Reactions of 1-Cyanoimidazole and 1-Cyanobenzimidazole with Aliphatic Alcohols

Alkyl imidazole-1-carboximidates and alkyl benzimidazole-1-carboximidates were synthesized by reaction of 1-cyanoimidazole and 1-cyanobenzimidazole with aliphatic alcohols. The reaction time and the product yield depend on the structure of the alcohol.     

Reaction of 1-(alk-1-ynyl)-1-halocyclopropanes with alcohols and phenol in KOH/DMSO as a method for the synthesis of 2-alkoxy-1-alkynyl- and 1-alkynyl-2-phenoxycyclopropanes

The reaction of 1-(alk-1-ynyl)-1-halocyclopropanes with alcohols or phenol in KOH/DMSO at 80–100 °C leads to the corresponding alkynylalkoxy- and alkynylphenoxycyclopropanes in up to 80% yield. These reactions proceed through the intermediate formation of conjugated alkynylcyclopropenes capable of the in situ addition of alcohols at the double bond of the cyclopropene fragment. Regio- and stereoselectivity of the process is defined by the nature of substituents in the starting cyclopropanes and the structure of alcohols used.     

Epimeric 1-hydroxy-1-substituted indolizidines

Epimeric mixtures of 1-hydroxy-1-phenylindolizidines and 1-hydroxy-1-methylindolizidines were obtained from the reaction of 1-ketoindolizidine with the appropriate Grignard reagent. The resulting alcohols were separated by chromatographic and distillation techniques. Infrared data and physical constants were utilized for the elucidation of the structures. Structural assignments of the indolizidinium iodides were made on the basis of nmr data.     

Syntheses of Carboxylic Acids from 1, 1-Dichloroehylene

Many β-alkyl- and β-arylpropionic acids are readily obtainable by the reaction of secondary or tertiary alcohols, esters of these, or olefins with the inexpensive 1, 1-dichloroethylene in sulfuric acid. The success of the synthesis depends on the bulk and energy of the carbonium ion intermediate formed from the alcohols or olefins. With carbonium ions having one H atom attached to the carbonium C atom, electrophilic substitution of the 1,1-dichloroethylene takes place to a small extent. Dicarboxylic acids and carboxylic acids with higher molecular weights are sometimes formed as a result of side reactions.     

Tertiary Acetylene Alcohols Prepared from 1-Octadecyne

Synthesis of tertiary acetylene alcohols was developed based on 1-octadecyne treatment with butyllithium followed by reaction of 1-octadecynyllithium with aliphatic, aromatic, alicyclic, and terpene ketones.     

Poly-1-acryloylbenzotriazole as polyester and polyacrylamide precursor

1-Acryloylbenzotriazole was prepared and polymerized. The resulting poly-1-acryloylbenzotriazole gave pure polyacrylic esters and polyacrylamides by reaction under mild conditions with alcohols and amines.     

Cyclobutanones via the (1-Oxycyclopropyl)methanol Route

A variety of alcohols of the 1-oxycyclopropyl structure, prapared mostly from α-alkoxy-α,β-unsaturated ketnnes and esters by way of reductinn and Simmons-Smith reaction of the resultant α-alkoxyallyl alcohols, are shown to rearrange into cyclobutanones on acid treatment (cf. Scheme 1).     

Simple method for the preparation of esters from Grignard reagents and alkyl 1-imidazolecarboxylates

The reaction of Grignard reagents with alkyl imidazolecarboxylates, which were prepared from alcohols with carbonyl diimidazole, gave the corresponding esters in good to excellent yields. This method conveniently provides esters from alkyl halides and alcohols by C1-carbon chain extension.     

Synthesis of 1-benzofuran-2-carboxylates by reaction of 1-benzofuran with halomethanes and alcohols in the presence of iron compounds

Alkyl 1-benzofuran-2-carboxylates were obtained in quantitative yield by reaction of 1-benzofuran with halomethanes and alcohols in the presence of iron-containing catalysts both in the presence and in the absence of radical initiators.     

TfOH catalyzed synthesis of 1-substituted tetrahydrocarbazoles

Synthesis of 1-substituted tetrahydrocarbazole is accomplished by TfOH catalyzed reaction of 3-substituted indoles tethered with secondary and tertiary alcohols. The reaction was generalized for a variety of substrates and was extended to the synthesis of 2,3,3a,6-tetrahydro-1H-pyrido[3,2,1-jk]carbazole and carbazoles.     

Interaction of 2,2,6,6-tetramethylpiperidine-1-oxyl chloritewith alcohols

The kinetics of the oxidation of a series of alcohols (viz., ethanol, propan-2-ol, butan-1-ol, butan-2-ol, heptan-4-ol, decan-2-ol, propan-1,3-diol, butan-2,3-diol, cyclohexanol, benzyl alcohol, and borneol) with the oxoammonium salt 2,2,6,6-tetramethylpiperidine-1-oxyl chlorite in acetonitrile was studied by spectrophotometry. The products of oxidation of primary alcohols are the corresponding aldehydes and carboxylic acids, and the products of oxidation of secondary alcohols are ketones. The reaction rate is described by the second order equation. The rate constants and activation parameters were determined. The rate constant as a function of the alcohol nature is described by the one-parameter Taft equation.     

Significant Heterogeneous Carbonate Salt Catalyzed Acetylation of Alcohols via a Transesterification Process with Carbonate Salt‐activated Alcohol 1H NMR Evidence

Heterogeneous carbonate salt catalyzed acetylation of alcohols via a transesterification process has been developed. Various esters are furnished up to 97% yield. Established procedure is simple and air‐tolerant with readily available reagents. Ethyl acetate and isobutyl acetate are used as not only acetylating agents, but also reaction solvents in transesterification. Aliphatic linear alcohols, allylic alcohols and benzyl alcohols show high reactivities in the presence of 1 or 5 mol% Cs₂CO₃ at 125°C. Cesium carbonate can be recycled by pumping liquid phase out of reactor after reaction. During four cycle runs for reaction of 2‐phenylethanol and ethyl acetate, high yields of phenethyl acetate are provided (>60% yield). Based on experiments and ¹H NMR investigation, bifunctional catalysis is proposed, alcohol activated by carbonate ion is confirmed, and higher activity of catalytic amount than stoichiometric cesium carbonate is interpreted.     

Synthesis of 1-substituted-7-hydroxyquinolinium salts

The reaction of 7-acetoxyquinoline with trifluorosulfonate esters of primary alcohols in methylene chloride or acetonitrile, followed by acid hydrolysis, provides a general synthesis of 1-substituted-7-hydroxyquinolines, whose phenolate anions are fluorescent.     

A High Yield Method for Preparation of Potential Pesticides : Syntheses of 1-Alkoxy-Ethyl-N N-dialkyl Carbamates

A number of 1-alkoxy-ethyl-N, N-dialkyl carbamates have been prepared by reaction of the corresponding 1-chloro-ethyl-N, N-dialkyl carbamates with alcohols.     

Addition of tetrachloromethane to oct-1-ene initiated by amino alcohols

The kinetics and mechanism of an addition of CCl₄ to oct-1-ene initiated by amines, aromatic alcohols, and amino alcohols (structural analogs of ephedrin) were studied. The radical mechanism of the reaction was established by ESR using the technique of spin traps. Aromatic amino alcohols as initiators are more active than amines and aromatic alcohols of similar structure. They are more selective compared to the amines and aromatic alcohols and react with CCl₄ already at room temperature to form predominantly benzaldehyde. The scheme of initiation by aromatic amino alcohols of the addition of CCl₄ to olefins was proposed on the basis of the experimental data. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1565–1571, September, 2006.     

Iodocyclization of cis-1-R-2-allylcyclopentan-1-ols

Derivatives of cyclopenta[b]tetrahydrofurans are formed as a result of the iodocyclization of cis-1-R-2-allylcyclopentan-1-ols. The iodocyclization reaction of unsaturated alcohols is described by a kinetic equation of the second order (the first order for each of the reagents).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1608–1610, December, 1988.     

Electrochemical modeling of the reaction of 1-Chloro- and 1-Bromo-2,2,6,6-tetramethylpiperidine photolysis

Electrolysis of 1-Chloro- and 1-Bromo-2,2,6,6-tetramethylpiperidines yields free nitroxyl radical 2,2,6,6-tetramethylpiperidine-1-oxyl. The reaction mechanism is suggested, which is based on the intermediate formation of aminyl radical. Concurrently with the nitroxyl radical formation, electrochemical chlorination of 2,2,6,6-tetramethylpiperidine occurs. It is shown that the 2,2,6,6-tetramethylpiperidine can be used as a mediator in the electrochemical oxidation of alcohols.     

A kinetic study of the mechanism of esterification of 1-arylethanols in trifluoroacetic acid

Aryl substituent effects upon the rate constants for the esterification of a series of 1-arylethanols in trifluoroacetic acid are in accordance with a reverse A_AL1 mechanism, for which the Hammett reaction constant ? = ?3.69 has been determined by correlation with σ⁺ substituent constants. The rates of reaction are ca. 50-fold faster than those for corresponding benzyl alcohols which bear an electron-donating aryl substituent and which are also believed to undergo esterification in trifluoroacetic acid by the reverse A_AL1 mechanism; the reverse A_AC2 mechanism applies to benzyl alcohols which bear an electron- withdrawing aryl substituent.     

gem-Silylborylation of an sp carbon: novel synthesis of 1-boryl-1-silylallenes

[reaction: see text] Novel synthesis of 1-boryl-1-silylallenes involving gem-silylborylation of 3-chloro- or 3-alkoxyalkyn-1-yllithiums with (dimethylphenylsilyl)(pinacolato)borane has been established. The reaction proceeds via 1,2-migration of the silyl group from the negatively charged boron atom of an intermediary borate complex to the terminal acetylenic carbon and is accelerated by the addition of chlorotrimethylsilane in the case that methanesulfonyloxy is employed as a leaving group. Furthermore, axially enantioenriched products could be prepared from mesylates of optically active propargylic alcohols.     

Analytical utility of 2-halopyridinium salts,part III paper electrophoretic characterization of alcohols as 2-alkoxy-1-methylpyridinium p-toluenesulphonates

Summary A method using high-voltage paper electrophoresis to separate 2-alkoxy-l-methylpyridinium p-toluenesulphonates derived from alcohols is described. Various primary and secondary alcohols are characterized by the relative mobilities of the corresponding 2-alkoxyl-l-methylpyridinium cations using orthoboric acid-orthophosphoric acid-ethylene glycol buffer as electrolyte. The method proved to be useful for the detection and identification of alcohols present as impurities in solvents. A procedure is outlined that permits identification of the alkoxy groups of esters. The procedure utilizes the alkaline hydrolysis of esters, reaction of the alcohols so formed with 2-fluoro-1-methylpyridinium p-toluenesulphonate followed by electrophoresis of the derived 2-alkoxy-1-methylpyridinium p-toluenesulphonates. Nanomole quantities of the separated compounds have been made detectable on the pherograms using Dragendorff's reagent.Part II, Ref. [1]