Synthesis of Methyl 2‐Methylazulene‐3‐carboxylate in the Presence of Molecular Sieves and Reaction with N‐Bromosuccinimide

The preparation of methyl 2‐methylazulene‐1‐carboxylate (1) was carried out in the presence of molecular sieves to obtain a good yield. The product was subjected to bromination under different reaction conditions to obtain methyl 1‐bromo‐2‐methylazulene‐1‐carboxylate (2) and methyl 1‐bromo‐2‐(bromomethyl) azulene‐1‐carboxylate (3).     

Direct and Convenient Method of Regioselective Benzylation of Methyl α‐D‐Glucopyranoside

A facile and convenient method for the direct preparation of methyl 2,3,6‐tri‐O‐benzyl‐α‐D‐glucopyranoside (2) by the regioselective benzylation of methyl α‐D‐glucopyranoside (1) with benzyl bromide in the presence of mild bases K₂CO₃ and KOH (1∶1) without solvents is reported.     

Selective Nitroxylation of Adamantane Derivatives in the System Nitric Acid–Acetic Anhydride

Russian Journal of Organic Chemistry - A number of new nitroxyadamantanes have been synthesized by nitroxylation of the corresponding substrates with nitric acid in acetic anhydride. High...     

Synthesis of Functionalized 1‐Azadienes by Reaction of 2,6‐Dimethylphenyl Isocyanide and Acetylenic Esters in the Presence of CH Acids

The adducts produced in the reaction between 2,6‐dimethylphenyl isocyanide and acetylenic esters were trapped by 3‐chloroacetylacetone, dialkyl 2‐chloromalonates, or dimethoxy methoxymalonate to produce highly functionalized 1‐azadienes in good yields.     

Polymerization of Methyl Methacrylate in the Presence of N-Acetyl-ε-aminocaproic Acid Acetylamide

The effect of N-acetyl--aminocaproic acid acetylamide on radical polymerization of methyl methacrylate initiated with lauroyl peroxide was studied.     

Polymerization of Methyl Methacrylate by the System Ribonucleic Acid–Water in the Presence of Carbon Tetrachloride and Copper(11) Ion

Polymerization of methyl methacrylate (MMA) was carried out in the presence of ribonucleic acid (RNA), water, carbon tetrachloride, and copper(II) ion. The overall activation energy for the polymerization is proportional to the square root of the amount of RNA. The rate increased at first with the amount of MMA, but then became independent of the amount of MMA.

Polymerization was inhibited by the presence of air. Carbon tetrachloride and copper(II) ion are able to give RNA the ability to initiate polymerization. Conversion of MMA is accelerated by the addition of tertiary amine derivatives instead of carbon tetrachloride.     

A Regioselective Synthesis of Tetrahydrobenzodiazepin‐5‐ones via the Schmidt Rearrangement of Quinolones

Abstract

The regioselective synthesis of 2,3,4,5‐tetrahydro‐1H‐1,4‐benzodiazepin‐5‐ones by the Schmidt rearrangement of 1,2,3,4‐tetrahydro‐4‐quinolones with oxygen substituents at C‐8 is described.     

Semibatch Emulsifier-free Emulsion Copolymerization of Methyl Methacrylate and n-Butyl Acrylate in the Presence of 2-Hydroxyethyl Methacrylate

ThemethodsofimProvingthestabilityofemulsifier-freeemulsionpolymerizationhavebeenreportedinliteraturet(a)choosingionizableinitiators,suchaspotassiumpersulfate'andazo-bis(isobutyramidinehydrochloride)';(b)copolymerizationwithhydrophiliccomonomers,whichinvolvestheionictypesuchascarboxylicmonomers',sulfoderivativesofvinylmonomers',andthenonionictypesuchasglycidylmethacrylate';(c)copolymerizationwithsurface-activemonomers,suchassulfodecylslyrylether';(d)addingorganicsolventstothesystem,suchasmethano…     

“Conjugate” Substitution of Hydrogen in the Methyl Group of Pentabromotoluene in the Presence of Strong Bases

The reactions of pentabromotoluene with i-PrONa or t-BuONa in pyridine give N-(pentabromobenzyl)pyridinium bromide and a mixture of isomeric tetrabromotoluenes. In the presence of bromine or carbon tetrabromide, the reductive debromination is blocked, and the reactions involve exclusively substitution of hydrogen in the methyl group of pentabromotoluene by the pyridinium residue.     

De‐agglomeration of Silica Nanoparticles in the Presence of Surfactants

The effect of the type of surfactant and pH on de‐agglomeration of a hydrophilic silica nano‐powder in a high shear mixer was investigated. It has been found that the presence of surfactant does not affect the general pattern of de‐agglomeration characterized by the transition of a single modal aggregates size distribution with the median of 10 µm, through a bi‐modal distributions with the second median of the order of 100 nm to a single modal distribution with the median of the order of 100 nm. None of the investigated surfactants enabled de‐agglomeration of the nano‐powder into a primary nanoparticle.

At pH=4, breakage of large secondary aggregates was enhanced by the addition of PEG and PVP, whereas the addition of SDS slowed down de‐agglomeration. The final aggregates were larger in all suspensions containing surfactant than in surfactant free suspensions. At pH=9 all surfactants drastically reduced de‐agglomeration rate without affecting the size of the primary aggregates. PEG induced bridge flocculation of the primary aggregates leading to a drastic change of the rheology of suspension.     

Efficient Regioselective Ring Opening of Oxiranes with Thioacids in the Presence of β‐Cyclodextrin in Water

A mild and convenient synthesis of β‐hydroxy thioesters has been achieved by the regioselective ring opening of oxiranes using thioacetic acid and thiobenzoic acid in the presence of β‐cyclodextrin in water at room temperature. β‐Hydroxy thioesters are realized in high yields, and β‐cyclodextrin can also be recovered and reused.     

Solvent‐Free Synthesis of Benzothiazolines in the Presence of Alumina

o‐Aminothiophenol reacted with ketones and β‐keto esters in the presence of alumina under mild and solvent‐free conditions to afford the corresponding benzothiazolines in high yields. Alumina can be reused for subsequent reactions without any loss of the activity.     

Synthesis of Polyvinylacetate‐Sodium Montmorillonite Hybrids by Emulsion Polymerization in the Presence of Anionic Surfactants

The emulsion polymerisation of vinyl acetate (VAc) in presence of sodium dodecylsulphate (SDS) and sodium montmorillonite (NaMMT) is used in order to achieve polymer‐clay hybrids. The influence of the polyvinylacetate (PVAc), SDS, and PVAc‐SDS complex on the NaMMT structure also was investigated. The VAc emulsion polymerization rate exhibits a maximum as the NaMMT concentration increases. The XRD patterns correspond to hybrids with intercalated structure. If a water soluble comonomer, ammonium sulphato ethylmethacrylate (ASEMA) is used for copolymerization with VAc, a exfoliated hybrid structure (from XRD spectra) is obtained. The solid materials were analysed by TGA, FTIR, XRD, SEM, and TEM.     

Stereo‐ and Regioselective Thiolysis of 1,2‐Epoxides in Water

A simple, efficient, stereoselective, and highly regioselective procedure for the synthesis of β‐hydroxy sulfides by thiolysis of various 1,2‐epoxides in water as a solvent, using no catalyst and under very mild conditions, is described.     

Mild and Efficient Deoxygenation of Amine‐N‐oxides with MoCl5/NaI System

The MoCl₅/NaI system was found to be a new reagent for deoxygenation of various amine‐N‐oxides to the corresponding amines in good to excellent yields under mild conditions.     

Note a Kinetic Study of the Photopolymerization of N,N Methylenebisacrylamide Initiated by N‐Bromo‐Succinimide in the Presence and Absence of Isopropyl Alcohol

The photopolymerization of N,N′‐methylenebisacrylamide has been studied with N‐bromosuccinimide as photoinitiator in the presence and absence of isopropyl alcohol (ISP). The rate of polymerization in the presence of ISP was found to be very high, and this is explained on the basis of the relative reactivities of the initiating radicals. A probable mechanism consistent with the observed results is proposed and discussed.     

Ultrasound‐Assisted Synthesis of β‐Enaminonitriles in the Presence of Base

Application of ultrasound shows significant rate enhancement for the synthesis of β‐enaminonitriles in the presence of base. The role of various homogeneous and heterogeneous bases/solvents was also studied for the reaction, and potassium t‐butoxide/t‐butyl alcohol combination was found to give the best result at room temperature.     

Debromination of α‐Bromoketones and vic‐Dibromides Using Indium in the Presence of Carboxylic Acid

Abstract

The debromination of α‐bromoketones and vic‐dibromides using indium metal in the presence of acetic acid at room temperature effectively afforded the corresponding ketones in excellent yield.     

Synthesis and Characterization of Ti-ZSM-5 in a Non-alkaline Medium in the Presence of Fluoride Ions

Ti-ZSM-5 was synthesized by hydro thermal crystallization in the presence of fluoride via using a non-alkaline medium. pH values were 5~7. SEM showed perfect Ti-ZSM-5 crystals and a large single crystal growing from the favourable medium. Substitution of titanium for silicon in the ZSM-5 framework led to a decrease of crystal size and of the length/width ratio. Electron microprobe analysis indicated a homogeneous distribution of titanium in the ZSM-5 framework. The unit cell parameters of the Ti-ZSM-5 determined by XRD increased with an increase in titanium content in the framework. TiO4tetrahedron vibrations were found in the IR spectrum. Si(1Ti) peakwas seen in the 29Si MAS NMR spectrum at -1O1ppm(from TMS) and 13CMAS NMR analysis verified the effect of (C3H7)4N F- occluded in thechannels. XPS study on the precursors, calcined and H2O2 adsorbed Ti-ZSM-5 was performed and some interesting results were observed.     

Remarkably Accelerated Regioselective Hydrogenolysis of Terminal Epoxides in the Presence of CoC12 or NiSO4

The rate of atmospheric pressure hydrogenolysis of terminal epoxides over palladium-charcoal to the corresponding methyl alcohols could be remarkably accelerated by introduction of CoC12 or NiSO4.