[cycloalkane-1,2′-furan-3′,3″-indolin]-2″-ones has been achieved in high yields and stereoselectivity by photoinduced electron transfer-catalyzed [3+2] reactions of substituted spiro[indoline-3,2′-oxiran]-2-ones with olefins. The reactions proceed by ring opening of spiro[indoline-3,2′-oxiran]-2-ones via C_β–O bond cleavage and subsequent cycloaddition with olefins by using 2,4,6-triphenylpyrylium tetarfluoroborate (TPT) as a sensitizer.     

Polyanthranilides. III. Synthesis and Characterization of Polyamides from 6,6′-Bis[3,1-benzoxazin-2,4-dione]

Ring-scission polymerization of 6,6′-bis[3, 1-benzoxazin-2,4-dione] was studied in presence of such catalysts as aqueous HC1, benzidine-3,3′-dicarboxamide, N-methyl aniline, o-chloroaniline, benzidine-3,3′-dicarboxylic acid, and acid amides under various experimental conditions. It was found that 6,6′-bis[3,1-benzoxazin-2,4-dione] undergoes ring-scission polymerization, affording polyanthranilides in the presence of the first five catalysts under appropriate experimental conditions. The samples are insoluble in all organic solvents including formic acid. They are soluble in sulfuric acid with degradation. They are characterized by IR spectral and thermogravimetric analysis.     

Novel One-Pot Multicomponent Synthesis of Substituted 2,3-Dihydro-2-(6-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)phthalazine-1,4-diones and Substituted 3-[3-(N′-Benzylidene-hydrazino)-7H-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazin-6-yl]-4-hydroxy-6-methyl-pyran-2-ones

A one-pot procedure has been developed for the synthesis of substituted 2,3-dihydro-2-(6-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-7H-[1,2,4]triazolo[3,4-b] [1,3,4]thiadiazin-3-yl)phthalazine-1,4-diones by reaction of 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and phthalic anhydrides in acetic acid medium. Similarly, a one-pot, three-component synthetic procedure has been developed for substituted 3-[3-(N¹-benzylidene-hydrazino)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-6-yl]-4-hydroxy-6-methyl-pyran-2-ones from 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and various aromatic aldehydes in absolute ethanol and a few drops of glacial acetic acid.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Synthesis and Crystal Structure of Bis[2-[2-(diethylamino)ethyliminomethyl]-4-nitrophenolato]dimethanolcobalt(II) Dinitrate

1 INTRODUCTION The significance of cobalt coordination com- pounds in biological systems is recognized[1～3]. In many instances the cobalt coordination compounds of Schiff bases have been suggested as models to describe energy transfer in naturally occurring systems. In such cases the coordination sphere about the metal ion is believed to play an important role in determining the nature of the model system[4, 5]. In order to investigate the structures of such complexes, we report herein t…     

Synthesis and Crystal Structure of 2-Amino- 5,6-dihydro-4-（3,4-dimethoxyphenyl）-4H- benzo[h]chromene-3-carbonitrile

1 INTRODUCTION 2-Aminochromene is an important class of com- pounds found as the main compounds of many natu- rally occurring products employed as cosmetics and pigments and utilized as potential biodegradeable agro- chemicals[1～3]. In recent years, montmorillonite in natural and ex- changed forms has received considerable attention in different organic syntheses because of its environ- mental compatibility, low cost, high selectivity, reusa- bility and operational simplicity[4], such as …     

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.     

Synthesis of Derivatives of 4-Hydroxy-2-methyl-3-[2-(5-mercapto-1H-1,2,4-triazol-3-yl)ethyl]quinoline and 2-[2-(4-Hydroxy-2-methyl-3-quinolyl)ethyl]-4H-3,1-benzoxazin-4-one

From 4-hydroxy-2-methylquinoline-3-propionyl chlorides hydrochlorides the corresponding thiosemicarbazides were synthesized. The cyclization of the latter both in alkaline and acidic media furnished 4-hydroxy-2-methyl-3-[2-(5-mercapto-1H-1,2,4-triazol-3-yl)ethyl]quinolines. The reaction of the above propionyl chlorides with anthranilic acid afforded the corresponding 2-[2-(4-hydroxy-2-methyl-3-quinolyl)ethyl]-4H-3,1-benzoxazin-4-ones.     

Synthesis of the methanesulfonates of α-(4-chlorophenyl)-α-[1-(2-chlorophenyl)emenyl]-1H-1,2,4-triazole-1-ethanol and α-[1-(2-chlorophenyl)ethenyl]-α-(2,4-difluorophenyl)-1H-1,2,4-triazole-1-ethanol,alpha styryl carbinol antifungal agents

The methanesulfonates of (α-(4-chlorophenyl)-α-[1-(2-chlorophenyl)ethenyl]-1H-1,2,4-triazole-1-ethanol and α-[1-(2-chlorophenyl)ethenyl]-α-(2,4-difluorophenyl)-1H-1,2,4-triazole-1-ethanol ( 1a, b ) are orally effective α-styryl carbinol derivatives developed for the treatment and prevention of systemic fungal infections. Practical new processes amenable for the large-scale production of these compounds are described. Of note is the selection of dichlorostyrene as a convenient precursor of the styryl portion, modification of a sensitive Grignard addition into a realistic preparative reaction and the use of 1,2,4-triazole simultaneously as a base transfer agent and nucleophile.     

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.     

Synthesis of 1H-[1]benzothiopyrano[3,4-d]imidazol-4-ones

By the condensation of 3,4-diaminothiocoumarins containing primary or secondary amino groups in position 4, with formic and acetic acids (or acetic anhydrides), a number of 1H-[1]benzothiopyrano[3,4-d]imidazol-4-ones and their 2-methyl derivatives have been synthesized; the latter have also been obtained from the corresponding 3-monoacetylamino-4-aminothiocoumarins. By the acetylation of 3-4-diaminothiocoumarins with tertiary amino groups in positions 4 their 3-diacetyl derivative has been obtained, and these, under the action of bases, have been converted into 3-N-acetyl derivatives. The structures of the compounds synthesized have been confirmed by IR, PMR, and mass spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 479–483, April, 1980.     

4-Substituted-3,4-dihydro-3-methyl-2H-1,3-benzoxazin-2-ones. III (2,3). Solvolytic-reductive transformation of 4-(2-keto)-benzoxazin-2-ones into oxazin-2-ones

A series of 4-(2-keto-substituted)-3,4-dihydro-3-methyl-2H-1,3-benzoxazin-2-ones 1 (Table I) was synthesized by condensation of 3-alkyl-3,4-dihydro-4-hydroxy-2H-1,3-benzoxazin-2-ones 4 with ketones 5 having active alpha hydrogens. In the presence of alcoholic potassium borohydride, compounds 1 underwent reductive transacylation to give 1,3-oxazin-2-one derivatives 3 (Table III, a,b,c). When the other side of the ketone possessed substituents other than hydrogen, there were always also normal reduction products, i.e., secondary alcohols 2 (Table II) in addition to 3.     

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.     

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.     

Heteroannulated Quinazoline and Quinazolinone Derivatives from (Z)-2-[1-Benzamido-2-(3,4,5-trimethoxyphenyl)]vinyl-3,1-benzoxazin-4(3H)-one

The title compound 1 was prepared and allowed to react with a series of nitrogen nucleophiles to afford the quinazoline and quinazolinone derivatives 2–12 and tetrazole derivative 13. The IR, ¹H NMR, ¹³C NMR, and mass spectra of all the synthesized compounds were discussed.