Synthesis and properties of 2-substituted 1-aryl-4-oxo-1,4-dihydropyrido[2,3-d]pyrimidines

Cyclization of 2-(N-acetyl-N-arylamino)nicotinonitriles in the presence of dry HCl gave 1-aryl-2-methyl-4-oxo-1,4-dihydropyrido[2,3-d]pyrimidines. It was shown that they are acylated by acetic anhydride, aroyl chlorides, and phenyl isocyanate at the methyl group and that with benzaldehyde they give styryl derivatives. It was determined by UV, IR, and NMR spectra that 2-acetonyl, 2-phenacyl, and 2-(N-phenylcarbamoylmethyl) derivatives of 1-aryl-4-oxo-1,4-dihydropyrido[2,3-d]pyrimidines exist in enaminocarbonyl and imino enol forms with strong chelate-type intramolecular hydrogen bonding.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1397–1401, October, 1991.     

Novel Synthesis of Condensed Pyridin-2(1H)-one and Pyrimidine Derivatives

The reaction of N-chloroacetyl derivatives 6-10 with morpholine yielded N-morpholin-1-yl acetyl derivatives 11-15 , which were subjected to Thorpe-Zieler cyclization with sodium tert -butoxide to produce the corresponding condensed pyridin-2(1H)-one derivatives 16-20 . Treatment of compounds 1 , 6-10 with either malononitrile or p -chlorobenzylidinemalononitrile in presence of triethylamine, afforded the corresponding pyrimidines 21-25 , 27 and pyridine derivative 26 respectively. Moreover compound 1 a was treated with ethyl isothiocyanoacetate to give the corresponding piprazine derivative 28 .     

Enynylation of 2-iodo-4-(phenylchalcogenyl)-1-butenes via intramolecular chelation: approach to the synthesis of conjugated dienynes or trienynes

[reaction: see text] 2-Iodo-4-(phenylchalcogenyl)-1-butenes 3 and 4, which are derived from methylenecyclopropanes 1, can be enynylated with alkynes catalyzed by Pd(OAc)(2) to give conjugated dienynes 5 and 6 in the absence of any phosphine ligand and copper salt, and trienyne 9a can be obtained by oxidation of compound 5a. A plausible reaction mechanism has been proposed.     

Fluorocyclohexanes-III 1H:4H/2H- and 1H/2H:4H-nonafluorocyclohexane and derived compounds

Two nonafluorocyclohexanes of b.p. 92° and 101°, made by fluorination of benzene,¹ have each been dehydrofluorinated to give the same six unsaturated products. These were identified by oxidation and other studies as 3H:4H- and 4H:5H-octafluorocyclohexene, 1H-1:4-, 1H-1:3-, and 2H-1:3-heptafluorocyclohexadiene, and hexafluorobenzene,² thus indicating a 1H:2H:4H-structure for the saturated precursors. The stereochemistry of the adjacent> CHF groups was established by resolution, via the brucine salt, of the 3H:4H-hexafluoroadipic acid obtained by oxidation of the 4H:5H-mono-olefin, showing that the hydrogens were trans. The complete stereochemistry of the nonafluorides was suggested by the dehydrofluorinations and confirmed by further fluorination³ to give known decafluorocyclohexanes. Treatment of 4H/5H-octafluorocyclohexene with lithium aluminium hydride in diethyl ether gave 1H,4H/5H-heptafluorocyclohexene, a precursor of pentafluorobenzene.⁴     

Synthesis and Transformations of 2-Hydroxy-2-(benzotriazol-1-yl)-1,4-naphthoquinone

2-Hydroxy-3-(benzotriazol-1-yl)-1,4-naphthoquinone reacts with o-phenylenediamine and 4-chloro-2-aminophenol to give cyclization products: 5-oxo-6-(benzotriazol-1-yl)-5,6H-benzo[a]phenazine and 5-oxo-6-(benzotriazol-1-yl)-10-chlorobenzo[a]phenoxazine; the reaction with aniline yields the quaternary anilinium salt, and benzoyl chloride and benzenesulfonyl chloride acylate the nitrogen atom of the benzotriazolyl moiety.     

Ketene-S,S,-acetals—VI : Synthesis of 3,3-bis-(methylthio)-2-propene-2-alkyl-1-aryl-1-ones and their reaction with guanidine: A novel route for pyrimidine synthesis

The α-ketoketene-S,S,-acetals 2a–h have been synthesized from the appropriate ketones 1a–f in good yields by extending the established method. The acetals 2a–d react with guanidine in the presence of sodium ethoxide to give pyrimidines 4a–d in 35–59% overall yields (Scheme 1). Treatment of 2e with guanidine similarly gave 5a in 23% yield. However, the reaction of 2e with guanidine in the presence of sodium n-propoxide gave a mixture of three products from which 5a was isolated as major product (20%) with 6a (7%) and 7a (5%). Under similar reaction conditions, 2f gave 5b, 6b and 7b in identical yields. Treatment of 2g–h with guanidine in the presence of sodium n-propoxide gave only 8a (28%) and 8b (23%) respectively. The formation of these pyrimidines involves base induced 1,3-proton migration in 2a–h to give intermediate olefins 10a–h.     

Synthesis and study of 2-(1-pyrazolyl)pyrimidine derivatives

Alkyl derivatives of 2-(1-pyrazolyl)-4(3H)-pyrimidinone were synthesized and converted to 4-chloro-, 4-arylamino-, and 4-hydrazino-2-(1-pyrazolyl)pyrimidines. The corresponding hydrazones were obtained by reaction of 5-ethyl-2-hydrazino-6-methyl-2-(4-ethyl-3,5-di-n-propylpyrazolyl) pyrimidine with isatin and salicylaldehyde. The UV and IR spectra of the synthesized compounds were studied. It was established that the hydrazones contain intra-molecular hydrogen bonds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1255–1257, September, 1977.     

Synthesis and properties of 1,3-diaza-2-phospholo[4,5-d]pyrimidines

Reaction of 5-amino-4-alkyl(aryl or aralkyl)aminopyrimidines with PCl₅ gives 2,2-dichloro-3-alkyl(aryl or aralkyl)-1,3-diaza-2-phospholo[4,5-d]pyrimidines, which on treatment with piperidine or morpholine are converted into the corresponding 2,2-diamino derivatives. The latter, on boiling in water or aqueous alcohol, give the dipiperidides or dimorpholides of the corresponding 5-pyrimidylamidophosphoric acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 5, pp. 710–712, May, 1970.     

A novel approach to substituted 2H-azirines

2-(Benzotriazol-1-yl)-2H-azirines 4a-c, obtained by treatment of oximes 2a-c with tosyl chloride and aqueous KOH, were reacted with benzylmagnesium bromide or 4-methylbenzylmagnesium bromide in the presence of zinc chloride to give 2-benzyl-2H-azirines 5a-f. Potassium phthalimide and sodium salt of benzenethiol converted 2-(benzotriazol-1-yl)-2H-azirines 4a-c into novel 2H-azirines 6a-c and 7 in good yields.     

Synthesis of 6-Amino-5-R2-7-(6-R1-4-oxo-3,4-dihydro-2-quinazolyl)-5H-pyrrolo[2,3-b]pyrazine-2,3-dicarbonitriles

It has been found that malonodinitrile and 2-(6-R¹-oxo-3,4-dihydro-2-quinazolyl)acetonitrile in the presence of triethylamine undergo hetarylation by 5,6-dichloro-2,3-pyrazinedicarbonitrile at the active methylene group to give the triethylammonium salt of 2-(3-chloro-5,6-dicyano-2-pyrazinyl)malononitrile or 5-chloro-6-cyano(6-R¹-4-oxo-1,2,3,4-tetrahydro-2-quinazolylidene)methyl-2,3-pyrazinedicarbonitriles. Reaction of these with primary amines leads to annelation of the pyrrole ring at the pyrazine [b] edge to give 6-amino-5-R-5H-pyrrolo[2,3-b]pyrazine-2,3,7-tricarbonitriles and 6-amino-5-R²-7-(6-R¹-4-oxo-3,4-dihydro-2-quinazolyl)-5H-pyrrolo[2,3-b]pyrazine-2,3-dicarbonitriles respectively.     

Synthesis and antimalarial effects of 2-(3,4-dichloroanilino)-7-[[[(dialkylamino)alkyl]amino]]-5-methyl-s-triazolo[1,5-a]pyrimidines

3,4-Dichlorophenylisothioeyanate ( 10 ) was allowed to react with 2-methy1-2-thiopseudourea to give methyl 4-(3,4-dichlorophenyl)(dithioaltophanimidate ( 11 ) (41%), which upon treatment with hydrazine afforded 3-amino-5-(3,4-dichloroanilino)-s-triazole ( 12 ) (54-91%). Ring-closure with ethyl acetoacetale in acetic acid afforded 2-(3,4-dichloroanilino)-5-methyl-s-triazolo[ 1,5-α ]-pyrimidin-7-ol ( 13 ) (81%). Chlorination with phosphorus oxychloride gave 7-chloro-2-(3,4-dichloroanilino)-5-methyl-s-triazolo[1,5-α ]pyrimidine ( 14 ) (98%), which was condensed with various amines to yield the desired 2-(3,4-diehloroanilino)-7-¶[(dialkylamino)alkyl]arnino¶-5-methyl-s-triazolo[ 1,5-α]pyrimidines ( 6 a-d). The structures of the s-triazolo[ 1,5-α ]pyrimidines were based on nmr spectroscopy and ring stability considerations. Several of the amino-s-triazolo[ 1,5-α ]pyrimidines possessed antimalarial activity against P. berghei in mice.     

Pyrimidines. 24. Analogues and derivatives of 2-amino-5-bromo-6-phenyl-4(3H)-pyrimidinone (ABPP)

Preparation of a number of derivatives of 2-amino-5-bromo-6-phenyl-4(3H)-pyrimidinone (ABPP) including the 2-dialkylaminoalkylamino-, 2-hydroxyalkylamino-, 2-ethoxycarbonylamino- and 2-alkylaminocarbonyl-amino- groups substituted on the pyrimidine ring as well as preparation of 1-(alkylaminoalkyl)-4,6-dioxo-8-phenyl-2,3,4,6-tetrahydro-1H-pyrimido[1,2-α]pyrimidines and 3,5-dioxo-7-phenyl-1,2,3,5-tetrahydroimidazo-[1,2-α]pyrimidines with or without the bromo-substitution are reported.     

Synthesis of 2- and 4-imino(1,2-a)pyridopyrimidines from allenic nitriles and 2-aminopyridines

4,4-Dialkylallenyl nitriles and 2-aminopyridines give 2-alkyl-4-iminopyrido(1,2-a)pyrimidines as monohydrates in about 90% yield and 4-monoalkylallenyl nitriles similarly give 4-alkyl-2-imino(1,2-a)pyrimidines.     

Thermische Reaktionen mit 3-Phenyl-2H-azirinen; 1, 3-dipolare Cycloadditionen und En-Reaktionen

Benzonitrile p-nitrobenzylide ( 5 ) undergoes 1,3-dipolar cyclo-additions in the presence of 3-phenyl-2H-azirines ( 1 ), yielding in benzene at 0° 2-(p-nitrophenyl)-4,5-diphenyl-1,3-diazabicyclo[3.1.0]hex-3-enes ( 7 , scheme 2). Under the basic conditions of the reaction mixture, 7 a and 7 b are partially converted to 2-(p-nitrophenyl)-4,5-diphenyl-1,6-dihydropyrimidines ( 8a, b ) which are dehydrogenated by oxygen to the corresponding pyrimidines 9a and 9b , respectively. 3-Phenyl-2H-azirines ( 1 ) form, on heating at 145° in xylene in the presence of the azalactone 32 (2,4-diphenyl-Δ²-oxazolin-5-one), 4-(aziridin-2′-yl)-2,4-diphenyl-Δ²-oxazolin-5-ones ( 33 , scheme 11). 33 arises from an ene reaction of the enol form of 32 with 1 . Similar ene reactions are observed with the azirines 1 and dimedone ( 37 , scheme 12). Under the ene reaction conditions (xylene, 145°), the non-isolated intermediate primary adducts ( 38a and 38b ) undergo rearrangements of the vinylcyclopane-cyclopentene type to give 6,6-dimethyl-4-oxo-1,3-diphenyl-4, 5, 6, 7-tetrahydroisoindole ( 40 ) and 6, 6-dimethyl-4-oxo-3-phenyl-4, 5, 6, 7-tetrahedroindole ( 42 ), respectively.     

Tetrazole compounds. 8. Synthesis of tetrazolylpyrimidines from tetrazolyl-substituted enamino ketones

Tetrazolyl-substituted enamino ketones 1 react with various amidines 2 to give 5-(1-phenyl-1H-tetrazol-5-yl)pyrimidines 3 . In the case of the chloroacetyl enamine 4 4-(N,N-dimethylaminomethyl)-substituted tetra-zolylpyrimidines 5 were obtained. Subsequent hydrolysis of the 4-trifluoromethyl derivatives 3b, 3d and 3g afforded the corresponding 5-(1-phenyl-1H-tetrazol-5-yl)pyrimidine-4-carboxylic acids 6 .     

Syntheses and properties of new herbicidal 2-arylthio-1 ,2,4-triazolo[1,5-a] pyrimidine derivatives

In search of novel herbicides with high activity, a series of 2-arylthio-1,2,4- triazolo [1, 5-a ] pyrimidines (3) were synthesized by cyclization of 5-amino-3-arylthio-1,2,4-triazoles with 1,3-diketones or by the nucleophilic substitution of substituted thiophenols with 2-methylsulfonyl-1, 2, 4-triazolo [ 1, 5-a]-pyrimidine. The structures of all compounds prepared were confirmed by 1H NMR and MS spectroscopy along with elemental analyses. Preliminary bioassays indicated that some of the compounds 3 had good herbicidal activity against rape. In addition, the regioselectivity in the reaction of 5-amino-3-sub-stituted arylthio-1,2,4-triazoles with benzoylacetone was studied.     

Synthesis of 2,4,6-trisubstituted 5-(2-alkylsulfanylethyl)-pyrimidines and some their transformations

New 2,4,6-trisubstituted 5-(2-alkylsulfanylethyl)pyrimidines were synthesized by condensation of ethyl 2-(2-alkylsulfanylethyl)-3-oxobutanoates with various amidines and thiourea. Fusion of substituted 2,6-dimethylpyrimidin-4(3H)-ones with aromatic aldehydes gave the corresponding 6-styrylpyrimidines. Some 5-(2-alkylsulfanylethyl)pyrimidines were oxidized to sulfoxides, and amination of 5-[2-(butylsulfanyl)ethyl]-6-methyl-2-propylsulfanylpyrimidin-4(3H)-one with 4-aminobenzoic acid afforded 4-{5-[2-(butylsulfanyl)ethyl]-4-methyl-6-oxo-1,6-dihydropyrimidin-2-ylamino}benzoic acid.     

Heterocyclization of 2-chloro-1-cyano-1-diethoxyphosphoryl-2-trifluoromethylethylene and 2-chloro-2-chlorodifluoromethyl-1-cyano-1-diethoxyphosphorylethylene

The reactions of 2-chloro-1-cyano-1-diethoxyphosphoryl-2-trifluoromethylethylene (2a) and 2-chloro-2-chlorodifluoromethyl-1-cyano-1-diethoxyphosphorylethylene (2b) with arylamines, arylhydrazines, amidines, 2-aminopyridines, and 5-aminopyrazoles were studied. Alkenes 2a, b can serve as precursors of aminopyrazoles, pyrimidines, pyrido[1,2-a]pyrimidines, and pyrazolo[1,5-a]pyrimidines modified with the fluoroalkyl and diethoxyphosphoryl groups. Intermediates of some heterocyclization reactions were detected by NMR spectroscopy. The structures of the compounds were confirmed by X ray diffraction analysis.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1977–1986, September, 2004.     

1-(2'-苯基-1', 2', 3'-三唑-4'-甲酰基)-4-芳基氨基硫脲及其 环化产物的合 成

以2-苯基-1,2,3-三唑-4-甲酰肼为原料合成了几种新的1-(2'-苯基-1',2',3'-三唑-4'-甲酰基)-4-芳基氨基硫脲,在不同条件下环化,制得一系列新的1,3,4-噻二唑、1,3,4-恶二唑和1,2,4-均三唑衍生物。化合物的结构经元素分析、IR、^1HNMR和MS确证,并对其波谱性质进行了讨论。     

Anil-Synthese. 23. Mitteilung. Über die Herstellung von Styryl- und Stilbenyl-Derivaten des Pyrimidins

Preparation of Styryl and Stilbenyl Derivatives of Pyrimidines 2- and 4-(p-Tolyl)-substituted pyrimidines react with anils of hetero-aromatic aldehydes in the presence of dimethylformamide and potassium hydroxide or potassium t-butoxide to yield the corresponding 2- and 4-[4″-(heteroaryl)stilben-4′-yl]pyrimidines or the 2- and 4-[a-(heteroaryl)-4′-styryl]pyrimidines respectively (‘Anil synthesis’). Furthermore, the Schiff′s bases derived from p-chloroaniline and 4-(pyrimidine-2-yl and 4-yl)benzaldehydes give, with methyl- and with p-tolyl-substituted heterocycles, the corresponding heterocyclic substituted styryl and stilbenyl derivatives. Alkyl-, alkoxy- or phenyl-substituted pyrimidines undergo also the ‘Anil synthesis’.