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).     

Synthesis and Antimicrobial Evaluation of Some New 1,5-Benzothiazepine Derivatives and Their Ribofuranosides

( - )- cis -2(4-Methoxyphenyl)-3-hydroxy/methoxy-6,8-dichloro/6-chloro-2,3-dihydro-1,5-benzothiazepin-4[5H/5-chloroacetyl/5-(4'-methylpiperazino-1')acetyl]-ones have been synthesized by the condensation of 2-amino-3,5-dichloro/3-chloro benzenethiol with methyl-( - )- trans -3(4-methoxyphenyl)glycidate in xylene. Ribofuranosides viz ( - )- cis -2(4-methoxyphenyl)-3-methoxy-6,8-dichloro/6-chloro-2,3-dihydro-1,5-benzothiazepine-4-[5-(2',3',5'-tri- O -benzoyl- g -D-ribofuranosyl)-ones have been synthesized by the treatment of 3-methoxy derivatives of 1,5-benzothiazepines with sugar viz g -D-ribofuranose-1-acetate-2,3,5-tribenzoate in toluene at vacuo. Synthesized compounds have been characterized by elemental analysis, IR, 1 H NMR spectral studies and screened for their antimicrobial activity.     

Electron impact mass spectral fragmentation patterns of 2a,4-disubstituted 5-benzoyl-2-chloro-2a,3,4,5-tetrahydroazeto[1,2-a][1,5]benzodiazepin-1( 2H)-ones

The mass spectrometric behaviour of six 2a,4-disubstituted 5-benzoyl-2-chloro-2a,3,4,5-tetrahydroazeto[1,2-a][1,5]benzodia zepin-1(2H)-ones has been studied with the aid of mass-analysed ion kinetic energy spectrometry and accurate mass measurements under electron impact ionization. All compounds show a tendency to eliminate a chlorine atom, a chlorine atom plus benzaldehyde, benzoyl radical, chloroketene or chlorine atom plus CO and H2O molecules to yield, respectively, [M-Cl]+ ions, 2a,4-disubstituted 2a,3-dihydroazeto[1,2-a][1,5]benzodiazepin-1(2H)-one ions, [M-PhCO]+ ions, 2,4-disubstituted 1-benzoyl-2,3-dihydro-1H-1,5-benzodiazepine ions, or 1,2,4-trisubstituted 1H-1,7-benzodiazonine ions, which could also be formed from [M-Cl]+ ions by loss of CO and H2O molecules simultaneously. The [M-Cl]+ ions could further lose benzoyl radical to form [M-Cl-PhCO]+ ions, or lose benzoyl amide and undergo a rearrangement to form 4,6-disubstituted 1-benzoazocine-2(1H)-one ions. The [M-PhCO]+ ions could eliminate NH to produce 2a,4-disubstituted 2,2a,3,4-tetrahydroazeto[1,2,-a]quinolin-1-one ions, which could further eliminate chloroketene, CO and/or HCl to produce some important ions, respectively. 2,4-Disubstituted 1-benzoyl-2,3-dihydro-1H-1,5-benzodiazepine ions could lose benzoyl radical to yield 2,4-disubstituted 2,3-dihydro-1H-1,5-benzodiazepine ions, which could further yield other small fragment ions by loss of propene/styrene or small fragments.     

Reaction of 2,3-Dihydro-1,5-benzothiazepines and Phenylacetyl Chloride in the Presence of Triethylamine： A New Aspect on the Formation Mechanism of Dihydro-1,3-oxazin-4-one Derivatives

2a,4-Disubstituted 2,2a,3,4-tetrahydro-2-phenyl-1H-azeto[2,1-d][ 1,5]benzothiazepin-1-ones, as well as 2-substi-tuted 2,3-dihydro-3-phenylacetyl-2-styryl-benzothiazoles and 4a,6-disubstituted 3- .benzyl-4a,5-d/hydro-2-phenyl-1H,6H-[1,3]oxazino[2,3-d][1,5]benzothiazepin-1-ones, were obtained from the reaction of 2,4-disubstituted 2,3-dihydro-1,5-benzothiazepines with phenylacetyl chloride in the presence of triethylamine. The mechanism for the formation of 4a,5-dihydro-1H,6H-[1,3]oxazino[2,3-d][1,5]benzothiazepin-1-ones, 2,3-dihydro-1,3-oxazin-4-one derivatives, was suggested.     

Synthesis of new derivatives of 4-amino-2,4-dihydro-1,2,4-triazol-3-one as potential antibacterial agents

Thirty new 2-substituted-4-amino-5-alkyl or aryl-2,4-dihydro-1,2,4-triazol-3-ones and ten 2-substituted-5-alkyl or aryl-4-(5-nitro-2-furfurylidene)amino-2,4-dihydro-1,2,4-triazol-3-ones were synthesized and characterised by their sharp melting points, elemental analysis, ir and ¹H nmr spectra. These new derivatives of 5-nitro-2-furaldehyde were screened for their antibacterial activities. Most of the compounds showed good activity against one test organism, Staphylococcus aureus. For a few compounds, C.M.I. ranged from 4 to 8 μg/ml (higher results than nitrofurantoin).     

Reactions of 4-acyl-1-alkoxyaryl-5-aryl-3-hydroxy-2,5-dihydro-1H-pyrrol-2-ones with nucleophilic reagents

4-Acetyl-1-alkoxyaryl-5-aryl-3-hydroxy-2,5-dihydro-1H-pyrrol-2-ones reacted with amines to give 1-alkoxyaryl-5-aryl-4-(1-R-aminoethylidene)pyrrolidine-2,3-diones. Reactions of amines with 4-benzoyl-substituted analogs involve nucleophilic attack on the C³ atom in the heteroring to produce the corresponding 3-R-amino-1-alkoxyaryl-5-aryl-4-benzoyl-2,5-dihydro-1H-pyrrol-2-ones. Reactions of the title compounds with hydrazine hydrate, regardless on the substituent on C₄, afforded 4-aryl-3-methyl(phenyl)-5-[2(4)-methoxyphenyl]-4,6-dihydropyrrolo[3,4-c]pyrazol-6-ones.     

Condensed Isoquinolines. 10. Borohydride Reduction in the 5H-Isoquino[2,3-a]quinazolin-5-one Series

Borohydride reduction in a series of 7-benzyl- and newly synthesized 7-arylmethylene-7,12-dihydro-5H-isoquino[2,3-a]quinazolin-5-ones leads stereoselectively to erythro-7-benzyl-6,6a,7,12-tetrahydro-5H-isoquino[2,3-a]quinazolin-5-ones. 7,7-Disubstituted 7,12-dihydro-5H-isoquino[2,3-a]quinazolin-5-ones are inert to the action of sodium borohydride, but spiro[5H-isoquino[2,3-a]quinazolin-7(12H),2'-indane]-5-one is reduced under rigid conditions to 6,6a-dihydrospiro[5H-isoquino[2,3-a]quinazolin-7(12H),2'-indan]-5-one. 7-Acetyl- and 7-benzoyl-6,11-dihydro-5H-isoquino[2,3-a]quinazolin-5-ones are converted in an aqueous alcoholic solution of sodium borohydride to the previously described 6,6a,7,12-tetrahydro-5H-isoquino[2,3-a]quinazolin-5-one. The structure and special features of the conformational behavior of the reduction products obtained were demonstrated by ¹H NMR spectroscopy.!     

Interaction of 1-Benzyl-4-benzoyl-5-phenyl-2,3-dihydro-2,3-pyrroledione with Ketene Diethylacetal: Synthesis and Crystal and Molecular Structure of 1-Benzyl-4-benzoyl-3-hydroxy-5-phenyl-5-ethoxycarbonylmethyl-2,5-dihydro-2-pyrrolone

1-Benzyl-4-benzoyl-5-phenyl-2,3-dihydro-2,3-pyrroledione reacts with ketene diethylacetal, forming 1-benzyl-4-benzoyl-3-hydroxy-5-phenyl-5-ethoxycarbonylmethyl-2,5-dihydro-2-pyrrolone, whose crystal and molecular structure was studied by XRD.     

Chlorination of 4-methyl-8-methoxy-2,3-dihydro-1H,1,5-benzodiazepin-2-one

The results of the chlorination of 4-methyl-8-methoxy-2,3-dihydro-1H,1,5-benzodiazepin-2-ones are compared with the results of quantum-chemical calculations of 4-methyl-2,3-dihydro-1H-1,5-benzodiazepin-2-ones with various substituents in the benzene ring in the case of homolytic halogenation. The chlorination of 4-methyl-8-methoxy-2,3-dihydro-1H-1,5-benzodiazepin-2-one (I) with N-chlorosuccinimide leads to 3-chloro- and 3,3-dichloro-4-methyl-8-methoxy-2,3-dihydro-1H-1,5-benzodiazepin-2-ones, whereas chlorination with sulfuryl chloride leads to 4-chloromethyl and 3,3-dichloro-4-methyl derivatives. The IR, PMR, and mass spectra of the synthesized compounds are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1272–1274, September, 1981.     

Novel syntheses of 2,3-dihydro-1,5-benzothiazepin-4(5h)-ones and 2h-1,4-benzothiazin-3(4h)-ones

Nucleophilic additions of alpha-mercaptoalkanoate esters and beta-mercaptoalkanoate acids to benzoquinone diimines, followed by cyclization with trifluoroacetic acid or 1,3-dicyclohexylcarbodiimide (DCC), provide novel, high-yielding syntheses of 2H-1,4-benzothiazin-3(4H)-ones (3a-f) and 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones (5a-c), respectively.     

Oxazepines ano Thiazepines,XVII New Procedures for the Preparation of 2,3-Oihydro-1,5-Benzothiazepin-4(5H)-Ones Substituted in Position 2

Abstract

2,3-Dihydro-2-aryl-1,5-benzothiazepin-4(5)-ones and 2,3-disubstituted 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones have hitherto been synthesized by heating the mixture of 2-aminothiophenol and appropriately sub-stituted acrylic acids without solvent.^2–7 This is a very simple and convenient method, but because of the accompanying decompositions, the yield of the reaction is generally quite poor (20 ? 40%). For this reason, it seemed expedient to work out new procedures for the synthesis of these biologically important benzothiaze-pines. Preparation of 2,3-dihydro-2-phenyl-1,5-benzothia-zepin-4(5H)-one (20) was achieved by the ring enlargement of 1-thioflavanone⁸ but, because of the difficulties in the synthesis of the 1-thiochromanone deriva-tives in some cases, this procedure could hardly be generalized.     

Synthesis of functionalized 2,3-dihydrothieno[2,3-d]pyrimidin-4(1H)-ones and their recyclization to 2,3-dihydrothieno[3,4-d]pyrimidin-4(1H)-ones

By the reaction of 6-aryl(alkyl)amino-5-cyano-2,3-dihydro-1,3-thiazin-4(10)-ones with α-halogenoketones in the presence of triethylamine, 2,3-dihydrothieno[2,3-d]pyrimidin-4(1H)-ones have been synthesized and their acid-catalyzed recyclization to 2,3-dihydrothieno[3,4-d]pyrimidin-4(1H)-ones has been found and studied. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:104–111, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20181     

Crystal Structures of 5-Nitro- and 5-Ethoxycarbonyl-Substituted 6-Phenyl-4-(3-fluorophenyl)-3,4-dihydro-(1H)-pyrimidin-2-ones

The crystal structures of 5-nitro- and 5-ethoxycarbonyl-substituted 6-phenyl-4-(3-fluorophenyl)-3,4-dihydro-(1H)-pyrimidin-2-ones were determined by X-ray diffraction analysis. Conformational peculiarities of the structures have been revealed and compared with data for other biologically active dihydropyrimidinones.     

Five-membered 2,3-dioxo heterocycles: LIV. Double spiro heterocyclization of methyl 1-aryl-3-benzoyl-4,5-dioxo-4,5-dihydro-1<Emphasis Type="Italic">H</Emphasis>-pyrrole-2-carboxylates with 3-arylamino-5,5-dimethylcyclohex-2-en-1-ones

Methyl 1-aryl-3-benzoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates reacted with 3-arylamino-5,5-dimethylcyclohex-2-en-1-ones in boiling benzene to give the corresponding 1,1′-diaryl-3′-benzoyl-4′-hydroxy-6,6-dimethyl-1,1′,2,4,5,5′,6,7-octahydrospiro[indole-3,2′-pyrrole]-2,4,5′-triones and 1′-aryl-4-arylamino-3-benzoyl-6′,6′-dimethyl-1′,2′,4′,5′,6′,7′-hexahydro-5H-spiro[furan-2,3′-indole]-2′,4′,5-triones whose structure was proved by X-ray analysis.     

Synthesis and reactions of 1-R-3-benzoyl-5-ethoxycarbonyl-6-oxo-1,2,3,6-tetrahydropyridine-2-thiones

Cycloacylation of N-R-3-oxo-3-phenylpropanethioamides by diethyl ethoxymethylenemalonate occurs selectively to form 1-R-3-benzoyl-5-ethoxycarbonyl-6-oxo-1,2,3,6-tetrahydropyridine-2-thiones which are convenient starting materials for the synthesis of bi-and tricyclic hetero systems including the previously unknown 9-R-7-ethoxycarbonyl-5-phenyl-8,9-dihydropyrido[2,3-d][1,2,4]triazolo[1,5-a]-pyrimidin-8-ones. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1660–1669, November, 2007.     

Photochemistry of 4(3H)-pyrimidin-4-ones. Formation of medium-ring lactams

Upon irradiation, 4(3H)-pyrimidin-4-one(1) afforded a di-imine derivative(2) which, when hydrolyzed in an acidic methanol solution, gave N-methyl acetoacetamide(3). On the other hand, the fused 4(3H)-pyrimidin-4-ones, (4) and (5), gave medium-ring lactams(6) and (7), which were hydrolyzed in an acidic methanol solution to give (8) and (9), respectively.     

COPPER-CATALYSED REARRANGEMENT OF 4-SUBSTITUTED-2,3-1H-BENZOXAZINE-1-THIONES

Abstract

4-Substituted-2,3-1H-benzoxazine-1-thiones were prepared by the treatment of the corresponding benzoxazine-1-ones with P₂S₅. The thermal rearrangement of 4-substituted-2.3-1H-benzoxazine-1-thiones, catalysed by metallic copper, yielded 4-substituted-2.3-1 H-benzthiazine-1-ones.     

Solution-phase parallel synthesis of 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones

Practical and efficient parallel methods have been developed for the synthesis of 7,8-disubstituted 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones and 3,7,8-trisubstituted 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones. This benzothiazepin-4(5H)-one skeleton possesses three or four diversity points. Furthermore, three novel tricycles integrating a benzothiazepin-4(5H)-one scaffold with other privileged structures, such as benzimidazole, benzimidazolone, and thio-benzimidazole, were also developed. The synthetic strategy provides an efficient way to access the benzothiazepinone core, starting from commercially available 1,5-difluoro-2,4-dinitrobenzene (DFDNB), and also allows further derivation of the strategically anchored functionalities.     

Syntheses of optically active tetrahydro-1H-pyrrolo[1,2-a]imidazol-2-ones and hexahydroimidazo[1,2-a]pyridin-2(3H)-ones

The reactions of (2S)-2-amino-2-substituted-N-(4-nitrophenyl)acetamides 16a-c, succindialdehyde (13), and benzotriazole afforded enantiopure (3S,5R,7aR)-5-(1H-1,2,3-benzotriazol-1-yl)-3-substituted-1-(4-nitrophenyl)tetrahydro-1H-pyrrolo[1,2-a]imidazol-2-ones 17a-c, which were converted by sodium borohydride into (3S,7aR)-3-substituted-1-(4-nitrophenyl)tetrahydro-1H-pyrrolo[1,2-a]imidazol-2-ones 18a-c. Chiral (2S)-2-amino-2-substituted-N-(4-methylphenyl)acetamides 12a-d, easily prepared in two steps from N-Boc-alpha-amino acids 10a-d, similarly reacted with glutaraldehyde (20) and benzotriazole to generate 5-benzotriazolyl-3-substituted-hexahydroimidazo[1,2-a]pyridin-2(3H)-ones 21a-d, which were converted by sodium borohydride directly into optically active 3-substituted-hexahydroimidazo[1,2-a]pyridin-2(3H)-ones 22a-d.     

Synthesis of 3-substituted-3,4-dihydro-2H-1,3-benzothiazin- 2-ones via a highly regioselective palladium-catalyzed carbonylation of 2-substituted-2,3-dihydro-1,2-benzisothiazoles

A novel synthesis of 3-substituted-3,4-dihydro-2H-1,3-benzothiazin-2-ones is described herein. The strategy relies on a highly regioselective palladium-catalyzed carbonylation of 2-substituted-2,3-dihydro-1,2-benzisothiazoles to give the corresponding 3,4-dihydro-2H-1,3-benzothiazin-2-one derivatives in good to excellent yields.