Synthesis and characterization of 4‐aryl‐5‐(1‐aryl‐2‐methyl‐2‐nitropropyl)‐1,2,3‐selenadiazoles

The synthesis of a new set of selenadiazoles, 4‐aryl‐5‐(1‐aryl‐2‐methyl‐2‐nitropropyl)‐1,2,3‐selenadiazoles ( 4 ) derived from 2‐[4‐methyl‐4‐nitro‐1,3‐diarylpentylidene]‐1‐hydrazinecarboxamide ( 3 ) has been reported. THF has been found to be the solvent of choice for this reaction. Structural features of 3 and 4 have been analyzed by NMR and X‐ray techniques.     

Cyclocondensation reactions of heterocyclic carbonyl compounds XII. The double course of cyclization of 3‐(2‐aminobenzyl)‐1,2‐dihydro‐quinoxaline‐2‐one

The cyclocondensation reaction of compound 1 in boiling hydrochloric acid had an unexpected course. Instead of supposed 5,11‐dihydro‐quinoxalino[2,3‐b]quinoline 6a , 2‐(indol‐2‐yl)‐benzimidazole 4 was isolated as the major product.     

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.     

Synthesis of 2‐phenylquinolin‐4‐amines substituted with diverse amino and aminoalkyl groups

Facile synthetic approaches to 2‐phenylquinolin‐4‐amines containing an aminoalkyl group at N⁴ of the quinolin‐4‐amine and amino or aminoalkyl groups at the phenyl moiety are presented.     

An efficient one‐pot synthesis of polyhydrobenzoacridine‐1‐one derivatives under microwave irradiation without catalyst

A series of 3,3‐dimethyl‐9‐substituted‐1,2,3,4,9,10‐hexahydrobenzo[c] acridine‐1‐ones and 3,3‐dimethyl‐9‐substituted‐1,2,3,4,9,10‐hexahydrobenzo[a] acridine‐1‐ones were synthesized by the reaction of an aldehyde, α‐naphthylamine or β‐naphthylamine and dimedone under microwave irradiation with short times and high 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.     

Synthesis of some new 4‐substituted‐3, 5‐bis(2‐pyridyl)‐1h‐pyrazole

Several 4‐substituted‐3, 5‐bis(2‐pyridyl)‐1H‐pyrazoles, where the substituent is chloro, bromo, iodo, nitro, diazo, were synthesized under mild reaction conditions in high yields. The structures of the products were characterized by ¹H NMR, ¹³C NMR, ESI‐MS, IR and elemental analyses.     

Synthesis of novel substituted flavonoids

Eighteen substituted chalcones, flavones and 3‐flavonols were synthesized and characterized using ¹H‐NMR, IR and elemental analysis. The substitution pattern includes two halogen atoms, nitro and methyl groups in ring A as well as two or three methoxy groups in ring B.     

Synthesis and physicochemical properties of new 1N o‐(m‐ and p‐) bromobenzyl substituted derivatives of 5‐(aminodialkyl)methylcytosine

Simple alkylation of 5‐(aminodialkyl)methylcytosine a‐d gives twelve new, potentially biologically active 1N o‐(m‐ or p‐) bromobenzyl derivatives of 5‐substituted cytosine 1‐12 with high regioselectivity. The structures of all compounds have been confirmed by elemental analysis, IR, ¹H NMR and ¹³C NMR spectroscopic measurements.     

Initiation Kinetics in Free‐Radical Polymerization: Prediction of Thermodynamic and Kinetic Parameters Based on ab initio Calculations

Initiation kinetics in free radical polymerization is investigated using density functional theory. Thermodynamic and kinetic parameters of the initiation reactions are predicted, and the role of the initiators in the polymerization process is evaluated. Methyl acrylate, methyl methacrylate, acrylonitrile, and styrene homo‐polymerizations with different initiators are studied. Reaction enthalpy and activation energy for each reaction between monomer and the radical fragments arising from the initiators have been determined. The initiation kinetic constants for all of these initiation reactions are evaluated and compared with both computational and experimental propagation kinetic constants of each monomer.

     

An improved synthesis of 1‐acetyl‐1H‐indol‐3‐yl acetates

An efficient two steps procedure for the synthesis of 1‐acetyl‐1H‐indol‐3‐yl acetates, starting from 2‐chlorobenzoic acids, was developed and in general, moderate to good yields were obtained     

Structure determination of N‐methyl‐tetrahydro‐5H‐indazol‐5‐ones

This paper communicates the (regio) synthesis and a convenient NMR structural assignment method for N‐methyl‐tetrahydro‐5H‐indazol‐5‐one isomers. The cyclization reaction of 7‐(hydroxymethylene)‐1,4‐dioxaspiro[4,5]decan‐8‐one ( 3 ) with methylhydrazine yields, after de‐protection predominately the N‐2 methyl isomer 2 . Analysis of the product ratio and structural assignments are based on NMR data including NOE difference experiments and subsequently confirmed with X‐ray crystallography. These findings are in sharp contrast with the literature. The experimental conditions used to optimize the synthesis of the individual isomers are discussed.     

Synthesis of aryltrifluoromethylpyridazines application to the synthesis of rod‐like molecules as liquid crystals diazines part 46

Conjugated oligomers with a trifluoromethylpyridazine unit have been synthesized by Suzuki crosscoupling reaction. These oligomers could be used as building block for construction of supramolecules or as liquid crystals when they are substituted by long chain alkoxy groups.     

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.     

Facile synthesis of pyrrolo[2,1‐c][1,4]benzodiazepine‐5,11‐dione dimer

Efficient synthesis of biological important pyrrolo[2,1‐c][1,4]benzodiazepine‐5,11‐dione dimer linked through the C‐2 positions by fumarate group is described.     

Synthesis,structure and biological activities of [α‐(alkylcarbonyl)‐2‐(1,2,4‐triazol‐1‐yl)]ethyl‐N,N‐dialkydithiocarbamate derivatives

Seven 1,2,4‐triazole compounds containing the N,N‐dialkyldithiocarbamate group were designed and synthesized. Their structures were identified using infrared spectroscopy, element analysis, ¹H NMR spectroscopy and mass spectrometry, and in two cases by single crystal X‐ray diffraction. The result of the biological test showed that the seven compounds all have fungicidal and plant growth‐regulating activities.     

Ring expansion of isopropenyldihydrofuran derivatives

Lactonization of 2‐(hydroxymethyl)‐5‐isopropenyl‐4,5‐dihydrofuran‐3‐carboxylic acids 1a,b,c with dicyclohexylcarbodiimide gave the corresponding furano‐lactones, 5‐isopropenyl‐5,6‐dihydro‐1(3H)‐furo[3,4‐b]furanone 2a,b,c , which were readily converted to the corresponding oxepino‐lactones, 6‐methyl‐5,8‐dihydro‐1(3H)‐furo[3,4‐b]oxepinone 3a,b,c by respective thermal ring expansions.     

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.     

Reactions of cephalosporin sulfones 3. Synthesis of 2‐phenylhydrazonocephem‐sulfones. A new potential entry to 2‐aminocephems

Reaction of cephem sulfones 1a‐e with aryldiazonium salts gives the 2‐azo compounds which immediately rearrange into the corresponding 2‐hydrazono derivatives 2a‐e .     

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.