- The addition of SF5Br to acrylic esters: Pathways to γ-SF5-propane derivatives
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Reaction of SF5Br with various acrylic esters, CH2CHCOOR, where R=C2H5/C(CH3)3 and CH2C(CH3)COOCH3, CH2C(CH2Cl)-COOC2H5, CH2C(n-C7H15)COOC2H5 resulted in 1:1 adducts with the SF5-group attached to the CH2 portion of the acrylic ester. These adducts were converted to halogen-free saturated esters, an alcohol [SF5(CH2)3OH] an acid [SF5(CH2)2COOH] and a bromide [SF5(CH2)3Br]. Therefore, a method for chain-elongation of SF5-aliphatic hydrocarbons has been devised. With ethyl acrylate, a 2:1 adduct was also isolated. The reaction of SF5Cl with (C2H5O)2CCHCOOC2H5 gave chloromalonate. The compounds were characterized by their infrared, nuclear magnetic and mass spectral data.
- Winter,Gard
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Read Online
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The preparation of magnesium, zinc or lithium malonic or acetoacetic type enolates through halogen-metal interconversion or direct reaction of a metal on the appropriate halogenated compound is reported. The properties of these new reagents (electrophilicity, nucleophilicity and stability) are compared to those of gem-halogenated organometallics and unchelated enolates.
- Villieras, Jean
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Read Online
- Synthetic routes for a variety of halogenated (chiral) acetic acids from diethyl malonate
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Chiral halomethane is the smallest stable molecule with a single asymmetric C-atom and halogenated acetic acids often serve as precursors. We focus on a synthetic route to synthesise chiral halogenated acetic acids with F, Cl, Br, and H/D isotopic substitution at the α-C-atom starting from diethyl malonate. This reactant is easily available, cheap and allows the obtainment of target acids in a few reaction steps with great versatility. Among all of the possible fully halogenated acetic acids (more than one hundred, which are, in principle, accessible by this route), there are only a small number of chiral halogenated acetic acids, which have been synthesized following the devised synthetic route.
- Mazenauer, Manuel R.,Manov, Stole,Galati, Vanessa M.,Kappeler, Philipp,Stohner, Jürgen
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Read Online
- Preparation and refining method of high-purity diethyl malonate
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The invention relates to a preparation and refining method of high-purity diethyl malonate, and belongs to the technical field of chemical preparation. The preparation method can obtain high-purity chloropropionic acid diethyl ester by taking diethyl malonate as the starting material, carrying out the reaction with sodium sulfite instead of reacting with sodium sulfite, and carrying out rectification and purification. Compared with the prior art, the method has the advantages of cheap and easily available raw materials and reduced production cost. The purity of the product after rectification purification is up to 99%. The reaction time is short, and the production cycle is shortened. No complicated post-treatment operation is needed in the reaction, and the operation is simple. The compound I rectified by the reaction can be recycled, and the atom economy of the reaction is good. The reaction does not generate a large amount of waste liquid and is more environment-friendly.
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Paragraph 0062-0064
(2021/10/16)
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- Synthesis method of 4,5,6-trichloropyrimidine
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The invention particularly relates to a synthesis method of 4,5,6-trichloropyrimidine. The method comprises the following steps: 1, dissolving diethyl malonate in dichloromethane, adding chlorosuccinimide at room temperature, and reacting to obtain an intermediate diethyl 2-chloromalonate; 2, dissolving sodium methoxide in methanol, cooling to room temperature, adding formamidine hydrochloride, stirring at room temperature after addition, adding the diethyl 2-chloromalonate in a dropwise manner, heating, carrying out a reflux reaction for 2-3 hours after addition, and purifying to obtain an intermediate 5-chloro-4,6-dihydroxypyrimidine; and 3, mixing the intermediate 5-chloro-4,6-dihydroxypyrimidine, phosphorus oxychloride and an organic alkali according to a weight ratio of 1:(5-10):(0.3-2), carrying out a chlorination reaction at 25-100 DEG C for 2-5 hours, cooling the mixture, carrying out reduced pressure concentration to remove redundant phosphorus oxychloride, adding water, quenching, extracting with an organic solvent, drying, and concentrating to obtain the product 4,5,6-trichloropyrimidine.
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Paragraph 0027-0028
(2020/08/02)
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- Synthesis of 2-Monochloropanol Fatty Acid Esters and Their Acute Oral Toxicities in Swiss Mice
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A novel synthetic route was designed, developed, and utilized to synthesize six high-purity 2-monochloropropanediol fatty acid esters (2-MCPD esters), a group of potential processing-induced food contaminants. A chlorine atom was introduced to C-2 of a diethyl malonate molecule, which was reduced by NaBH4 and followed by esterification using fatty acids. The reaction products were isolated and purified using silica gel columns to obtain three 2-MCPD monoesters and three diesters at about 50-54% and 56-59% yields, respectively. In addition, 2-MCPD monopalmitate and dipalmitate were examined for their acute oral toxicities in Swiss mice. The LD50 values of 2-MCPD mono- and dipalmitate were greater than 5000 mg/kg body weight (BW), along with detectable nephrotoxicity and testicular toxicity. The results of this study may promote future investigation of MCPD ester toxicology and detection.
- Zhang, Zhongfei,Yang, Puyu,Gao, Boyan,Huang, Guoren,Liu, Man,Yu, Liangli Lucy
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p. 3789 - 3795
(2019/04/10)
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- Efficient α-chlorination of carbonyl containing compounds under basic conditions using methyl chlorosulfate
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An efficient method for the α-chlorination of ketones under basic conditions is described using methyl chlorosulfate. Its applicability for the chlorination of other functional groups has also been studied and it is equally useful for the synthesis of α-chloroesters and amides. Methyl chlorosulfate is described for the first time as a positive chlorine source. Some aldol reactions which occur during the chlorination of some substrates are also reported.
- Silva, Saúl,Maycock, Christopher D.
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supporting information
p. 1233 - 1238
(2018/02/27)
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- PROCESS FOR PREPARING (E)-(5,6-DIHYDRO-1,4,2-DIOXAZINE-3-YL) (2-HYDROXYPHENYL) METHANONE O-METHYL OXIME
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A process for preparing (E)-(5,6-dihydro-l,4,2-dioxazin-3-yl)(2- hydroxyphenyl)methanone O-methyl oxime is described which includes: (i) reacting benzofuran-3(2H)-one O-methyl oxime (1) with at least one nitrite selected from n-butyl nitrite and tert-butyl nitrite, in the presence of a metal alkoxide to form (2Z,32)-2,3-benzofuran-dione O3-methyl dioxime (2) as the predominant isomer; (ii) reacting the (2Z,3Z)-2,3-benzofuran-dione O -methyl dioxime (2) with 2- haloethanol to form (2Z,3Z)-benzofuran-2,3-dione 02-(2-hydroxyethyl) O3 -methyl dioxime (3); and (iii) reacting the (2Z,3Z)-benzofuran-2,3-dione 02-(2-hydroxyethyl) and -methyl dioxime (3) with an acid to form (E)-(5,6-dihydro-l,4,2-dioxazin-3-yl)(2- hydroxyphenyl)methanone (9-methyl oxime (4);
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Paragraph 0068
(2016/12/22)
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- Fluorine gas for life science syntheses: Green metrics to assess selective direct fluorination for the synthesis of 2-fluoromalonate esters
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Optimisation and real time reaction monitoring of the synthesis of 2-fluoromalonate esters by direct fluorination using fluorine gas is reported. An assessment of green metrics including atom economy and process mass intensity factors, demonstrates that the one-step selective direct fluorination process compares very favourably with established multistep processes for the synthesis of fluoromalonates.
- Harsanyi, Antal,Sandford, Graham
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supporting information
p. 3000 - 3009
(2015/05/27)
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- A Convenient Synthesis of 2-Fluoro- and 2-Chloromalonic Esters Mediated by Hypervalent Iodine
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Direct fluorination of malonic esters with a reagent system of iodosylbenzene and Et3N·5HF gave the corresponding 2-fluoromalonic esters in good to high yields. Direct chlorination using iodosylbenzene and hydrochloric acid also provided the 2-chloromalonates in high yields.
- Kitamura, Tsugio,Muta, Kensuke,Oyamada, Juzo
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p. 3241 - 3245
(2015/10/19)
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- PROCESS FOR PREPARING FLUOXASTROBIN
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A process for preparing fluoxastrobin, including: (i) reacting benzofuran-3(2H)-one O-methyl oxime (10) with an alkyl nitrite in the presence of an acid to form (3E)-2,3-benzofuran-dione O3-methyl dioxime (11A) as a predominant isomer; (ii) reacting(3E)-2,3-benzofuran-dione O3-methyl dioxime (11A) with 2-haloethanol to form (3E)-benzofuran-2,3-dione O2-(2-hydroxyethyl) O3-methyl dioxime (12A); and (iii) reacting(3E)-benzofuran-2,3-dione O2-(2-hydroxyethyl) O3-methyl dioxime (12A) with a base to form (E)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(2-hydroxyphenyl)methanone O-methyl oxime (13) (iv) reacting a 4,6-di-halo-5-fluoro-pyrimidine (5), wherein X1 is halogen, with (E)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(2-hydroxyphenyl)methanone O-methyl oxime (13), in the presence of a solvent and optionally in the presence of a base, to form an (E)-(2-((6-halo-5-fluoropyrimidin-4-yl)oxy)phenyl)(5,6-dihydro-1,4,2-dioxazin-3-yl)methanone O-methyl oxime (14): (v) reacting the (E)-(2-((6-halo-5-fluoropyrimidin-4-yl)oxy)phenyl)(5,6-dihydro-1,4,2-dioxazin-3-yl)methanone O-methyl oxime (14) with 2-chlorophenol, in the presence of a solvent and optionally in the presence of a base, to form fluoxastrobin:.
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Paragraph 0046
(2015/02/02)
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- A simple, mild, and efficient method for the preparation of α,α-dichloroketones with DCDMH catalyzed by ammonium chloride
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New process that can selectively prepare α,α-dichloro ketones from various ketones with 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) using ammonium chloride as a catalyst is reported. The effects of ammonium salts, solvents, DCDMH, and reaction temperature were investigated. Under the optimal condition, most of α,α-dichlorinated products were selectively obtained in 86-98% yield.
- Zheng, Zubiao,Han, Bingbing,Cheng, Peng,Niu, Jiangxiu,Wang, Aidong
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p. 9814 - 9818
(2015/01/09)
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- Mild and efficient α-chlorination of carbonyl compounds using ammonium chloride and oxone (2KHSO5·KHSO4· K2SO4)
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A simple protocol for the α-monochlorination of ketones and 1,3-dicarbonyl compounds utilizing NH4Cl as a source of chlorine and Oxone as an oxidant in methanol without catalyst is presented. The reaction proceeds at ambient temperature in yields ranging from moderate to excellent.
- Swamy, Peraka,Kumar, MacHarla Arun,Reddy, Marri Mahender,Narender, Nama
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supporting information; experimental part
p. 432 - 434
(2012/06/01)
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- Process For Preparing Chlorinated Carbonyl Compounds In Jet Loop Reactors
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The present invention relates to a process for preparing chlorinated or partly chlorinated carbonyl compounds, which comprises reacting unchlorinated or partly chlorinated carbonyl compounds with a chlorinating agent in a jet loop reactor.
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Page/Page column 3
(2008/12/05)
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- Rapid and catalyst-free α-halogenation of ketones using N-halosuccinamides in DMSO
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α-Halogenation of various carbonyl compounds such as β-keto-esters, cyclic ketones, and lactams with N-halosuccinamides (NBS, NCS, NIS) in the presence of DMSO proceeded very smoothly to give the corresponding α-monohalogenated products in good to excellent yields with high selectivity under catalyst-free conditions. Copyright Taylor & Francis Group, LLC.
- Sreedhar,Reddy, P. Surendra,Madhavi
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p. 4149 - 4156
(2008/03/13)
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- Conversion of nucleophilic halides to electrophilic halides: Efficient and selective halogenation of azinones, amides, and carbonyl compounds using metal halide/lead tetraacetate
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AlCl3/Pb(OAc)4 and ZnBr2/Pb(OAc) 4 are efficient electrophilic N- and α-C-halogenating agents. A variety of azinones, amides and carbonyl compounds were chemoselectively and regioselectively N-, or α-C-halogenated in good to excellent yield using AlCl3/Pb(OAc)4 and ZnBr2/Pb(OAc)4 in acetonitrile. Georg Thieme Verlag Stuttgart.
- Kim, Jeum-Jong,Kweon, Deok-Heon,Cho, Su-Dong,Kim, Ho-Kyun,Lee, Sang-Gyeong,Yoon, Yong-Jin
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p. 194 - 200
(2007/10/03)
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- 2-Chloropyridazin-3(2H)-ones as electrophilic chlorinating agents: Effective α-chlorination of active methylene/methine compounds
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2,4,5-Trichloro- (2a) and 2,4-dichloro-5-methoxypyridazin-3(2H)-one (2b) are novel electrophilic chlorinating agents. α-Chlorination of active methylene/methine compounds with 2 in the presence of either Lewis or protonic acids in dichloromethane (for Lewis acid) or water (for protonic acid or none) at room temperature gave also selectively α-monochlorides and/or α,α-dichlorides in good to excellent yields.
- Park, Yong-Dae,Kim, Jeum-Jong,Cho, Su-Dong,Lee, Sang-Gyeong,Falck, J. Russell,Yoon, Yong-Jin
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p. 1136 - 1140
(2007/10/03)
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- Efficient microwave induced direct α-halogenation of carbonyl compounds
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A novel and direct method for the synthesis of α-halocarbonyl compounds using sequential treatment of carbonyl compounds with [hydroxy(tosyloxy)iodo]benzene followed by magnesium halides under solvent-free microwave irradiation conditions is described.
- Lee, Jong Chan,Park, Jin Young,Yoon, So Young,Bae, Yong Hun,Lee, Seung Jun
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p. 191 - 193
(2007/10/03)
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- One-Pot synthesis of 5-Alkylthio-3H-1,2-dithiole-3-thiones: Advantages and scopes
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The reaction of dialkyl malonate esters with P2S5/S8 in boiling xylene in the presence of 2-mercaptobenzothiazole/ZnO as catalyst produces 5-alkylthio-3H-1,2-dithiole-3-thiones as major identifiable product. Moderate yields were obtained with malonate esters of primary alcohols. The reaction fails with malonate esters of secondary alcohols. Regarding the substituent in position two, dialkyl malonates with groups such as CH3, Ph, CH2Ph, OCH3 and Cl afford the corresponding 4-substituted derivatives whereas with Br and NO2 do not give the expected products. Some mechanistic evidences are described.
- Aimar,De Rossi
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p. 1749 - 1755
(2007/10/03)
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- A Convenient Halogenation Procedure for the Preparation of α-Halocarbonyl Compounds
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Except for substituted acetophenones (p-Y-C6H4COCH3, Y=H, Br, CH3O), simple ketones, α-ketoesters and 1,3-diketones reacted smoothly with a preformed homogeneous mixture of hydrochloric acid and potassium permanganate in acetonitrile to give moderate to good yields of the corresponding α-chlorocarbonyl compounds.Mixtures of α-chloro- and α,α-dichlorocarbonyl compounds were obtained for substituted acetophenones.Brominations proceeded similarly with higher yields when the hydrochloric acid was replaced with hydrobromic acid. - Key words: α-chlorocarbonyl compounds; α-bromocarbonyl compounds; potassium permanganate; chlorination; bromination.
- Cheng, Sheng-Fan,Lin, Ching-Shan,Liu, Lilian Kao
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p. 309 - 312
(2007/10/03)
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- Mild Halogenation of Stabilized Ester Enolates by Cupric Halides
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The reactions of various stabilized ester enolates of 2-keto, 2-(alkoxycarbonyl), 2-phosphoryl, and 2-(benzenesulfonyl) esters with cupric chloride or cupric bromide have been examined.The reactions lead to 2-halo esters in good to excellent yields under mild condition.Enolates which contain an unsaturated functionality such as a double bond, a triple bond, or an allylic or a benzylic moiety react with high chemoselectivity.
- Shi, Xiao-Xin,Dai, Li Xin
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p. 4596 - 4598
(2007/10/02)
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- CHLORINATION OF ACETYLACETONE AND ACETOACETIC AND MALONIC ESTERS.
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To develop a laboratory procedure for the one-stage chlorination of ME, AAcE, and AA, the authors studied the action of gaseous chlorine on these compounds. We found that when the chlorination is carried out at 55-60 degree C, the formation of side products is reduced to a minimum. The reaction begins at 35-40 degree C, and then proceeds exothermally, and it can be easily controlled by external cooling or by decrease in the rate of chlorine input. The optimal reaction regime lies within 55-60 degree C. Further increase in temperature leads to the formation of trichloro derivatives and more extensive chlorination. If the chlorination reaction is carried out for 7-8 h at 55-60 degree C, dichloro derivatives of ME, AAcE, and AA are mainly formed, and the yields in the most favorable experiments are equal to (%): DCM 93, DCAAc 87, DCAA 75. Under these conditions, only inappreciable amounts of monochloro derivatives and more extensively chlorinated products are present in the reaction mixture. The authors isolated mono-, di-, and trichloro derivatives of ME, AAcE and AA.
- Amriev,Velichko,Abdulkina
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p. 2318 - 2322
(2007/10/02)
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- Addition of 2-Methylthio-5-pyrimidinol and 5-Methoxy-2-pyrimidinethiol to the Acetylene Triple Bond
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Reaction of 2-methylthio-5-pyrimidinol (I) with 2-methylthio-5-(2-propionyloxy)pyrimidine (II) in the presence of sodium methoxide gave cis-1,3-bis(2-methylthio-5-pyrimidinyloxy)-1-propene (IIIa) and 6-methyl-2-methylthiofuro-pyrimidine (IV).On addition of I to 2-propinol cis-3-(2-methylthio-5-pyrimidinyloxy)-2-propenol (V) and the isomeric 2-(2-methylthio-5-pyrimidinyloxy)-2-propenol (VI) were formed.The latter when converted to chloro derivative VII was reacted with I to give 2,3-bis(2-methylthio-5-pyrimidinyloxy)-1-propene (VIII).From 1,3-dibromo-2-propanoland I 1,3-bis(2-methylthio-5-pyrimidinyloxy)-2-propanol (XI) was prepared which was converted to 1,3-bis(2-methylthio-5-pyrimidinyloxy)-2-bromopropane (XII) and then dehydrobrominated to a mixture of cis- and trans-1,3-bis(2-methylthio-5-pyrimidinyloxy)-1-propene (IIIa, IIIb). 5-Methoxy-2-pyrimidinethiol (XIV) reacts with 2-propinol similarly as I under formation of cis-3-(5-methoxy-2-pyrimidinylthio)-2-propenol (XV) and 2-(5-methoxy-2-pyrimidinylthio)-2-propenol (XVI).Compound I when reacting with 1-chloromethyloxirane gives both 1,2-epoxy-3-(2-methylthio-5-pyrimidinyloxy)propane (X) and 1-chloro-3-(2-methylthio-5-pyrimidinyloxy)-2-propanol (XIII), depending on reaction conditions.
- Budesinsky, Zdenek,Budesinsky, Milos,Svab, Alois
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p. 2254 - 2262
(2007/10/02)
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- HALOGENATION OF CONJUGATED CARBANIONS BY CARBON TETRACHLORIDE. SYNTHESIS OF α-HALOGENOCARBONYL COMPOUNDS.
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In aprotic bipolar solvents the sodium enolates of acetylacetone and acetoacetic, cyanoacetic, and malonic esters reacts with carbon tetrachloride to form the corresponding α-chlorocarbonyl compounds.Under the conditions of synthesis α-chlorocyanoacetic ester is converted further into triethyl 1,2,3-tricyano-1,2,3-cyclopropanetricarboxylate.In the case of diethyl malonate, increase in the reaction time and in the excess of the chlorinating agent leads to the formation of the α,α-dichloro derivative.
- Terpigorev, A. N.,Shcherbin, M. B.,Bazanov, A. G.,Tselinskii, I. V.
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p. 2175 - 2178
(2007/10/02)
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