Living cationic polymerization of 2-chloroethyl vinyl ether: Kinetics,mechanism and application to polymer synthesis

The cationic polymerization of 2-chloroethyl vinyl ether initiated by HI/weak Lewis acid (I₂ or ZnI₂) systems has been studied from both a kinetic-mechanistic and a synthetic viewpoint. At low temperature and in toluene as solvent, the polymerization proceeds via a living process and the kinetic order with respect to monomer varies according to the nature of the Lewis acid activator. This behaviour can be explained by the coordination of the Lewis acid with both the monomer and the chain-end, the latter leading to a strong activation of the -I bond towards monomer insertion. The living polymerization obtained from divinylether precursors leads to -I ended telechelics, and their transformation into dihydroxytelechelic oligomers has been performed. The chemical modification of chloroalkyl side groups by phase transfer catalysis allows the attachment of specific groups without consumption of-OH ends.     

New fragmentation of 2‐isoxazoline‐5‐carboxylic acid chlorides

A novel base promoted degradation of 3‐aryl‐2‐isoxazoline‐5‐carboxylic acid chlorides to aryl nitriles has been discovered.     

Application on novel fragmentation reaction: A concise synthesis of 2,3,5‐trisubstituted furans from butenolides

Butenolides 4 , generated from a novel fragmentation reaction, function as excellent precursors to 2,3,5‐trisubstituted furans 5 by additions of alkyl or aryl metallic reagents. It can also be converted into siloxyfurans 6 by treatment with silylating reagents.     

1,8‐Diazafloren‐9‐one with alkyl and aryl isocyanides in the presence of acetylenic esters: A facile synthesis of γ‐spiroiminolactones

The 1:1 intermediate generated by the addition of alkyl and aryl isocyanides to dialkyl acetylenedicarboxylate is trapped by 1,8‐diazafloren‐9‐one to yield iminolactones in good yields.     

Darstellung neuer Spiro-Alkoxy-cyclophosphazatriene

Preparation of New Spiro-Alkoxy-Cyclophosphazatrienes New spiro-Alkoxy-cyclophosphazatrienes of the general formula are described. The preparation of the substances and their mass spectroscopic data are reported.     

One pot synthesis of diarylpyrido[3,2‐c]coumarins

Various diarylpyrido[3,2‐c]coumarins 3a‐l have been synthesized in one step by reacting 4‐hydroxy coumarins 1a‐d with α,β‐unsaturated ketones 2a‐c in the presence of ammonium acetate and acetic acid under Kroehnke's reaction conditions.     

Studies with 2‐arylhydrazononitriles: A novel simple,efficient route to 5‐acyl‐2‐substituted‐1,2,3‐triazol‐4‐amines

Efficient route to 5‐acyl‐2‐substituted‐1,2,3‐triazol‐4‐amines via reaction of 3‐oxo‐2‐(arylhydrazono)‐pentanenitrile with hydroxylamine hydrochloride is reported. X‐ray crystal structure has been made to confirm the structure of reaction products.     

New data about the reaction of benzyolacetonitrile with malononitrile and its self‐condensation

The reactions of benzoylacetonitrile with malononitrile in refluxing pyridine and its self condensation under fusion conditions in the presence of ammonium acetate and in refluxing pyridine were reinvestigated. New data were found and plausible mechanisms to account for the formation of the products are suggested.     

Highly diastereoselactive synthesis of chimeras of proline and glutamate

Azomethine ylides have been generated from aromatic aldimines of α‐amino acid methyl esters under treatment with LiBr/Et₃N and trapped with tert‐butyl acrylate yielding racemic orthogonally protected cis‐5‐arylpyrrolidine‐2,4‐dicarboxylates regio‐ and stereo‐selectively in high yields. Subsequent N‐methylation and deprotection of 4‐carboxylic group of cycloaddition products led to novel prolineglutamate cis‐chimeras with substituents at 2 and 5 positions of pyrrolidine scaffold.     

Zur Darstellung von Cyclophosphaten,Cyclophosphatophosphonaten, Diphosphonaten und Diphosphiten in Harnstoffschmelzen

Preparation of Cyclophosphates, Cyclophosphatophosphonates, Diphosphonates, and Di-phosphites in Urea Melts Ammonium cyclotriphosphate (NH₄)P₃O₉, ammonium cyclotetraphosphate [P^IV? P^IV ? O? ]₂, ammonium cyclotriphosphatophosphonates Ammonium organyldiphosphonates And ammonium diphosphites are prepared in high yields on heating acidic phosphates, phosphonates, and phosphites in urea or urea/ammonium nitrate melts. The mechanism of the dehydration of phosphorus compounds containing POH groups in molten urea is discussed.     

Regioselective synthesis of a new [1,2,3]‐triazoles directly from imidates

A one pot synthetic approach to the novel [1,2,3]‐triazoles system, by 1,3‐dipolar cycloaddition of 2‐diazopropane to the imidates 2 , is described. The structures of the obtained adducts have been assigned by means of spectroscopic measurements.     

Iodobenzene diacetate on alumina: Efficient synthesis of 1,3,4‐oxadiazolyl‐1,8‐naphthyridines in solventless system using microwaves

1‐(5‐Aryl‐[1,3,4]oxadiazol‐2‐ylmethyl)‐3‐(p‐methoxyphenyl)‐1H‐[1,8]naphthyridin‐2‐ones ( 5 ) were synthesized by the oxidative cyclization of [2‐oxo‐3‐(p‐methoxyphenyl)‐2H‐[1,8]naphthyridin‐1‐yl]acetic acid arylidene‐hydrazides ( 4 ) with alumina‐supported iodobenzene diacetate (IBD) in solvent‐free conditions under microwave irradiation. The products are obtained in good yields and in a state of high purity.     

Novel C‐acylated triazole derivatives of ravuconazole,an azole antifungal agent

Novel C‐acylated triazoles were synthesized from ravuconazole via bicyclic triazole lactone. The synthesis and antifungal activity of these C‐acylated derivatives are described.     

Aromatization of 1,4‐dihydropyridines in the presence of methanesulfonic acid/NaNO2/wet SiO2 under both heterogeneous and solvent free conditions

A combination of methanesulfonic acid and sodium nitrite in the presence of wet SiO₂ was used as an effective oxidizing agent for the oxidation of 1,4‐dihydropyridines to the corresponding pyridine derivatives under mild and heterogeneous conditions in excellent yields.     

Convenient synthesis of some new substituted pyrazolyl‐1,3,4‐oxadiazoles and pyrazolyl‐1,2,4‐triazoles

A simple and versatile method for the synthesis of pyrazol‐3‐yl‐1,3,4‐oxadiazole, pyrazol‐3‐yl‐1,2,4‐triazole, (1,5‐diphenylpyrazol‐3‐yl)‐(3,5‐dimethyl‐1‐carbonyl)pyrazole and (1,5‐diphenylpyrazol‐3‐yl)‐(5‐hydroxy‐3‐metheyl‐1‐carbonyl)pyrazole derivatives from 1,5‐diphenylpyrazole‐3‐carboxylic acid hydrazide has been developed.     

Convenient synthesis of N‐substituted 1‐alkyl and 1‐aryl‐3‐aminoisoquinolines

Cyclocondensation of 2‐acylphenylacetonitriles 1 with amines affords 1‐substituted 3‐aminoisoquinolines 2 in good yields.     

Thermal decomposition reactions of n‐alkylated 2‐aminobiphenyls to carbazole and phenanthridine

Thermal cyclization reactions were examined by passing vapors of N‐alkylated 2‐aminobiphenyls 1a‐c and 2 over calcium oxide at 450‐600°C under nitrogen carrier gas. The reactions yielded 9‐methylcarbazole 3 , carbazole 4 , phenanthridine 5 and phenanthrene 6. The major product for the reactions of 1a, 1b and 2 was phenanthridine 5 while that of 1c was carbazole 4.     

Synthesis of new terpolymers with heterocyclic pendant groups

Chemical modifications of polyacrylonitrile (PAN), an inexpensive and commercial homopolymer, to obtain terpolymers containing 1,2,4 or 1,3,4 oxadiazolic pendant groups are described. These new materials are physically and spectroscopically characterized.     

Synthesis and psychotropic properties of furyl- and thienyl-germatranes

Trihalogermyl-furans and -thiophenes were prepared by inserting germanium dibromide (GeBr₂) generated from the dibromogermane(II) dioxanate complex into the carbon-halogen bond of halo-furans and -thiophenes. Their ethanolysis and transesterification by triethanolamine yielded the germatranes which were subjected to psychotropic activity assays. The psychotropic properties of germatranes were found to depend on the type of the heterocycle and on the position of the germatrane moiety.