Cyclization of trifluoro-<Emphasis Type="Italic">N</Emphasis>-(prop-2-yn-1-yl)methanesulfonamides to <Emphasis Type="Italic">N</Emphasis>-(hydroxymethyl)-1,2,3-triazoles

Three-component heterocyclizations of trifluoro-N-(prop-2-yn-1-yl)methanesulfonamide, trifluoro-N-pheny-N-(prop-2-yn-1-yl)methanesulfonamide, and trifluoro-N,N-di(prop-2-yn-1-yl)methanesulfonamide with formaldehyde and sodium azide afforded N-{[2-(hydroxymethyl)-2H-1,2,3-triazol-4-yl]methyl}-, N-{[2-(hydroxymethyl)-2H-1,2,3-triazol-4-yl]methyl}-N-phenyl-, and N,N-bis{[2-(hydroxymethyl)-2H-1,2,3-triazol-4-yl]methyl}trifluoromethanesulfonamides as the major products together with minor 1-(hydroxymethyl)-1H-1,2,3-triazole isomers.     

Regioselectivity in the reactions of <Emphasis Type="Italic">N</Emphasis>-(polychloroethylidene)-sulfonamides with 1<Emphasis Type="Italic">H</Emphasis>-pyrrole and 1-methyl-1<Emphasis Type="Italic">H</Emphasis>-pyrrole

N-(2,2,2-Trichloroethylidene)arenesulfonamides react with 1H-pyrrole and 1-methyl-1H-pyrrole to give the corresponding N-[2,2,2-trichloro-1-(1H-pyrrol-2-yl)ethyl]arenesulfonamides. The reaction of N-(2,2,2-trichloroethylidene)trifluoromethanesulfonamide with pyrrole leads to a mixture of 2-mono-and 2,5-disubstituted pyrroles, whereas in the reaction with 1-methyl-1H-pyrrole only the 2-substituted compound is formed. N-(2,2-Dichloro-2-phenylethylidene)-4-methylbenzenesulfonamide reacts with 1H-pyrrole to form N-[2,2-dichloro-2-phenyl-1-(1H-pyrrol-2-yl)ethyl]-4-methylbenzenesulfonamide, and its reaction with 1-methyl-1H-pyrrole gives a mixture of 2-and 3-monosubstituted derivatives. The results of quantum-chemical calculations of the initial reactants and products indicate that the process is orbital-controlled. A good agreement is observed between the experimental data and theoretical conclusions concerning the dependence of the reaction regioselectivity on the nature of substituents in the electrophile molecule.     

Chemistry of Iminofurans: XV. Decyclization of Ethyl 2-[5-Aryl-2-oxofuran-3(2<Emphasis Type="Italic">H</Emphasis>)-ylideneamino]-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylates by the Action of Secondary Amines

Ethyl 2-[5-aryl-2-oxofuran-3(2H)-ylideneamino]-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylates reacted with secondary amines to give 4-aryl-2-(thiophen-2-yl)-4-oxobutanamides, whereas their reaction with piperazine afforded N,N′-disubstituted piperazine derivatives regardless of the reactant ratio.     

Synthesis of novel 4<Emphasis Type="Italic">H</Emphasis>-furo[3,2-c]pyran-4-ones and 4<Emphasis Type="Italic">H</Emphasis>-furo[3,2-<Emphasis Type="Italic">c</Emphasis>]chromen-4-ones

It was found that the condensation of two equivalents of 4-hydroxy-6-methyl-2H-pyran-2-one or 4-hydroxycoumarin with arylglyoxals in boiling formic acid leads to 4H-furo[3,2-c]-pyran-4-ones or 4H-furo[3,2-c]chromen-4-ones, respectively.     

Polyfunctional imidazoles: XIII.<Superscript>1</Superscript> Addition and cyclization reactions of 1-aryl-4-chloro-5-(2-nitroethenyl)-1<Emphasis Type="Italic">H</Emphasis>-imidazoles with sulfur and nitrogen nucleophiles

1-Aryl-4-chloro-5-(2-nitroethenyl)-1H-imidazoles reacted with thiols and aromatic amines via Michael addition to give 5-[(1-arylsulfanyl)-2-nitroethyl)]-4-chloro-1H-imidazoles and N-[1-(1-aryl-4-chloro-1H-imidazol-5-yl)-2-nitroethyl]anilines, respectively. [2 + 3]-Cycloaddition of the title compounds to sodium azide afforded 4-(4-chloro-1H-imidazol-5-yl)-1H-1,2,3-triazoles.     

Synthesis and reactions of 3-(3-ethoxycarbonyl-1-phenyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-4-yl)propenic acid

The reaction of ethyl 4-formyl-1-phenyl-1H-pyrazole-3-carboxylate with the malonic acid led to the formation (2E)-3-(3-ethoxycarbonyl-1-phenyl-1H-pyrazol-4-yl)propenic acid. In reactions of this acid chloride with 4-amino-5-aryl(hetaryl)-4H-1,2,4-triazole-3-thiols were obtained ethyl 4-[(E)-2-{3-aryl(hetaryl)[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl}ethenyl]-1-phenyl-1H-pyrazoe-3-carboxylates, with 5-aryltetrazoles, ethyl 4-[(E)-2-(5-aryl-1,3,4-oxadiazol-2-yl)-ethenyl]-1-phenyl-1H-pyrazole-3-carboxylates, with 1-(2-hydroxy-3,5-dimethylphenyl) followed by the Baker-Venkataraman rearrangement and the cyclization, ethyl 4-[(E)-2-(6,8-dimethyl-4-oxo-4Hchromen-2-yl)ethenyl]-1-phenyl-1H-pyrazole-3-carboxylate.     

Electrophilic cyclization of <Emphasis Type="Italic">N</Emphasis>-allyl(propargyl)-5-amino-1<Emphasis Type="Italic">H</Emphasis>-pyrazole-4-carboxamides. Synthesis of 4-[(dihydro)oxazol-2-yl]-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-5-amines

N-Allyl-5-amino-1H-pyrazole-4-carboxamides in reactions with polyphosphoric acid, with N-halosuccinimides in chloroform, and with (chlorosulfanyl)benzenes in nitromethane in the presence of lithium perchlorate underwent cyclization involving the N-allylamide fragment to give 4-[5-methyl(halomethyl)-4,5-dihydrooxazol-2-yl]-1H-pyrazol-5-amines and 2-(5-amino-1H-pyrazol-4-yl)-5-[(arylsulfanyl)methyl]-4,5-dihydro-1,3-oxazolium perchlorates, respectively. Analogous reactions of N-propargyl-5-amino-1H-pyrazole-4-carboxamides with polyphosphoric acid afforded 4-(5-methyloxazol-2-yl)-1H-pyrazol-5-amines, and with (chlorosulfanyl) benzenes, 2-(5-amino-1H-pyrazol-4-yl)-5-[(arylsulfanyl)methylidene]-4,5-dihydro-1,3-oxazolium perchlorates.     

Alkylation of 1,2,4-triazole-3-thiols with haloalkanoic acid esters

Alkylation of 4,5-disubstituted 4H-1,2,4-triazole-3-thiols with methyl chloroformate and ethyl chloroacetate chemoselectively afforded the corresponding S-alkyl derivatives, whereas the alkylation of 5-benzyl-4-phenyl-4H-1,2,4-triazole-3-thiol with methyl 3-bromopropanoate gave an inseparable mixture of S- and N-alkylation products. Hydrazinolysis of S-(5-benzyl-4-phenyl-4H-1,2,4-triazol-3-yl) methyl carbonothioate involved anomalous cleavage with formation of the initial 4,5-disubstituted 1,2,4-triazole and methyl hydrazinecarboxylate.     

Atropisomeric <Emphasis Type="Italic">N</Emphasis>-acyl-<Emphasis Type="Italic">N</Emphasis>-(cyclopentenylphenyl)glycines in the synthesis of oxazolo[3,4-<Emphasis Type="Italic">a</Emphasis>]benzoxazocinones

Intramolecular [3+2]-cycloaddition was studied of munchnones generated at heating syn- and anti-atropisomers of N-acyl-N-[6-methyl-2-(cyclopent-2-en-1-yl)phenyl]glycines with acetic anhydride. By spectral and X-ray diffraction analysis syn-isomers of acids and tetrahydro-1,4,7-methanetriyl[1,3]oxazolo[3,4-a][1]- bensazocin-3(3aH)-ones were identified.     

Reaction of Imidazoles and Triazoles with 1-(Benzotriazol-1-yl)-2-iodoethanone

Reactions of 2-methyl-1H-imidazole, 1H-benzimidazole, 4H-1,2,4-triazole, and 1H-benzotriazole with 1-(1H-benzotriazol-1-yl)-2-iodoethan-1-one in the absence of a base gave the corresponding N-mono- and N,N′-disubstituted derivatives. 4H-1,2,4-Triazole-3-thiol reacted with 1-(1H-benzotriazol-1-yl)-2-iodoethan-1- one to afford 1-([1,3]thiazolo[2,3-c][1,2,4]triazol-5-yl)-1H-benzotriazolium triiodide.     

Synthesis of new functionally substituted hetarylcarbamates from methyl {4-[(2<Emphasis Type="Italic">E</Emphasis>)-3-(4-methoxyphenyl)-prop-2-enoyl]phenyl}carbamate

Three-component condensation of methyl {4-[(2E)-3-(4-methoxyphenyl)prop-2-enoyl]phenyl}- carbamate with ninhydrin and L-proline in methanol–water (10: 1) afforded methyl {4-[1,3-dioxo-1′- (4-methoxyphenyl)-1,1′,2′,3,5′,6′,7′,7a′-octahydrospiro[indene-2,3′-pyrrolizin]-2′-ylcarbonyl]phenyl}carbamate. Heating of methyl {4-[(2E)-3-(4-methoxyphenyl)prop-2-enoyl]phenyl}carbamate with isatin and benzylamine in methanol gave methyl {4-[4′-(4-methoxyphenyl)-2-oxo-5′-phenyl-1,2-dihydrospiro[indole-3,2′-pyrrolidin]-3′-ylcarbonyl]phenyl}carbamate. The condensation of methyl {4-[(2E)-3-(4-methoxyphenyl)prop-2- enoyl]phenyl}carbamate with sarcosine and 11H-indeno[1,2-b]quinoxalin-11-one generated in situ from ninhydrin and o-phenylenediamine in boiling ethanol led to the formation of methyl {4-[4′-(4-methoxyphenyl)-1′-methyl-11,11a-dihydro-5aH-spiro[benzo[b]phenazine-6,2′-pyrrolidin]-3′-ylcarbonyl]phenyl}carbamate.     

Reactions of <Emphasis Type="Italic">N</Emphasis>-(Polychloroethylidene)arene-and - trifluoromethanesulfonamides with indoles

N-(Polychloroethylidene)arene-and -trifluoromethanesulfonamides reacted with indole and N-substituted indoles to give the corresponding N-[2,2-dichloro(or 2,2,2-trichloro)-1-(1H-indol-3-yl)ethyl]-substituted sulfonamides. Unlike N-(2,2,2-trichloroethylidene)trifluoromethanesulfonamide, less electrophilic N-(poly-chloroethylidene)arenesulfonamides failed to react with 1-(4-nitrophenyl)-1H-indole. Previously unknown N,N’-bis(2,2-dichloroethylidene)biphenyl-4,4’-disulfonamide reacted with 1-benzyl-1H-indole at both azomethine fragments. Likewise, reactions of 1,6-bis(1H-indol-1-yl)hexane and 1,4-bis(1H-indol-1-ylmethyl)-benzene with N-sulfonyl trichloroacetaldehyde imines involved both indole rings in the former.     

Functionalized β-lactams based on (<Emphasis Type="Italic">E</Emphasis>)-1-(furan-2-yl)-<Emphasis Type="Italic">N</Emphasis>-[(4-methoxyphenyl)methyl]methanimine and its imine–imine rearrangement initiated by potassium hydride

Functionalized β-lactams were synthesized by reaction of (E)-1-(furan-2-yl)-N-[(4-methoxyphenyl)-methyl]methanimine with ketenes generated in situ from chloro- and dichloroacetic acids and 3-(methoxyimino) butanoic acid. (E)-1-(Furan-2-yl)-N-[(4-methoxyphenyl)methyl]methanimine underwent imine–imine rearrangement by the action of potassium hydride to give thermodynamically more stable (E)-N-[(furan-2-yl)-methyl]-1-(4-methoxyphenyl)methanimine.     

Synthesis of 3-amino-3,4-dihydroquinazolin-4-one derivatives from anthranilic acid hydrazide and dicarboxylic acids

Treatment of anthranilic acid hydrazide with 2 equiv of ethoxalyl chloride gave the corresponding diester which underwent cyclization in acetic anhydride to produce ethyl 3-(ethoxalylamino)-4-oxo-3,4-dihydroquinazoline-2-carboxylate. Acylation of anthranilic acid hydrazide first with succinic anhydride and then with ethoxalyl chloride led to the formation of 4-[2-(2-{[ethoxy(oxo)acetyl]amino}benzoyl)hydrazino]-4-oxobutanoic acid whose cyclization in acetic acid afforded N-(2-ethoxycarbonyl-4-oxo-3,4-dihydroquinazolin-3-yl)succinamic acid, while in acetic anhydride ethyl 3-(2,5-dioxopyrrolidin-1-yl)-4-oxo-3,4-dihydroquinazoline-2-carboxylate was obtained. The latter was brought into reactions with amines and hydrazine hydrate and alkaline hydrolysis. Acylation of 2-[2-(2-aminobenzoyl)hydrazinocarbonyl]benzoic acid with ethoxalyl chloride gave ethyl N-[2-(phthalimidocarbamoyl)phenyl]oxamate, and with succinic anhydride, 3-[4-oxo-3-phthalimido-3,4-dihydroquinazolin-2-yl]propionic acid. 4-[2-(2-Aminobenzoyl)hydrazino]-4-oxobutanoic acid reacted with phthalic anhydride in boiling acetic acid to give phthalazino[1,2-b]quinazoline-5,8-dione via elimination of succinic acid residue.     

New functionalization opportunities for <Emphasis Type="Italic">peri</Emphasis>-hydroxynaphthoyl and <Emphasis Type="Italic">peri</Emphasis>-fused heterocyclic compounds

A capability was studied of hydrogenated α-pyrone heterocycle in 7-methoxy-4-(4-methoxy-phenyl)-3,4-dihydro-2H-benzo[h]chromen-2-one to undergo aminolysis under the treatment with hydrazine hydrate, primary and secondary aliphatic and aromatic amines. A new approach was developed to the preparation of perihydroxyketone of naphthalene series containing a specific functional substituent in the ortho-position with respect to hydroxy group. The effect was revealed of an acetyl group in the position 9 of 7-methoxy-4-(4-methoxyphenyl)-3,4-dihydro-2H-benzo[h]chromen-2-one on the reaction of this compound with aliphatic amines and hydrazine hydrate. 9-Methoxy-1-(4-methoxyphenyl)-6-methyl-3H-benzo[de]pyrido[3,2,1-if]cinnolin-3-one [9-methyl-6-methoxy-3-(4-methoxyphenyl)-10,10a-diazapyren-1-one] was obtained, a new bis-peri-fused heteroaromatic system.     

Synthesis of 1,2,4- and 1,3,4-oxadiazoles from 1-aryl-5-methyl-1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazole-4-carbonyl chlorides

5-Substituted 2-(1-aryl-5-methyl-1H-1,2,3-triazol-4-yl)-1,3,4-oxadiazoles were synthesized by reaction of 1-aryl-5-methyl-1H-1,2,3-triazole-4-carbonyl chlorides with the corresponding 5-substituted 1H-tetrazoles. 5-Methyl-1-phenyl-1H-1,2,3-triazole-4-carbonyl chloride reacted with N′-hydroxybenzimidamides to give 3-aryl-5-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)-1,2,4-oxadiazoles. Reactions of 4-(5-methyl-1H-1,2,3-triazol-1-yl)benzoic acid with N′-hydroxybenzimidamides resulted in the formation of 3-aryl-5-[4-(5-methyl-1H-1,2,3-triazol-1-yl)phenyl]-1,2,4-oxadiazoles.     

One-Pot Assembly of Alkyl [(5-Amino-1<Emphasis Type="Italic">H</Emphasis>-pyrrol-2-yl)sulfanyl]-acetates from Propargylamines,Isothiocyanates, and Alkyl Bromoacetates

Methyl and tert-butyl 2-{[5-(diethylamino)-1-methyl-1H-pyrrol-2-yl]sulfanyl|acetates have been synthesized in one preparative stage from accessible N,N-diethylprop-2-yn-1-amine, methyl isothiocyanate, and methyl 2-bromoacetate.     

Reaction of polychloroacetaldehyde arylsulfonylimines with 2-amino-6<Emphasis Type="Italic">H</Emphasis>-1,3-thiazine-6-thiones and 2-amino-4-phenyl-6<Emphasis Type="Italic">H</Emphasis>-1,3-thiazin-6-one

2-Amino-4-R-6H-1,3-thiazine-6-thiones and 2-amino-4-phenyl-6H-1,3-thiazin-6-one react with highly electrophilic N-arylsulfonylimines of chloral and phenyldichloroacetic aldehyde at the exocyclic amino group affording in good yields products of nucleophilic addition to the azomethine group of imines: N-[2-polychloro-1-(6-thioxo-4-R-6H-1,3-thiazin-2-ylamino)ethyl]- or -[2-polychloro-1-(6-oxo-4-phenyl-6H-1,3-thiazin-2-ylamino)ethyl]arenesulfonamides.     

Some Transformations of 2-(Chloromethyl)-5,5-dimethyl-5,6-dihydrobenzo[<Emphasis Type="Italic">h</Emphasis>]quinazolin-4(3<Emphasis Type="Italic">H</Emphasis>)-one

The condensation of 1-amino-3,3-dimethyl-3,4-dihydronaphthalene-2-carbonitrile with chloroacetyl chloride afforded chloro-N-(2-cyano-3,3-dimethyl-3,4-dihydronaphthalen-1-yl)acetamide which underwent cyclization to 2-(chloromethyl)-5,5-dimethyl-5,6-dihydrobenzo[h]quinazolin-4(3H)-one. The latter reacted with various nucleophiles (alkali metal alkoxides, piperazine, 2-sulfanylethanol) to give 2-(alkoxymethyl)-, 2-(piperazin-1-ylmethyl)-, and 2-{[(2-hydroxyethyl)sulfanyl]methyl}-5,5-dimethyl-5,6-dihydrobenzo[h]quinazolin- 4(3H)-ones. The condensation of 2-(chloromethyl)benzo[h]quinazoline with 2-thioxo derivatives of quinazoline and benzo[h]quinazolines led to the formation of bis-quinazolines in which 5,5-dimethyl-5,6- dihydrobenzo[h]quinazolin-4(3H)-one fragment is linked to quinazoline or benzo[h]quinazoline system through a CH₂S bridge.     

Polyfunctional imidazoles: XIV. 4-sulfonyl-5-formyl-1<Emphasis Type="Italic">H</Emphasis>-imidazoles

Oxidative chlorination of 1-aryl-4-benzylsulfanyl-1H-imidazole-5-carbaldehydes gave 1-aryl-5-formyl-1H-imidazole-4-sulfonyl chlorides which reacted with secondary amines and phenols to produce the corresponding N,N-disubstituted 5-formylimidazole-4-sulfonamides and aryl sulfonates. The reaction of 1-aryl-5-formyl-1H-imidazole-4-sulfonyl chlorides with sodium azide, followed by reduction of the resulting sulfonyl azides, led to the formation of N-unsubstituted 5-formylimidazole-4-sulfonamides, and the reaction with alcohols, to 5-formylimidazole-4-sulfonic acids.