A step forward in the field of drug design: 1,5-benzothiazepines and their nucleosides

(±)cis-2-(4-methoxyphenyl)-3-hydroxy/methoxy-6-methoxy/8-methoxy-2,3-dihydro-1,5-benzothiazepin-4-[5H/5-chloroacetyl/5-(4′-methylpiperazino-1′)acetyl]-ones and nucleosides viz; (±)cis-2-(4-methoxyphenyl)-3,6-dimethoxy-2,3-dihydro-1,5-benzothiazepin-4-[5-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)]-one and (±)cis-2-(4-methoxyphenyl)-3,8-dimethoxy-2,3-dihydro-1,5-benzothiazepin-4-[5-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)]-one have been synthesized by the condensation of substituted-2-aminobenzenethiols with methyl (±)trans-3-(4-methoxyphenyl)glycidate in xylene and by stirring the 3-methoxy derivative of 1,5-benzothiazepin-4(5H)-ones with sugar namely β-D-ribofuranosyl-1-acetate-2,3,5-tribenzoate at 155–160 °C in vacuo for 10 hours, respectively. The synthesized compounds have been characterized by the elemental analyses and spectral data and screened for their antimicrobial activity.     

1,3-Dipolar cycloaddition of phthalazinium ylides to 5-arylidene-2-spirocyclohexane-1,3-dioxane-4,6-diones

Tetrahydrospiropyrrolo[2,1-a]phthalazines were synthesized by the reaction of 5-arylidene-2-spirocyclohexane-1,3-dioxane-4,6-diones with phthalazinium ylides. One of the reaction products, viz., 3-ethoxycarbonyl-2-(4-methoxyphenyl)-2′,2′-pentamethylene-1,2,3,10b-tetrahydrospiro[pyrrolo[2,1-a]phthalazine-1,5′-[1,3]dioxane]-4′,6′-dione, was studied by X-ray diffraction. The spectroscopic characteristics of the reaction products are discussed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2362–2365, October, 2005.     

Synthesis of [1,5-A]Pyrimidinone Ring Derivatives

Cyclodehydrogenation of the benzalhydrazino derivatives 5 and 6 gave 6-cyano-7-(4-methoxyphenyl)- 2-phenyl-5-oxo-1,2,4-triazolo[1,5-a]pyrimidine (8) and 6-cyano-7-(4-methoxyphenyl)-4-methyl-2-phenyl- 5-oxo-1,2,4-triazolo[1,5-a]pyrimidine (9) respectively. Melhylation, acetylation and benzylation of 8 gave the corresponding N-methyl, acetyl and benzyl derivatives 10-12 . Methylation of 5 with dimethylsulfate gave 2-benzalhydrazino-5-cyano-3-methyl-6-(4-methoxyphenyl)-3,4-dihydropyrimidin-4-one (6) , of which the reaction with acetic anhydride in pyridine afforded the N-acetylbenzalhydrazino derivative 15 . The latter was also prepared from acetylation of 5 followed by medthylation with iodomethane. Acetylation of 5 with boiling acetic anhydride afforded the diacetyl derivative 16 , whereas its benzylation gave the mono-N-benzyl derivative 14 .     

Transformations of stereoisomeric 2-chloro-3-R-pentane-1,5-diones in reaction with phenylhydrazine

Monophenylhydrazones were prepared from three monochloro derivatives of arylaliphatic 1,5-diketones, and some their transformations were investigated. The monophenylhydrazones formed regiospecifically, and the direction of the reaction was governed by the substituent attached to C³ atom in the initial chlorodiketones. Formerly unknown products of transformations suffered by monophenylhydrazones obtained were described: 2-amino-1,3-diphenyl-3-(2-phenylindolyl-3)-propan-1-one, 3-benzoyl-2,4,6-triphenyl-2,3,4,5-tetrahydropyridazine, and 3-methyl-1,5-diphenyl-5-phenylazopent-4-en-1-one.     

Synthesis and Properties of 1,5-Dimethyltricyclo[3.3.0.02,8]octane- and 1,5-Dimethyltetracyclo[3.3.0.02,804,6]octane Derivatives

The synthesis of 1,5-dimethyltricyclo[3.3.0.0^2,8]octane-3,7-dione ( 2 ), 1,5-dimethyltetracyclo[3.3.0.0^2,80^4,6]-octane-3,7-dione ( 3 ), the corresponding dienes 5 and 6 as well as the mixed enones 13 – 15 is reported. Using He( I ) photoelectron spectroscopy (PE) as a tool, a considerable interaction between the n orbitals on the O-atoms and the σ frame in 2 and 3 as well as of the double bonds in 5 and 6 and the σ frame is found. These interactions are also traced back by the electronic absorption spectra of these compounds. The molecular structures of 2 and 3 have been investigated by X-ray analysis.     

Photocyclization of 2-chloro-substituted 1,3-diarylpropan-1,3-diones to flavones

The photochemical behavior of 2-halo-substituted 1,3-diarylpropan-1,3-dione strongly depends on the nature of the halogen atom bonded and the presence of electron-donor groups on the phenyl ring. In the case of 2-chloro-1,3-diphenylpropan-1,3-dione and 1-(3,5-dimethoxyphenyl)-3-phenylpropan-1,3-dione, cyclization to flavones was the sole reaction pathway, whereas in the case of 2-chloro-1,3-di(4-methoxyphenyl)propan-1,3-dione, only products derived from alpha-cleavage were observed. 2-Fluoro derivatives of 1,3-diarylpropan-1,3-diones were photostable; on the other hand, 2-chloro-2-fluoro derivates resulted in 3-fluoroflavones.     

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.     

Synthesis of 1,3-dialkylpyrazolo [1,5-a]-1,3,5-triazine-2,4-diones isomers of 1,3-dialkylxanthines

The synthesis of a new series of alkylxanthine analogs containing a bridgehead nitrogen atom is reported. 1,3-Dialkylpyrazolo[1,5-a]-1,3,5-triazine-2,4-diones, were prepared by the treatment of 3-methylpyrazolo[1,5-a]-1,3,5-triazine-2,4-dione (3) with the corresponding alkyl iodide. Similarly, the reaction of 3-methyl-7-phenylpyrazolo[1,5-a]-1,3,5-dialkyl-7-phenylpyrazolo[1,5-a]-1,3,5-triazine-2,4-diones. The starting materials, 3 and 17 , were prepared via the reaction of an appropriate 3-aminopyrazole with ethoxycarbonyl isothiocyanate. Several 8-bromo derivatives were prepared by direct bromination of the 1,3-dialkylpyrazolo[1,5-a]-1,3,5-triazine-2,4-diones.     

First synthesis of 1,5-diazabicyclo[3.1.0]hexane complexes with cadmium salts

Complexes of bicyclic diaziridines 6,6′-bi(1,5-diazabicyclo[3.1.0]hexane) (L ¹ ) and 6-(4-methoxyphenyl)-1,5-diazabicyclo[3.1.0]hexane (L ² ) with the salts Cd(NO₃)₂ · 4H₂O and Cd(ClO₄)₂ · 6H₂O have been synthesized. The fact of complexation has been established by cyclic voltammetry. The crystal structure of complex L ¹ with Cd(NO₃)₂ (the coordination number of cadmium is 8) has been studied by X-ray diffraction.     

Synthesis of 4-substituted azepino[3,4-b]indole-1,5-diones

Mono- or dibromo derivatives 2 and 3 were prepared by an efficient two-step route from 10-methyl-azepino[3,4-b]indole-1,5-dione 1. Elimination reaction on 2 gave access to 4-bromo-10-methyl-2H,10H-azepino[3,4-b]indole-1,5-diones 4. Finally, 4-substituted 10-methyl-2H,10H-azepino[3,4-b]indole-1,5-diones 6-14 were synthesised in good yields from 4 via palladium-mediated cross-coupling reactions.     

A New and simple synthesis of 2-aryl-4,9-dihydrocyclohepta[b]pyran-4,9-diones

3-Acetyltropolone ( 1 ) reacted with 2-methoxybenzaldehyde ( 2a ) in the presence of ethyl orthoformate and perchloric acid to afford 2-(2-methoxyphenyl)-4,9-dihydrocyclohepta[b]pyran-4,9-dione ( 3a ). The reactions with 3,4-dimethoxybenzaldehyde ( 2b ), vanillin ( 2c ), and piperonal ( 2d ) gave respectively the corresponding products 3b-d . The reaction with benzaldehyde ( 2e ) gave uncyclized 3-cinnamoyltropolone ( 4 ).     

3-α-Halocarbonyl derivatives of pyrazolo[1,5-a] benzimidazole and their reactions

3-(-haloacyl)-2,4-dialkylpyrazolo[1,5-a]benzimidazoles can be obtained either by brominating 3-acetylpyrazolo[1,5-a]benzimidazoles with bromine in acetic acid, or by acylating the 3-unsubstituted pyrazolobenzimidazoles with haloacetic halides. Halogenation of 3-acetylpyrazolo[1,5-a]benzimidazoles with bromine in acetic acid in the presence of sodium acetate, and bromination with N-bromosuccinimide or 1-chlorobenzotriazole, result in deacylation to give 3,6(7)-dibromo- and 3-chloropyrazolo[1,5-a]benzimidazoles. The mono- and trihaloketones obtained have been used to prepare the corresponding aminoketones, the 3-carboxylic acid, and its derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 43–48, January, 1988.     

Synthesis,characterization and antitumour activities of some synthetic curcuminoid analogues and their copper complexes

The cytotoxic and antitumour activities of four curcuminoid analogues, namely 1,7-diphenyl-1,6-heptadiene-3,5-dione (HL¹), 1,7-bis(4-methoxyphenyl)-1,6-heptadiene-3,5-dione (HL²), 1,7-bis(3,4-dimethoxyphenyl)-1,6-heptadiene-3,5-dione (HL³), 1,7-bis(3,4-dihydroxyphenyl)-1,6-heptadiene-3,5-dione (HL⁴) and their Cu^II complexes were investigated.The Cu complexes were found to be more active as antitumour agents compared to the free curcuminoids, in both in vitro studies and in increasing the life span of tumour bearing mice. The synthesis and characterization of the curcuminoid analogues and their Cu^II chelates employing u.v., i.r., ¹ H-n.m.r., e.s.r. and mass spectral studies are also included in this report.     

1,3,5-Triaryl-2-penten-1,5-dione anchored to insoluble supports as heterogeneous chromogenic chemosensor

N-Allyl substituted 1,5-diphenyl-3-(4-N-methylaminophenyl)-2-penten-1,5-dione (1a) has been immobilized on a polystyrene backbone, on the surface of mercaptopropyl-functionalized silica or inside the cavities of zeolite NaY. These solids either in suspension or in films act as chemosensors of Fe³⁺ and other strong Lewis acid metal ions such as Cu²⁺ and Pb²⁺ in buffered water or ethanol. Brönsted acids in low pH aqueous solutions also produce the response of the sensor. For sensing of Fe³⁺, depending on the loading of 1a (typically from 2.5 to 0.5 wt%) the solids can test from 10⁻² to 10⁻⁴ M aqueous solutions. The time response can vary from tens of minutes to below a minute depending on hydrophilic/hydrophobic nature of the support and also on the 1a loading. The solid sensor was reused up to 10 times by regenerating after every use the initial form with NaAcO treatment.     

Unexpected photochemical transformation of imidazole derivatives containing the 5-hydroxy-2-methyl-4H-pyran-4-one moiety. Environmentally friendly method for the synthesis of substituted imidazo[1,5-a]pyridine-5,8-diones

An unexpected photochemical transformation of imidazole derivatives containing the 5-hydroxy-2-methyl-4H-pyran-4-one moiety was discovered, which led to the synthesis of previously unknown imidazo[1,5-a]pyridine-5,8-dione derivatives. The structures of imidazole and imidazo[1,5-a]pyridine-5,8-dione derivatives were unambiguously determined by X-ray diffraction analysis.     

Absolute Conformation and Configuration of (2S, 3S)-3-Acetoxy-5-(dimethylaminoethyl)-2-(4-methoxyphenyl)-2,3-dihydro-1,5-benzothiazepin-4(5H)-one Chloride (Dilthiazem Hydrochloride)

Resolution of racemic cis-3-(2-aminophenylthio)-2-hydroxy-3-(4-methoxyphenyl) propionic acid ( 2 ) via the cinchonidine salt 3 , and brucine salt 4 , isolation of the calcium salts (+)- and (?)- 5 , as well as their cyclization to enantiomeric 1,5-benzothiazepines (+)- and (?)- 1 , are described. X-Ray single-crystal analysis reveals (2S, 3S) absolute configuration of (+)- 1 on the basis of tentative comparison of CD data with those for the 1,4-benzodiazepine derivative (+)- 8 of known absolute configuration.     

Synthesis of carbamoylpyridine and imidazo[1,5-a]pyridin-1,3-diones via ortho-acetalhydantoin intermediates

A new method for preparing carbamoylpyridine and imidazo[1,5-a]pyridin-1,3-dione rings from an ortho-acetalmethylideneimidazolidin-2,4-dione is described.     

Synthesis of 8,9-dihydro[1,2,4]triazolo[1,5-a]-quinazolin-6(7H)-one derivatives

Regioselectivity of the reactions of 1H-1,2,4-triazol-3-amines with 2-acyl-5,5-dimethylcyclohexane-1,3-diones and 2-dimethylaminomethylidene-5,5-dimethylcyclohexane-1,3-dione was studied. In all cases, the products were substituted 8,9-dihydro[1,2,4]triazolo[1,5-a]quinazolin-6(7H)-ones whose structure was determined by ¹H and ¹³C NMR spectroscopy.     

Ultraviolet spectra of 2-phenyl-4- and 2-phenyl-5-azaindan-1, 3-diones

The UV spectra of 2-phenyl-4-azaindan-1, 3-dione (I), 2-phenyl-5-azaindan-1, 3-dione (II), and their N-methylbetaines are investigated. 2×10^–5 M aqueous alcoholic solutions of 2-phenyl-4-azaindan-1, 3-dione (I) contain the anionic form (IA), and in solutions of 2-phenyl-5-azaindan-1, 3-dione (II) the betaine form (IIB) is also in equilibrium with the anion (IIA). Solutions of I and II in 0.1 M sulfuric acid are characterized by a wide and rather intense absorption band at about 500 m, indicating the presence of a betaine form (IB and IIB). In 2M hydrochloric acid solution 2-phenylazaindan-1, 3-diones and their N-methylbetaines (III and IV) are protonated at the oxygen atom, giving the enol forms of the N-protonated or corresponding N-methylated 2-phenylazaindandiones.     

1,3,5-Triarylpent-2-en-1,5-diones for the colorimetric sensing of the mercuric cation

The 1,3,5-triarylpent-2-en-1,5-dione group selectively undergoes cyclisation and changes its colour from yellow to magenta upon coordination of Hg2+ on a remote site.