Preparation Of Dimethyl Research Articles

ChemInform Abstract: Iron(III) Tosylate in the Preparation of Dimethyl and Diethyl Acetals from Ketones and β‐Keto Enol Ethers from Cyclic β‐Diketones.

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Synthesis of Dimethylphosphinyl-substituted α-Amino(aryl)methylphosphonic Acids and Their Esters

Abstract Dimethylphosphinylmethylamine (1) and its aldimines 2 were used for the preparation of dimethyl and diethyl α-amino(aryl)methylphosphonates 3a - l via imine hydrophosphonylation and Kabachnik-Fields reaction. Their acid hydrolysis gave rise to the corresponding α-aminophosphonic acids 4a - e. Compounds 3 and 4 have two different phosphorus-containing groups - phosphonyl and dimethylphosphinyl - and might have interesting biological activity.

Iron(III) Tosylate in the Preparation of Dimethyl and Diethyl Acetals from Ketones and β -Keto Enol Ethers from Cyclic β -Diketones

An efficient method for conversion of ketones to their corresponding dimethyl and diethyl acetals and of cyclic β-diketones into β-keto enol ethers using Fe(OTs)3 as a catalyst is described.

The synthesis and characterisation of novel dimethyl- and diphenyl-silanediolates

Dimethyl- and diphenylsilanediolates are key intermediates in the preparation of dimethyl- and diphenyl-siloxane polymers. Both dimethyl- and diphenylsilanediolates R2Si(OM)2, where R = Me or Ph, and M = Li, Na and K were synthesised by the reaction between dimethyl- and diphenylsilanediol and a metal or metal hydride (M/MH where M = Li, Na and K). The silanediolates were characterised by 29Si, 13C and 1H NMR, FTIR and mass spectroscopy.

The Preparation of Dimethyl α -Hydroxyphosphonates and the Chemical Shift Non-Equivalence of Their Diastereotopic Methyl Ester Groups

Dimethyl α -hydroxyalkyl-, α -hydroxybenzyl-, α -hydroxyfurfuryl-, and α -hydroxy-α -thienylmethyl-phosphonates have been prepared in good yield by the alumina-catalyzed reaction of dimethyl phosphite with the corresponding alkanals, aryl aldehydes (or aryl methyl ketones), furfuraldehyde, and 2- or 3-thiophenecarboxaldehyde, respectively, thus confirming the general utility of this synthetic procedure. The 1H and 13C nmr spectra of the products exhibit characteristic chemical shift non-equivalence of the diastereotopic methyl ester groups, for which a tentative order of non-equivalence is reported and discussed.

Preparation of dimethyl ( R)- and ( S)-2-(2-hydroxyphenyl)-2-hydroxyethylphosphonate derived from salicylaldehyde via resolution using ( S)-methoxyphenylacetic acid (MPA)

The efficient preparation of both enantiomers of dimethyl δ,β-dihydroxyethylphosphonate 2 has been achieved from salicylaldehyde as a starting material, through the resolution of dimethyl (±)-2-(2- O-benzylphenyl)-2-hydroxyethylphosphonate 4 using ( S)-methoxyphenylacetic acid (MPA). The absolute configuration was assigned by the Dale and Mosher approach using extended Newman projections and ab initio calculations.

Preparation of dimethyl ( R)- and ( S)-2-(2-aminophenyl)-2-hydroxyethylphosphonate from anthranilic acid

An efficient synthesis of both enantiomers of dimethyl δ-amino-β-hydroxyethylphosphonate 6 has been achieved starting from anthranilic acid, through the resolution of dimethyl (±)-2-(2- N, N-dibenzylaminophenyl)-2-hydroxyethylphosphonate 9 with ( S)- O-methylmandelic acid. The absolute configuration of the enantiomers 9 was assigned by the Dale and Mosher approach using the extended Newman projections and molecular mechanics.

Preparation of Dimethyl and Chloro/Methyl Complexes of Platinum(II) Supported by -Diimine Ligands: Trends in the Ease of Oxidation to Platinum(IV)

Preparation of Dimethyl and Chloro/Methyl Complexes of Platinum(II) Supported by -Diimine Ligands: Trends in the Ease of Oxidation to Platinum(IV)

Preparation of Dimethyl and Chloro/Methyl Complexes of Platinum(II) Supported byα-Diimine Ligands: Trends in the Ease of Oxidation to Platinum(IV)

α-Diimine ligands react with the platinum(II) alkyl complexes [(Me2S)PtMe2]2 and (Me2S)2PtClMe to form (RDABR′)PtMe2 and (RDABR′)PtClMe (RDABR′=RN=CR′−CR′=NR; R=2,6-Me2Ph, 2,6-(CHMe2)2Ph, 3,5-Me2Ph, 3,5-(CF3)2Ph, C6H11; R′=Me, H). The oxidation of these complexes with Cl2, I2, N-chlorosuccinimide, [PtCl6]2− and (TMEDA)PtMe2I2 has been investigated. Attempts to determine the oxidation potentials of the PtII complexes electrochemically yielded only irreversible one-electron oxidations. However, a qualitative ordering of increasing difficulty of oxidation has been determined for the series (RDABR′)PtMe2<(RDABR′)PtClMe<(RDABR′)PtCl2≪(RDABR′)PtMe(solvent)]+. The oxidation proceeds via a two-electron inner-sphere electron transfer from a bridged binuclear intermediate. The oxidation of (RDABR′)PtMe2 by (TMEDA)PtMe2I2 exhibits characteristic third-order kinetics, first-order each in [PtII], [PtIV] and [I−]. Oxidation by a one-electron process in MeCN solution results in a rapid subsequent disproportionation to PtIIMe and PtIVMe3 cations with MeCN occupying the fourth or sixth coordination sites. Single-crystal X-ray structure determinations for [(2,6-Me2PhDABMe)PtMe3(MeCN)]+[PtCl6]0.5(MeCN) and [(CyDABH)PtMe3(MeCN)]+[PtCl6]0.5(MeCN) are reported.

Dimethyl (±)-2,3-Dimethylcubane-1,4-dicarboxylate

The preparation of dimethyl (±)-2,3-dimethylcubane-1,4-dicarboxylate (2), in multigram quantities, from 3-methylcyclopent-2-en-1-one (3), in an overall yield of c. 26%, is presented.

Preparation of Dimethyl 7‐Oxobicyclo[2.2.1]heptane‐exo‐2, exo‐3— dicarboxylate. An Easy Route to Functionalized Norbornane Derivatives and Cage Compounds

A four‐step preparation of dimethyl 7‐oxobicyclo[2.2.1]‐heptane‐exo‐2, exo‐3‐dicarboxylate (4) in satisfactory yield from the readily available 6,6‐dimethylfulvene and maleic anhydride is described. Compound 4 represents a well‐functionalized intermediate for the synthesis of norbornane derivatives which is used for an improved synthesis of the tricyclic diester 7, precursor of the cage compound 8. An alternative approach to diester 7 from dimethyl 7‐isopropylidenebicyclo[2.2.1]heptane‐exo‐2, exo‐3‐dicarboxylate (2) is also discussed.

Synthesis and structure of the dimethylamide of chlorothioformic acid and its reaction with potassium thiocyanate

1. Methods for the preparation of dimethyl- and diethylamides of chlorothioformic acid of greater purity based on the reaction of tetraalkylthiuram disulfides with sulfuryl chloride are presented. 2. Reaction of the dimethylamide of chlorothioformic acid with potassium thiocyanate proceeds through a fast dimerization of the initially produced dimethylaminothiocarbonylisothiocyanate, followed by 1,3 (N→S) migration of the dimethylaminothiocarbonyl group to give 2-dimethylamino-4-dimethylaminothiocarbonylthio-1,3,5-thiadiazine-6-thione.

ChemInform Abstract: SOME REACTIONS OF A 4‐(1‐CHLOROETHYL)‐1,4‐DIHYDROPYRIDINE

AbstractUmsetzung des aus den Komponenten (II) und (III) erhältlichen Dihydropyridins (Ia) mit entsprechenden Nucleophilen liefert die Dihydroazepine (IVa) (daneben das Pyrrol (V)), (IVb) bzw. (IVc).

Some reactions of a 4-(1-chloroethyl)-1,4-dihydropyridine

The preparation of dimethyl 4-(1-chloroethyl)-1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate and its reaction with nucleophilic reagents are described. Potassium cyanide, potassium succinimide, or methanolic triethylamine gave, stereospecifically, 4,5-dihydroazepines in which substituents at C(4) and C(5) are trans, whereas potassium thiocyanate afforded only the corresponding 4-(1-thiocyanatoethyl)-1,4-dihydropyridine. Sodium hydrosulfide afforded a mixture of 8-thia-2-azabicyclo[3.2.1]oct-3-ene-4,7-diesters epimeric at C(7), whereas potassium carbonate in aqueous dimethyl sulfoxide yielded an 8-oxa-2-azabicyclo-[3.2.1]oct-3-ene-4,7-diester. The stereochemistry of these bicyclic compounds is established using nmr spectroscopy. In acid media, dimethyl 2,5,7-trimethylazepine-3,6-dicarboxylate and a 4-methoxy-4,5-dihydroazepine rearranged to give 1,4-dihydropyridine derivatives; a mechanism for this ring contraction is suggested.

A Convenient Preparation of Dimethyl and Diethyl Oxaloacetate

Abstract The title compounds have usually been prepared as their sodium salts by Claisen condensations with acetic and oxalic acid esters and strong bases such as sodium alkoxides as catalysts.1,2 In this communication we want to present a very mild and convenient route to both title compounds starting from the corresponding methyl or ethyl acetylenedicarboxylates.

The preparation of dimethyl(7‐2H3 2‐oxoheptyl) phosphonate

AbstractDimethyl (7‐2H3 2‐oxoheptyl) phosphonate 4 has been prepared from 2H3 methyl iodide. The phosphonate should be a useful reagent for the synthesis of deuterium labelled prostaglandins and thromboxanes.

Preparation of Dimethyl(4-nitro- and 4-chloro-benzyl)alkyl ammonium Chloride and their Physico-chemical, Antibacterial and Antifungous Properties

The quaternary salts from N, N-dimethylalkyl-amines (R: dodecyl, hexadecyl and octadecyl)and 4-nitro- or 4-chloro-benzylchloride were prepared and their physico-chemical, antibacterial and antifungous properties were studied. The results obtained were as follows.(1) 4-Chloro-derivatives were supetior to 4-nitro-derivatives in such surface active properties as lowering of surfae tension, emulsifying of liquid paraMn and wetting of cloth.(2) The long alkyl chain derivatives were more powerful in lowering of surface tension, increasing of 'a' mmounts of solubilized Orange OT, emulsifying and wetting as compared with the short chain'derivatives.(3) A linear telationship Was observed between alkyl chain length and log CMC for a homologous series.(4) The growth retardati6n by the homologous compounds for mildew became progressively greater as. the carbon number of straight chain decreased.(5) The substituents, chloro and nitro group on benzene ring decreased antibacteria aRd antimildew actions against our expectations.

Preparation of dimethyl .alpha.,.alpha.'-bis(diethylphosphono)adipate and .alpha.,.alpha.'-bis(diethylphosphono)adipamide

Preparation of dimethyl .alpha.,.alpha.'-bis(diethylphosphono)adipate and .alpha.,.alpha.'-bis(diethylphosphono)adipamide

Preparation of Dimethyl (5-nitro-1-naphthylmethyl) alkylammonium Chlorides and Their Surfaceactive, Antibacterial and Antifungous Properties

The following quaternary ammonium salts were synthesized. CH3 R -14 -C112- Cl CH3 -NO2R; dodecy1-(sampleNo.1); hexadecy1-(No.2); octadecy1(No.3). The suroce active properties of the sesamples such as suface tension, viscosity, electrolytic conductivity, solubilization emulsification and wetting as well as antibacterial and antmusty properties were studied to give the following results.The results obtained were as follows.(1)Surface activities of these samples follow according to the order of sample3>2>1.(2).Studies on the surface tension and electrolyticconductivity as a function of concentration of the samples indicated that CMC of samples2 and 3 were O.017 and O.0109/100ml, respectively.(3)Sample lwas excellent as the antibacterial and antifungous agents; sample 2 was less activite and sample 3 was the least active of the three.

On the Preparation of Dimethyl 4-Methylpyridine-3,5-dicarboxylate.

On the Preparation of Dimethyl 4-Methylpyridine-3,5-dicarboxylate.