Halogenation of N-Substituted p-Quinonimines and p-Quinone Oxime Esters: II. Chlorination and Bromination of 4-Aroyl(arylsulfonyl)oxyimino-2-methyl-2,5-cyclohexadienones

Halogenation of 4-aroyl(arylsulfonyl)oxyimino-2-methyl-2,5-cyclohexadienones yields Z,E-isomeric 4-aroyl(arylsulfonyl)oxyimino-5,6-dihalo-2-methyl-2-cyclohexenones and (E)-4-aroyl(arylsulfonyl)oxyimino-5,6-dihalo-6-methyl-2-cyclohexenones. Further chlorination leads to formation of (Z,E)-4-aroyl(arylsulfonyl)oxyimino-2,5,6-trichloro-6-methyl-2-cyclohexenones.     

Antioxidants and stabilizers: Part XCVI—Antioxidant behaviour of 2,6-di-tert-butyl-4-(4-phenylamino-phenylimino)2,5-cyclohexadiene-1-one

In the autoxidation of squalene (rubber model) the title compound (I) first behaves as an effective antioxidant which, however, gradually loses its efficiency in the course of autoxidation without being destroyed. This behaviour is caused by a reaction in which radical (III), derived from antioxidant (I), reacts with the hydrogen atom in the oxidation products of squalene. The hydrogen atom is not that of the hydroperoxide group. In the reaction, (I) is regenerated and an active radical is formed from the substrate which continues the oxidation. Oxidation of (I) with lead dioxide gave rise to the dimer of the radical (III).     

Formation of substituted pteridines from 5,6-diaminopyrimidines and N-(arylsulfonyl)imidazolin-2-ones

Conclusions Substituted pteridinesare formed when either tetraaminopyrimidine or 4-hydroxy-2,5,6-triaminopyrimidine is reacted with N-(arylsulfonyl)imidazolin-2-ones in aqueous solution in the presence of either piperidine or triethylamine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1666–1668, July, 1981.     

Electrochemically induced transformation of 4(6)-dihalomethyl-4(6)-methylcyclohexa-2,5(2,4)-dien-1-ones into 4(2)-methyltropones

Electrochemical investigation of 4(6)-dihalomethyl-4(6)-methylcyclohexa-2,5(2,4)-dien-1-ones using cyclic voltammetry (CVA) and rotating disc electrode (RDE) methods has been performed. The reductive dehalogenation of cyclohexa-2,5(2,4)-dien-1-ones having a dihalomethyl substituent at the tertiary carbon atom was shown to proceed as a two-electron reductive elimination of the geminal halogen atoms with the intermediate formation of carbene and subsequent rearrangement of cyclohexadienone with the ring expansion to the corresponding 4- or 2-methylcyclohepta-2,4,6-trien-1-one.     

Reaction of tetraaminopyrimidine with 1-arylsulfonyl-4-methylimidazolin-2-ones

Conclusions When tetraaminopyrimidine is reacted with 1-arylsulfony1-4-methylimidazolin-2-ones, the presence of an electron-donor substituent in the aromatic ring of the arylsulfamido moiety favors the formation of 6-methy1-2,4-diaminopteridine, while an electron-acceptor substituent favors the formation of the isomeric 7-methyl-2,4-diaminopteridine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1910–1913, August, 1982.     

Reaction of 2-(2-oxo-2-arylethylidene)-2,3-dihydropyrimidine-4(1H)-ones with aldehydes

2-(2-Oxo-2-arylethylidene)-2,3-dihydropyrimidine-4(1H)-ones react with aromatic and heteroaromatic aldehydes to form the unsaturated ketones, whereas in the case of 3- and 4-benzaldehydes the corresponding trans-2-styrylpyrimidine-4(3H)-ones were obtained. A possible mechanism of hydrolytic cleavage of the product of condensation of 2-(2-oxo-2-phenylethylidene)-2,3-dihydropyrimidine-4(1H)-one with paraformaldehyde under acid catalysis and mechanochemical activation has been discussed.     

Reaction of 4-methyl-4-tribromomethylcyclohexa-2,5-dien-1-one with zinc metal

4-Methyl-4-tribromomethylcyclohexa-2,5-dien-1-one reacts with zinc dust in absolute DMF to give a mixture of 4-bromo-5-methylcyclohepta-2,4,6-trien-1-one, 4-methyl-cyclohepta-2,4,6-trien-1-one, and 4-dibromomethyl-4-methylcyclohexa-2,5-dien-1-one. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 177–178, January, 1998.     

Reaction of Substituted 2-Allylthiopyrimidin-4(3H)-ones with Sulfenyl Chlorides

Reaction of substituted 2-allylthiopyrimidin-4(3H)-ones with p-nitrobenzosulfenyl chloride gives the products of addition at the allyl moiety, while the reaction with 2-benzothiazolyl sulfenyl chloride yields thiazolidinopyrimidines with an angular structure.     

Reaction of 4-chlorohexafluoro-2,5-cyclohexadienyl fluorosulfate and hexafluoro-2,5-cyclohexadienylene 1,4-bis(fluorosulfate) with nucleophilic reagents

Conclusions In reactions with nucleophilic reagents, 4-chlorohexafluorodienyl fluorosulfate and hexafluoro-2,5-hexadienylene 1,4-bis(fluorosulfate) display a dual reactivity due to attack of the nucleophile at both the sulfur atom and the carbon atom to which the fluorosulfate groups is attached.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 375–379, February, 1987.     

Reaction of 2-substituted 1-phenyl-1,2-dihydro-4H-3,1,2-benzoxazaphosphinin-4-ones with bis(2,2,3,3-tetrafluoropropyl) 2-(4-chlorobenzylidene)malonate

Russian Journal of Organic Chemistry -     

Simple Three-Component Synthesis of 4-Acyl-1-(2-aminoethyl)-5-aryl-3-hydroxy-2,5-dihydropyrrol-2(1H)-ones

Russian Journal of General Chemistry -     

(5S)-5-烷氧基-3,4-二卤-2(5H)-呋喃酮与氨基酸的串联反应

在氢氧化钾作用下,直接以不同种类氨基酸为亲核试剂,与手性(5S)-5-烷氧基-3,4-二卤-2(5H)-呋喃酮在室温下进行串联的不对称迈克尔加成-消除反应,合成了15个新的光学活性2(5H)-呋喃酮衍生物.通过旋光度,UV-Vis,IR,1H NMR,13C NMR,MS,元素分析和X射线单晶衍射等表征方法,确定了目标化合物的化学结构和绝对构型.     

有机催化(E)-4-巯基丁-2-烯酸乙酯与4-亚胺基吡唑啉-5-酮的不对称Mannich反应

以金鸡纳碱衍生的手性双功能方酰胺为催化剂,实现了(E)-4-巯基丁-2-烯酸乙酯与4-亚胺基吡唑啉-5-酮的不对称Mannich反应,高效构建了一系列含有四取代的氨基立体中心及N,S-缩醛结构的手性吡唑啉-5-酮类化合物,收率90%,对映选择性95/5 er,其结构经¹H NMR, ¹³C NMR和HR-MS(ESI-TOF)表征。     

One-Pot Synthesis of 4-Aminoquinazolines by Hexamethyldisilazane-Mediated Reaction of Quinazolin-4(3H)-ones with Amines

Hexamethyldisilazane-mediated reaction of quinazolin-4(3H)-ones with primary amines led to facile formation of 4-aminoquinazolines through tandem silylation and substitution in a single pot. Excellent yields of the products (83–97%) and environmental friendliness (avoiding the use of chlorination reagents) are the advantages of this method.      

Reaction of arylsulfonyl compounds with excess organolithium reagent 10. Opening of the thiophene ring inβ-lithium derivatives of 2,5-bis(tert-butylsulfonyl)thiophene

Conclusions Opening of the thiophene ring is observed in the lithium derivatives of 2,5-bis(t-butylsulfonyl)thiophene, resulting in the formation of functionally substituted dienes of their transformation products.See [1] for communication 9.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1367–1370, June, 1977.     

A Simple Approach to the Synthesis of 1,4-Bis(arylsulfonyl)tetrahydropyrazine-2,5-diones

Summary.  The addition of triphenylphosphine to dimethyl acetylenedicarboxylate in the presence of arylsulfonylglycyl chlorides leads to 1,4-bis-arylsulfonyl-tetrahydropyrazine-2,5-diones and dimethyl (E)-2-chloro-2-butenedioate. Corresponding author. E-mail: isayavar@yahoo.com Received June 3, 2002; accepted June 10, 2002