A general method for the solid-phase synthesis of unsymmetrical tri- and tetrasubstituted ureas

A general method for the preparation of unsymmetrical di, tri-, and tetrasubstituted ureas on polymer supports is presented. Polymer-bound primary and secondary amines react with imidazolium salts (urea donors), which are generated from the reaction of N,N'-carbonyldiimidazole (CDI) with primary and secondary amines followed by alkylation with MeI to give tri- and tetrasubstituted ureas in excellent yields (76-98%) and purities (80-99%).     

Sels de pyrylium—XVII: Réactivité des sels de dialcoxy-2,4 pyrylium avec des agents nucléophiles. Formation et propriétés de sels d'amino-2 et de diamino-2,4 pyrylium; sels de dialcoxy-2,4 pyrylium,agents d'alcoylation

Secondary amines react with 2,4-dialcoxy 6-méthyl pyrylium salts to give two new series of 2-amino and 2,4-diamino pyrylium cations. 2,4-Dialkoxy pyrylium salts react as alkylating reagents. A comparison with 1,3-dialcoxy carbonium cations reactivity is reported.     

The reactions of some pyraiiylideneiminium salts with amines. II

The iminium salt, N,N-dimethyl-N-[2-(2-phenyl-4H-l-benzopyran-4-ylidene)ethylidene] imin-ium perchlorate ( 3 ), reacts with secondary amines by exchanging the dimethylimino group for the added amine. Primary amines also reacted with 3 in the same manner. The bis iminium salts, N,N,N',N'-tetramethyl-N,N'-[2-(2-phenyl-4H-l-benzopyran-4-ylidene)-1,3-propanediylidene]-bis(immium perclilorate) ( 4 ) and the corresponding thiapyran derivative ( 5 ), react with ammonia to give 5-dimethylamino-2-phenyl-5H-1-benzopyrano[3,4-c]pyridine ( 10 ) and the thia analog 11 . The reactions of 4 and 5 with primary amines give 3-alkyl-5-dimethylamino-2-phenyl-5H-l-beiizopyrano[3,4-c]pyridinium perclilorate salts or the corresponding thiapyrano compounds. Compounds 4 and 5 react with secondary amines by exchanging the dimethylimino groups with the secondary amine and addition of the amine at the 2-position of the pyran or thiapyran ring.     

N- and O-arylation with triphenylantimony ortho-phenylenedioxides

2,2,2-Triphenyl-1,3,2-benzodioxastibolanes react with alcohols, phenols, and amines in the presence of copper salts to give the corresponding O- and N-phenyl derivatives. Cyclic Sb^V dialkoxide containing an electron-withdrawing nitro group in the dioxastibolane fragment is most reactive in N-phenylation of primary and secondary amines. Organoantimony analogs containing electron-donating groups are more efficient in O-phenylation of primary and secondary alcohols and phenols.     

Coupling of two diazotized 3‐aminothieno[3,4‐c]coumarins with aromatic amines

The coupling reactions of two diazotized 3‐aminothieno[3,4‐c]coumarins were investigated. Compounds 1a , 1b both react with sodium nitrite in concentrated sulphuric acid at 0–5°C to give the diazotized intermediates 2 and 3 , the latter resulting from the acid ‐catalyzed hydrolysis of the lactonic ring of 2 . The in situ formed diazonium salts react with aromatic amines ( 4 ) to afford a series of arylazothiophenes dyes in the form of their ammonium sulfate salts. With diazotized aniline, besides the normally expected phenylazothiophene 10 from the reaction with compound 1a , the corresponding product of acid hydrolysis 11 was also isolated. In at least one of the cases, the thienyl diazonium salt 2 undergoes a Gomberg–Bachmann arylation reaction with p‐nitroaniline to give the 2‐arylthiophene 9 . The direct hydrolysis of compounds 1a , 1b by concentrated sulphuric acid and subsequent oxidative dimerization of the primary product of acid hydrolysis led to compound 12 . J. Heterocyclic Chem., (2011).     

Reaktionen der Perthiophosphonsäureanhydride mit Aminen und Ammoniak

Perthiophosphonic anhydrides react with amines to give the corresponding ammonium salts of amido dithiophosphonic acids, while ammonia reacts to give ammonium trithiophosphonates and thiophosphonic diamides. The chemical shifts δ_P of numerous thiophosphonic derivatives are listed.     

Aminopentadiene imines from zincke salts of 3-alkylpyridines. Application to a synthesis of pyridinium salts from amino acids

The reaction of Zincke salts with primary amines to give pyridinium salts generally requires rather elevated temperature to go to completion (50-100 degrees C). It is shown that the addition of 1 equiv of a secondary amine allows formation, at ambient temperature, of intermediate aminopentadiene imine salts which can be isolated and were found to cyclize in acidic medium to give pyridinium salts at temperatures which do not exceed 50 degrees C. If this process has a tendency to give lower yields of pyridinium salt than the standard Zincke procedure, it can be advantageous in some cases, as illustrated by the synthesis of pyridinium salts from amino acids, a challenging reaction which does not work starting from Zincke salt in the absence of diethylamine. More generally, the reaction can be extended to primary amines featuring polar functions, as exemplified by a pyridinium salt synthesis (75 degrees C) in 55% yield from l-carnosine.     

Reaction of arylthiacyclanylsulfonium salts with nitrogen bases

When arylthiacyclanylsulfonium salts are heated with nitrogen bases the C-S bond of the heteroring undergoes quantitative cleavage and the base adds to form a C-N bond. These sulfonium salts react with ammonia or pyridine to give ammonioalkyl sulfides; amino sulfides and secondary amine salts are obtained with excess secondary amines. The described reaction is a new preparative method for the synthesis of amino sulfides and ammonioalkyl aryl sulfides.     

Three ways of reactions of 5-(3,5-dimethyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-1-yl)-2-phenyl-1,3-oxazole-4-carbonitrile and its analogs with nitrogen-containing bases

Substituted 5-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3-oxazole-4-carbonitrile differently react with nitrogen bases having different numbers of labile hydrogen atoms. Treatment of the title compounds with secondary amines or morpholine results in nucleophilic replacement of the pyrazolyl substituent at C⁵, the ozaxole ring remaining unchanged. Their reactions with primary amines are accompanied by cleavage of the oxazole ring with formation of the corresponding enamino nitriles. Hydrazine hydrate acts in a similar way, but enehydrazino nitriles thus formed undergo fast cyclization to give new 4,5-diaminopyrazole derivatives. The latter can be converted into substituted pyrazolo[1,5-a]pyrimidines whose structure has been proved by X-ray analysis.     

Benzotriazole-1-carboxamidinium Tosylate: An Alternative Method for the Conversion of Amines to Guanidines

A novel, effective and convenient reagent for the conversion of amines to guanidines is presented. Various primary and secondary amines react with benzotriazole-1-carboxamidinium tosylate (1) to give the corresponding guanidines in good yields under mild conditions.     

Synthesis of some N-triazinebenzoxazolinones and s-triazine-benzoxazolylsulfides

Tris(benzoxazolinonyl)triazines are obtained from cyanuric chloride and benzoxazolinone. Mercaptobenzoxazoles are converted to tris (benzoxazolylsulfido)triazines. The sodium salts of benzoxazolinone and mercaptobenzoxazole react with cyanuric chloride to give respectively mono(benzoxazolinyl)dichlorotriazines and mono(benzoxazolylsulfido)dichlorotriazines. The latter react with aliphatic amines to give benzoxazolonyldiamidotriazines or benzoxazolonylamidochlorotriazines, depending on the ratios of the reactants. Monobenzoxazolonyldichlorotriazines are fungicides for Botritis cinerea.     

Synthesis of cyclic oxoenaminoesters

Ammonia and primary amines react with dimethyl 3-oxo-1,ω-alkanedioates to give cyclic,N-acylated enaminoesters.     

1.5-Diaza-3.7-diphospha-cyclooctane

The alkyl (aryl)-bishydroxymethylphosphines react with primary amines to give the title compounds. With optically active amines optically active phosphines are formed.     

Reaction with Aqueous Alkali of Diammonium Salts with a 1,1-Dimethylbut-2-yne-1,4-diyl Common Group

Quaternary ammonium salts with a 1,1-dimethylbut-2-yne-1,4-diyl common group react with aqueous alkali with intermediate formation of 1,2- rather than 1,4-cleavage products. When both nitrogen atoms bear allylic groups, rearrangement-cleavage-substitution occurs to give methyl isopropyl ketones. Salts with two 3-methylbut-2-en-1-yl groups cleave isoprene.     

Reaction of metallo S-alkyl N-cyanodithioiminocarbonates and alkyl N-cyanocarbamates with hydrazine. A novel preparation of 5-amino-3-mercapto-1,2,4-triazole

Metal salts of S-alkyl-N-cyanodithioiminocarbonates 7 react as electrophiles with hydrazine hydrate to form 5-amino-3-mercapto-1H-1,2,4-triazole 1 . The novel 4-cyanothiosemicarbazide 9 is proposed as the intermediate which cyclizes to the aromatic triazole. The rate determining step is addition of hydrazine to the iminocarbonate and is second order. Other nucleophiles such as substituted hydrazines and amines failed to react. Exchange of either or both sulfurs with oxygen leads to decomposition or mixtures of products.     

2-Benzopyrylium salts

The properties of 1,3-dimethyl-6,7-dialkoxy-2-benzopyrylium salts were studied. The heterocyclic oxygen atom is readily replaced by nitrogen by reaction of the 2-benzopyrylium salts with primary amines, hydrazine, phenylhydrazine, glycine ethyl ester, and hydroxylamine; reaction with secondary amines leads to naphthalene derivatives. The activities of the methyl groups in the 1 and 3 positions of the heterocyclic ring are compared.For Communication IX, see [6].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1308–1312, October, 1970.     

The solid-phase Zincke reaction: preparation of omega-hydroxy pyridinium salts in the search for CFTR activation

A study of structural modifications of MPB-07 was undertaken as part of a synthetic program aimed at discovering small molecules with CFTR activation potential. Solid-phase synthesis techniques were used to prepare derivatives of MPB-07 employing the Zincke reaction for the construction of aromatic, quaternary ammonium salts such as those found in 2 or 3. In this transformation, primary amines react with highly electrophilic N-2,4-dinitrophenylpyridinium (DNP) salt 4 to afford pyridinium salt 8 with release of 2,4-dinitroaniline 6. Thus, the reaction of 1-(2,4-dinitrophenyl)pyridinium salts with various polymer-bound amino ethers, followed by cleavage from the resin, delivers the desired salts in good yield and high purity.     

Recyclization of indolo[2,3-c]pyrylium salts by reaction with secondary amines

1-R-3-methylindolo[2,3-c]pyrylium salts react with cyclic secondary amines (morpholine, piperidine, and N-methylpiperazine) to give, depending on the structure of the alkyl substituent R, either 1- (when R=Me) or 3-aminocarbazoles (when R=i-Pr), or mixtures of both (when R=Et). The position of the amino-substituent in 1-morpholino-3,9-dimethylcarbazole has been established by x-ray diffraction examination.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 546–551, April, 1990.     

Some nucleophilic substitution reactions of 2-chloro-3-cyanopyridines

The chlorine atom in 2-chloro-3-cyanopyridines is readily replaced by primary and secondary aliphatic amines and heterocyclic amines to give 2-aminopyridines. 2-Chloro-3-cyanopyridines react with hydrazine hydrate and sodium azide to give hydrazinopyridines, pyridopyrazoles, azidopyridines, and pyridotetrazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1085–1088, August, 1976.     

The reaction of isocyanide—mercuric chloride complexes with amines. Preparation of guanidines

Isocyanide—mercuric chloride complexes react readily with an excess of primary and secondary amines to give guanidines and metallic mercury in high yields through a redox decomposition reaction. In the presence of triethylamine, isocyanide—mercuric chloride complexes react with an equimolar amount of a primary amine to give a carbodiimide and metallic mercury. An intermediate organomercuric compound was isolated in the reaction of the isocyanide—mercuric chloride complex with pyrrolidone.