Reaction of indoles with ethyl bromopropynoate over Al<Subscript>2</Subscript>O<Subscript>3</Subscript> surface

1H-Indole and 2-methyl-1H-indole reacted with ethyl 3-bromopropynoate over aluminum oxide to give mixtures of the corresponding ethyl 3-(1H-indol-3-yl)propynoates and ethyl 3,3-bis(1H-indol-3-yl)-acrylates, the latter prevailing.     

A New Approach to the Synthesis of Functional Derivatives of 3-(4-Pyridinyl)-1<Emphasis Type="Italic">H</Emphasis>-indole and 4-(1<Emphasis Type="Italic">H</Emphasis>-Indol-3-yl)thieno[2,3-<Emphasis Type="Italic">b</Emphasis>]pyridine

Sequential reaction of indole-3-carbaldehyde with cyanothioacetamide and KOH led to the formation of potassium 6-amino-4-(1H-indol-3-yl)-3,5-dicyanopyridine-2-thiolate. S-Alkylation of the latter afforded new functional derivatives of 3-(pyridine-4-yl)-1H-indole and 4-(1H-indol-3-yl)-thieno[2,3-b]pyridine.     

Synthesis of new imidazo[2,1-<Emphasis Type="Italic">b</Emphasis>][1,3]thiazole derivatives from 2-amino-4-(2,2-dichlorovinyl)-1,3-thiazole and <Emphasis Type="Italic">N</Emphasis>-(2,2-dichloro-2-phenylethylidene)arenesulfonamides

2-Amino-4-(2,2-dichlorovinyl)-1,3-thiazole reacted with highly electrophilic N-(2,2-dichloro-2-phenylethylidene)- and N-(2,2,2-trichloroethylidene)arenesulfonamides through the exocyclic amino group to give products of nucleophilic addition to the azomethine bond, N-[2,2-di(or 2,2,2-tri)chloro-1-(1,3-thiazol-2-ylamino)ethyl]arenesulfonamides in good yields. Intramolecular heterocyclization of the latter afforded N-[3-(2,2-dichloroethyl)-6-phenylimidazo[2,1-b][1,3]thiazol-5-yl]arenesulfonamides.     

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.     

Reactions of <Emphasis Type="Italic">N</Emphasis>-(2,2,2-trichloroethylidene)- and <Emphasis Type="Italic">N</Emphasis>-(2,2-dichloro-2-phenylethylidene)arenesulfonamides with biuret

N-(2,2,2-Trichloroethylidene)- and N-(2,2-dichloro-2-phenylethylidene)arenesulfonamides react with an equimolar amount of biuret to give 1-(1-arylsulfonylamino-2,2,2-trichloroethyl)- or 1-(1-arylsulfonylamino-2,2-dichloro-2-phenylethyl)biurets. The reactions with 2 equiv of N-(polychloroethylidene)arenesulfonamides involve both amino groups in the biuret molecule, yielding the corresponding 1,5-bis(1-arylsulfonylamino-2,2,2-trichloroethyl)- and 1,5-bis(1-arylsulfonylamino-2,2-dichloro-2-phenylethyl)biurets.     

Reaction of 2-(2-oxo-2,3-dihydro-1<Emphasis Type="Italic">H</Emphasis>-indol-3-ylidene)acetic acid esters with benzene-1,2-diamine and 2-aminobenzenethiol

2-(2-Oxo-2,3-dihydro-1H-indol-3-ylidene)acetic acid esters reacted with benzene-1,2-diamine or 2-aminobenzenethiol to give (2-oxo-2,3-dihydro-1H-indol-3-yl)-substituted 3,4-dihydroquinoxalin-2(1H)-ones or 2H-1,4-benzothiazin-3(4H)-ones.     

Synthesis of fluoroquinoxalin-2(1<Emphasis Type="Italic">H</Emphasis>)-one derivatives containing substituents in the pyrazine and benzene fragments

6,7-Difluoroquinoxalin-2-one reacted with indoles, 5,5-dimethylcyclohexane-1,3-dione, 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one, resorcinol, and pyrogallol on heating in acetic acid to give products of hydrogen substitution in the heterocyclic fragment. Heating of 6,7-difluoro-3-(1H-indol-3-yl)quinoxalin-2(1H)-ones with N-methylpiperazine gave the corresponding 7-(4-methylpiperazin-1-yl) derivatives.     

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.     

Acylation of Fischer’s Base with Methyl Aroylpyruvates

Methyl (Z)-4-aryl-2-hydroxy-4-oxobut-2-enoates (methyl aroylpyruvates) reacted with 1,3,3-trimethyl- 2-methylidene-2,3-dihydro-1H-indole (Fischer’s base) to give (2Z,5E)-1-aryl-3-hydroxy-5-(1,3,3-trimethyl-2,3-dihydro-1H-indol-2-ylidene)pent-2-ene-1,4-diones.     

Synthesis of 2-Mono- and 2,2-Bis[2-(1<Emphasis Type="Italic">H</Emphasis>-tetrazol-5-yl)ethyl] Derivatives of Dipterocarpol

The azidation of 2,2-bis(2-cyanoethyl)-20-hydroxydammar-24-en-3-one afforded new tetrazole derivatives of natural dipterocarpol, 2-(2-cyanoethyl)-2-[2-(1H-tetrazol-5-yl)ethyl]-20-hydroxydammar-24-en- 3-ones, 2,2-bis[2-(1H-tetrazol-5-yl)ethyl]-20-hydroxydammar-24-en-3-one, and 2,2-bis[2-(1H-tetrazol-5-yl)- ethyl]-3-oxo-25,26,27-trinordammaran-(20S),24-olide. The structure of the final and intermediate products was determined by NMR spectroscopy and X-ray analysis.     

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.     

Reaction of 2-(2-Oxo-1,2-dihydro-3<Emphasis Type="Italic">H</Emphasis>-indol-3-ylidene)acetic acids esters with phenylhydrazine

2-(2-Oxo-1,2-dihydro-3H-indol-3-ylidene)acetic acids esters reacted with phenylhydrazine yielding products of the regioselective addition of the latter in the α-(C²)-position of the exo ethylene bond, (2-oxo-2,3-dihydro-1H-indol-3-yl)(2-phenylhydrazino)acetic acids esters.     

New approach to the preparation of <Emphasis Type="Italic">p</Emphasis>-(1-cyanoethyl)arenesulfonamides by reaction of arylsulfonyl imines of polychloroacetaldehydes with acetone cyanohydrin

Reaction of N-(2,2,2-trichloroethylidene)- or N-(1-phenyl-2,2-dichloroethylidene)arenesulfonamides with acetone cyanohydrin in acetone in the presence of potassium carbonate led to the formation of N- (2,2,2-trichloro-1-cyanoethyl)- or N-(2-phenyl-2,2-dichloro-1-cyanoethyl)arenesulfonamides.     

<Emphasis Type="Italic">N</Emphasis>-(4-methoxy-3-nitrobenzyl) derivatives of some nitrogen-containing heterocycles

A number of nitrogen heterocycles reacted with 4-methoxy-3-nitrobenzyl chloride in dimethyl-formamide in the presence of potassium carbonate to give the corresponding N-(4-methoxy-3-nitrobenzyl) derivatives. The reaction of 5-fluoro-1,3-bis(4-methoxy-3-nitrobenzyl)pyrimidine-2,4(1H,3H)-dione with aqueous methylamine afforded N,N′-bis(4-methylamino-3-nitrobenzyl)urea, whereas analogous reaction with 1-(4-methoxy-3-nitrobenzyl)-2-(methylsulfanyl)-1H-benzimidazole resulted in substitution of the methoxy group by methylamino.     

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 2-(3,4,5-trimethoxybenzoyl)-4(5)-phenyl-1<Emphasis Type="Italic">H</Emphasis>-imidazole

The condensation of (2E)-N-hydroxy-2-hydroxyimino-2-phenylethanamine with 3,4,5-trimethoxyphenylglyoxal afforded (1-hydroxy-5-phenyl-1H-imidazol-2-yl)phenylmethanone which reacted with trimethyl phosphite or chloroacetone to give 2-(3,4,5-trimethoxybenzoyl)-4(5)-phenyl-1H-imidazole.     

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 of 2-(halomethyl)-3,4-dihydro-2<Emphasis Type="Italic">H</Emphasis>-pyrido[2,1-<Emphasis Type="Italic">b</Emphasis>][1,3]oxazinium halides

Alkylation of pyridin-2(1H)-one and 5-nitropyridin-2(1H)-one with 4-bromobut-1-ene afforded a mixture of N- and O-butenyl derivatives. 1-(But-3-en-1yl)pyridin-2(1H)-one and 1-(but-3-en-1-yl)-5-nitropyridin- 2(1H)-one reacted with bromine and iodine to give 2-(halomethyl)-3,4-dihydro-2H-pyrido[2,1-b][1,3]-oxazinium halides.     

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.     

Reaction of <Emphasis Type="Italic">N</Emphasis>-(carbamimidoyl)thiourea with 1-benzoyl-2-phenylacetylene

1-Benzoyl-2-phenylacetylene reacted with N-(carbamimidoyl)thiourea in glacial acetic acid saturated with 20% HBr to give (4,6-diphenyl-2H-1,3-thazin-2-ylidene)guanidine hydrobromide. The reaction of the same compounds in anhydrous ethanol in the presence of sodium ethoxide led to the formation of N-(4,6-diphenylpyrimidin-2-yl)thiourea. Bis(3-oxo-1,3-diphenylprop-1-en-1-yl) sulfide and 1-benzoyl-2-ethylsulfanyl-2-phenylethylene were isolated in the reactions of 1-benzoyl-2-phenylacetylene with N-(carbamimidoyl)thiourea and N-(carbamimidoyl)-S-ethylisothiuronium bromide, respectively, in anhydrous methanol.