Synthetic studies on diuretics. 5-(3,3-N,S-substituted-2-propenoyl)-2,3-dihydro-2- benzo[b]furancarboxylic acids

6,7-Dichloro-2,3-dihydro-2-benzo[b]furancarboxylic acid derivatives having a 3,3-N,S-disubstituted-2-propenoyl group at the 5-position were prepared by alkylation of 5-(thiocarbamoyl)acetyl derivatives of the 2,3-dihydro-2-benzo[b]furancarboxylic acid ester or by acetal exchange reaction of 5-[3,3-bis(alkylthio)-2-propenoyl] derivatives. Synthesis of 5-[4 and/or 5-(di)substituted-4-thiazolin-2-ylidene]acetyl-2,3- dihydro-2-benzo[b]furancarboxylic acids was also achieved by the reaction of 2-halo-1-methoxyethyl isothiocyanate with the 5-acetyl derivative in the presence of base or through sulfide contraction of 2-[[6,7-dichloro-2-methoxycarbonyl-2,3-dihydrobenzo[b]furan-5-yl) carbonyl)-methylthio]thiazolium bromide. Some of the compounds which were synthesized showed potent natriuretic activities in rats and mice. The structure-activity relationship is also discussed.     

Synthesis of 3-amino derivatives of benzo[b]furo[2,3-c]pyridines

The reaction of 1,7-dimethyl-3(2H)-benzo[b]furo[2,3-c]pyridone with phosphoric acid amides gave 1,7-dimethyl-3-dimethylamino (morpholino)benzo[b]furo[2,3-c]pyridines. A method for the synthesis of 3-amino derivatives of 4-nitrobenzo[b]furo[2,3-c]pyridines, which consists in heating 1,7-dimethyl-4-nitro-3(2H)-benzo[b]furo[2,3-c]pyridone with hexamethyldisilazane and secondary or primary amines in pyridine, was developed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1552–1555, November, 1991.     

Triazènes et benzotriazines dérivés de sucres

Sugar triazenes and benzotriazines Several triazenylsugars have been prepared, generally in good yields, by treating an amino sugar with a substituted benzenediazonium salt. The triazenylsugars bearing a hydrogen atom on the triazenyl group are acetylated on the nitrogen atom closest to the glycosyl moiety (N(1)), even when the proton exchanged sites between N(1) and N(3). When an acetyl or a methoxycarbonyl group was present in the ortho position of the benzene ring cyclization took place leading to a 3,4-dihydro-4-methylidene-1,2,3-benzo[d]triazine or a 3,4-dihydro-1,2,3-benzo[d]triazin-4-one respectively.     

Synthesis of some 5H-benzo[a]phenoxazin-5-one derivatives

The substituted 6-bromo and 6-chloro-5H-benzo[a]phenoxazin-5-ones, prepared by condensation of substituted 2-aminophenols with 2,3-dibromo or 2,3-dichloro-1,4-naphthoquinone in methanolic potassium hydroxide solution, have been dehalogenated to substituted 5H-benzo[a]phenoxazin-5-ones in the presence of sodium hydrosulfite dissolved in aqueous pyridine under nitrogen atmosphere.     

Reactions with benzo[b]thiophene-2,3-diones I: Synthesis of 2,3-dihydroxy-2,3-diaryl(aralkyl)benzo[b]thiophene derivatives

Benzo[b]thiophene-2,3-diones ( 1 ) react with Grignard reagents to yield 2,3-dihydroxy-2,3-diaryl(aralkyl)benzo[b]-thiophenes ( 2 ). The latter compounds yield 3,3-diaryl(aralkyl)-benzo[b]thiophene-2-ones ( 3 ) by pinacolone rearrangement. Treatment of 3 by hot ethanolic sodium hydroxide solution yields the corresponding carboxylic acids by hydrolytic heteroring opening.     

Synthesis of 3-(arylamino)-5-bromo-2-phenyl-2,3-dihydro-2λ5-benzo[d][1,2]-oxaphosphol-2-oxides

An efficient synthesis of cis-3-(arylamino)-5-bromo-2-phenyl-2,3-dihydro-2λ⁵-benzo[d][1,2]-oxaphosphol-2-oxides 4a–h is described involving a three-component reaction of dichlorophenylphosphine (2), 5-bromosalicylaldehyde (1), and different substituted aromatic primary amines (3) in anhydrous benzene. The product structures were characterized by IR and NMR spectral data.     

Synthesis of New Cyclopenta[<Emphasis Type="Italic">b</Emphasis>]quinoline Derivatives

A series of new 11-(R-phenyl)-8,9-dihydro-7H-benzo[f]cyclopenta[b]quinolin-10(11H)-ones and 7,14-bis(R-phenyl)-2,3,9,10,11,14-hexahydrocyclopenta[2,3]quinolino[8,7-h]cyclopenta[b]quinoline-1,8(4H,7H)-diones were synthesized by three-component condensation of naphthalen-2-amine or naphthalene- 1,5-diamine with substituted benzaldehydes and cyclopentane-1,3-dione in one step through intermediate formation of unstable arylaminoketoenol.     

Condensed isoquinolines. 21. Condensation of <Emphasis Type="Italic">o</Emphasis>-bromomethylphenylacetonitrile with substituted anthranilic acids

The reaction of substituted anthranilic acids and esters with o-bromomethylphenylacetonitrile give 2,3-R,R¹-7,12-dihydro-5H-isoquino[2,3-a]quinazolin-5-one hydrobromides. It was found that 7,12-dihydro-5H-isoquino[2,3-a]quinazolin-5-ones can exist in the two tautomeric imine and enamine forms. The tautomeric equilibrium position depends on the nature and position of the substituent in the quinazoline fragment. The borohydride reduction, oxidation, and reaction of 2,3-R,R¹-7,12-dihydro-5H-isoquino[2,3-a]quinazolin-5-ones with electrophilic reagents has been studied. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 562–573, April, 2007.     

The synthesis of propellance compounds from 2,3-disubsituted indoles and o-benzoquinones

The reaction of 2,3-dihydro-1H-cyclopent[b]indole 3 and 1,2,3,4-tetrahydrocarbazole 4 with substituted o-benzoquinones yielded [4.3.3]- and [4.4.3]propellanes, respectively. The physical and chemical properties of the propellane compounds were investigated and a mechanism for the formation of the propellane compounds was discussed.     

Synthesis and Biological Evaluation of Some Novel N,N ′-Bis-(1,2,4-Triazin-4-Yl)Dicarboxylic Acid Amides and Some Fused Rings with 1,2,4-Triazine Ring

Some of novel N , N '-bis-(1,2,4-triazin-4-yl)dicarboxylic acid amides ( 2-5 ) and thiadiazolo[2,3- b ][1,2,4]triazin-7-yl carboxylic acid derivatives ( 6 , 7 ) were prepared by heating 4-amino-6-methyl-5-oxo-3-thioxo-2,3,4,5-tetrahydro-1,2,4-triazine ( 1 ) with different dicarboxylic acids (oxalic, malonic, fumaric, maleic, succinic, and phthalic acids respectively) in POCl 3 . Refluxing 1 with 1-chloro-2,4-dinitrobenzene in DMF yielded 3-methyl-6-nitro-10 H -benzo[1,2,4]thiadiazino[2,3- c ][1,2,4]triazin-4-one ( 8 ). Condensation of 1 with 2,4-pentandione in refluxing acetic acid furnished 6-methyl-4-(1-methyl-3-oxobut-1-enylamino)-3-thioxo-3,4-dihydro-2 H -[1,2,4]triazin-5-one ( 9 ). 3,8-D imethyl[1,2,4] triazino[3,4- b ][1,3,4]thiadiazine-4,7-dione ( 11 ) was prepared by refluxing 1 with 2-bromopropionyl bromide in anhydrous benzene to afford the corresponding N -acetylated derivative 10 , which was cyclized by using triethylamine. Also, some triazinylquinazolinones 13a , b were obtained by fusion of 1 with 6-bromo(and/or 6,8-dibromo)-2-methyl-3,1-benzoxazin-4 H -ones.     

A new course of the Perkin cyclization of 2-(2-formyl-6-methoxyphenoxy)alkanoic acids. Synthesis of 2-alkyl-7-methoxy-5-nitrobenzo[b]furans

2-Alkyl-7-methoxy-5-nitrobenzo[b]furan, 2-alkyl-9-methoxy-7-nitro-3-oxo-2,3-dihydro-5H-benzo[e][1,4]-dioxepin-5-yl acetate and 2-alkyl-5-hydroxy-9-methoxy-7-nitro-5H-benzo[e][1,4]-dioxepin-3-one were formed as a result of the cyclization of 2-(2-formyl-6-methoxy-4-nitrophenoxy)alkanoic acids under classical Perkin reaction conditions. The products were characterized by spectroscopic methods and the mechanism of the cyclization is discussed.     

Synthesis and antimicrobial agents of thiazolidinone derivatives from benzocyclohepetenone

A series of benzosuberone coupled piperazin-1-yl thiazolidin-4-one derivatives 6a-j were synthesized from 3-(2-[9-chloro-2,3-dimethyl-6,7-dihydro-5H-benzo[7]annulen-8-yl]-4-oxothiazolidin-3-yl)propanoic acid ( 4 ) and substituted piperazines/secondary amines 5a-j using 1-hydroxy benzotriazole, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and triethyl amine in good yields and their structures were characterized by ¹H NMR, ¹³C NMR, IR, and Mass spectra. The newly synthesized compounds were evaluated for their antimicrobial activity against bacterial strains and a fungal strain. Compounds 6f and 6g were indicated promising and broad spectrum antibacterial activity.     

The synthesis of β-carboline derivatives-II A synthesis of some benz-indolo[2,3-a]pyridocolinium salts, including sempervirine

A novel synthetic method for β-carboline derivatives, described in the preceding paper, is now applied to the syntheses of 6,7-dihydro-12H-benz[f]indolo[2,3-a]pyridocolinium salt, 8,9-dihydro-14H-benz[h]indolo-[2,3-a]pyridocolinium salt and sempervirine. In the course of synthesis of sempervirine, 2-[2-(3-indolyl)ethyl]-3-chloro-5,6,7,8-tetrahydro-isoquinolinium bromide is obtained as an intermediate, lending strong support for the mechanism previously proposed.     

Photocyclization of 2-[1]benzothien-3-yl)-3-phenylpropenoic acids

Photocyclization of the substituted 2-([1]benzothien-3-yl)-3-phenylpropenoic acids 3a-c in the presence of iodine and air in a benzene-cyclohexane mixture afforded a separable mixture of three compounds, benzo[b]naphtho[2,1-d]thiophene-6-carboxylic acids 4a-c , 6H-benzo[b]naphtho[2,3-d]thiopyran-6-ones 5a-c , and 10-methoxy-2-methyl-6H-benzo[b]naphtho[2,3-d]pyran-6-one ( 6 ).     

Nouvelles voies d'accès à des aryl-4 thiéno[2,3-c]pyridines et à des aryl-7 thiéno[3,2-c]pyridines

4-Arylthieno[2,3-c]pyridines and 7-arylthieno[3,2-c]pyridines have been prepared by heating in polyphosphoric acid 2-(2-thenylamino>l-arylethanols or propanols and 2- 3-thenylamino>l-arylethanols or propanols, respectively.) Under the Beckmann rearrangement conditions, oximes of 4-aryl-4,5-dihydro-6H-cyclopenta[b]thiophen-6-one lead to 4-aryl-4,5- dihydro-6H-thieno[2,3-c]pyridin-7-one.     

Synthese de dihydro-6,7 benzo-b [1H] azonines par extension de cycle de dihydro-4,5 benzo-b [1H] azepines

Activated acetylnic reagents add to heterocyclic enamines 4,5-dihydro-1H-benzo[b]azepines and by electrocyclisation, give 6,7-dihydro-1H-benzo[b]azoninines. The structure of those new heterocycles is demonstrated by mass spectra, ¹H and ¹³C nmr.     

4-(10-Methyl-10H-phenothiazin-3-yl)-1,4-dihydropyridines, 4,5-dihydroindeno[1,2-<Emphasis Type="Italic">b</Emphasis>]-and 5,5-dioxo-4,5-dihydrobenzo-thieno[3,2-<Emphasis Type="Italic">b</Emphasis>]pyridines

Different modifications of the Hantzsch synthesis using 10-methyl-10H-phenothiazine-3-carbaldehyde gave 4-(10-methyl-10H-phenothiazin-3-yl)-substituted 1,4-dihydropyridine-3,5-di-, 5-oxo-4,5-dihydro-1H-indeno[1,2-b]pyridine-, and 5,5-dioxo-4,5-dihydro-1H-5λ⁶-benzo[4,5]thieno[3,2-b]pyridine-3-carboxylic esters. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 280–288, February, 2007.     

Nucleophilic substitution reactions in 2-chloropyridines and 2,5-dioxo-1,2,5,7-tetrahydro-1H-furo[3,4-b]pyridines

3-Cyano- and 3-carbamoyl-2-chloropyridines react with hydrazine hydrate to form substituted 3-amino-1H-pyrazolo[3,4-b]pyridines and 3-oxo-2,3-dihydro-1H-pyrazolo[3,4-b]pyridines. Hydrazine hydrate reacts with 3-carbamoyl-2-chloro-5-oxo-5,7-dihydrofuro[3,4-b]pyridine to form substituted 3,5-dioxo-2,3,5,7-tetrahydro-1H-pyrazolo[3,4-b]furo[3,4-e]pyridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1218–1222, September, 1992.     

Polysubstituted 2,3-dihydrofuro[2,3-b]pyridines and 3,4-dihydro-2H-pyrano[2,3-b]pyridines via microwave-activated inverse electron demand Diels-Alder reactions

Polysubstituted 2,3-dihydrofuro[2,3-b]pyridines and 3,4-dihydro-2H-pyrano[2,3-b]pyridines have been synthesized from 1,2,4-triazines using the inverse electron Diels-Alder reaction. For this purpose, 3-methylsulfanyl-1,2,4-triazines were reacted with several nucleophiles allowing the formation of appropriately substituted alkynes to undergo the intramolecular inverse electron demand Diels-Alder reaction. Sealed-tube microwave activation of the cycloaddition reaction has proved to be very efficient and allowed shorter reaction times. This strategy enabled an efficient synthesis of 3-hydroxy-2,3-dihydrofuro[2,3-b]pyridines and 4-hydroxy-3,4-dihydro-2H-pyrano[2,3-b]pyridines with several points of diversity on the bicyclic scaffold.     

Preparation of novel heterocyclic systems from isatoic anhydrides

Isatoic anhydride ( 1a ) and 5-chloroisatoic anhydride ( 1b ) were treated with 2-(1-methylhydrazino)ethanol ( 2 ) to produce 2-aminobenzoic acid 2-(2-hydroxyethyl)-2-methylhydrazide ( 3a ) and its 5-chloro analog 3b , respectively. Treatment of 3a and 3b with carbon disulfide gave, respectively, 2,3-dihydro-3-[(2-hydroxyethyl)methylamino]-2-thioxo-4-(1H)quinazolinone ( 4a ) and its 6-chloro analog 4b . Compounds 4a and 4b afforded 5,6-dihydro-5-methyl-2-thioxo-4H,8H-[1,3,5,6]oxathiadiazocino[4,5-b]quinazolin-8-one ( 5a ) and its 10-chloro analog 5b , respectively, upon treatment with thiophosgene. Compound 5a could be produced directly from 3a and thiophosgene. Treatment of 4a and 4b with trifluoroacetic anhydride followed by potassium carbonate gave 3,4-dihydro-4-methyl-2H,6H-[1,3,4]thiadiazino[2,3-b]quinazolin-6-one ( 7a ) and its 8-chloro analog 7b , respectively. Treatment of 4a with thionyl chloride also gave 7a , but 4b and thionyl chloride afforded a mixture of 7b and 8-chloro-3,4-dihydro-4-methyl-2H,6H-[1,3,4]oxadiazino[2,3-b]quinazolin-6-one ( 10 ). The dimethyl analogs of 4a and 4b ( 13a and 13b ) upon treatment with thiophosgene afforded 3,4-dihydro-2,2,4-trimethyl-2H,6H-[1,3,4]oxadiazino[2,3-b]quinazolin-6-one ( 14a ) and its 8-chloro analog 14b , respectively.