Formation of 1,2,5‐Oxadiazole,Isoxazole, Isothiazole, 1,2,3‐Triazole,and Pyrrole Rings from N‐(5,5‐Dimethyl‐3‐oxocyclohexenyl)‐S,S‐diphenylsulfilimine

Reactions of N‐(5,5‐dimethyl‐3‐oxocyclohexenyl)‐S,S‐diphenylsulfilimine, a kind of enaminone, with isopentyl nitrite, isocyanates, isothocyanates, benzenediazonium chloride, and 1,1,1‐trifluoro‐4‐ethoxy‐3‐buten‐2‐one gave 1,2,5‐oxadiazole, isoxazole, isothiazole, 1,2,3‐triazole, and pyrrole derivatives condensed with cyclohexane, respectively, in one pot.     

Synthesis of 1,2,4‐Triazinediones, 1,2,4,3‐Triazaphospholines,and 1,2,4,3‐Triazaphospholine‐3‐oxide Derivatives

The reaction of N ¹‐tosylamidrazones 1 with oxalyl dichloride, phosphorus trichloride, and phosphoryl chloride leads to 1,2,4‐triazinediones 3 , 1,2,4,3‐triazaphospholines 4 , and 1,2,4,3‐triazaphospholine‐3‐oxides 5 , respectively. The structures of the new products have been established by IR; ¹H, ¹³C, and ³¹P NMR studies; and elemental analysis.     

Comparative Analysis of the Properties of Tween‐20, Tween‐60, Tween‐80, Arlacel‐60, and Arlacel‐80

Foamability and foam stability, emulsifying power, surface tension, and interfacial tension were investigated for Tween‐20 (polyoxyethylene sorbitan monolaurate), Tween‐60 (polyoxyethylene sorbitan monostearate), Tween‐80 (polyoxyethylene sorbitan monooleate), Arlacel‐60 (Sorbitan stearate), and Arlacel‐80 (Sorbitan oleate). Among all the surfactants tested for their foaming power and foamabilty, Arlacel‐60 and Arlacel‐80 showed the best results; the foaming power and foamability was found to be 100%. The surfactants having foam stability more than 50% can be considered as metastable and those less than 50% are considered as low‐stability foams. In case of surface tension and interfacial tension property measurements, Arlacel‐80 showed the best results. At 1% surfactant concentration, the surface tension and interfacial tension of Arlacel‐80 was found to be 29.9 dynes/cm and 1.1 dynes/cm at 30°C ambient temperature. Also, Arlacel‐60 was found to exhibit the best emulsifying power among all the surfactants tested. At 30°C, the emulsifying property of Arlacel‐60 was 6 hours.     

Microwave‐Accelerated,Three‐Component,One‐Step Synthesis of 2‐Acylimino‐3‐aryl‐3H‐thiazolines under Solvent‐Free Conditions

2‐Acylimino‐3‐aryl‐3H‐thiazoline derivatives could be generated in excellent yields through three‐component condensations of aroylisothiocyanates, primary amines, and ω‐haloacetophenone under solvent‐free microwave irradiation.     

Synthesis,Structures, and Properties of Novel N‐Aryl‐phenanthren‐o‐iminoquinones

The interaction of 9,10‐phenanthrenquinone with primary amines has been studied. Use of sterically hindered anilines gave the phenanthren‐o‐iminoquinones in good yields. These compounds are structural analogues of o‐benzoquinones. Using single‐electron reduction, o‐iminoquinones may synthesize metal's free‐radical complexes.     

Simple,Efficient, and Stereoselective Oxidation of Triphenylfurans to cis‐But‐2‐ene‐1,4‐diones

Triphenylfurans are stereoselctively oxidized to cis‐but‐2‐ene‐1,4‐diones, suitable precursors of 3(2H)‐furanones, in very good yields using ammonium nitrate or potassium nitrate in 80% aqueous acetic acid.     

From Tri‐O‐Acetyl‐D‐Glucal to (2R,3R,5R)‐2,3‐Diazido‐5‐Hydroxycyclohexanone Oxime

Abstract

Methyl 3‐azido‐2,3‐dideoxy‐α/β‐D‐arabino‐ and ‐α/β‐D‐ribo‐hexopyranosides were transformed into 6‐iodo analogues via p‐tolylsulfonyl compounds. Elimination of hydrogen iodide from 6‐iodo glycosides provided methyl 4‐O‐acetyl‐3‐azido‐2,3,6‐trideoxy‐α‐ and ‐β‐D‐threo‐hex‐5‐eno‐pyranosides or 3‐azido‐4‐O‐p‐tolylsulfonyl‐2,3,6‐trideoxy‐α‐D‐threo‐ and ‐β‐D‐erythro‐hex‐5‐eno‐pyranosides. Ferrier's carbocyclization of 4‐O‐acetyl‐3‐azido‐2,3,6‐trideoxy‐α‐ and ‐β‐D‐threo‐hex‐5‐eno‐pyranosides gave (2S,3R,5R)‐2‐acetoxy‐3‐azido‐5‐hydroxycyclohexanone, which was converted into oxime. The 2‐OAc group in oxime was substituted by azide ion to yield (2R,3R,5R)‐2,3‐diazido‐5‐hydroxycyclohexanone oxime. The configuration and conformation of all products are widely discussed on the basis of the ¹H and ¹³C NMR.     

Iodine‐Mediated Synthesis of 2‐Arylbenzoxazoles, 2‐Arylbenzimidazoles,and 1,3,5‐Trisubstituted Pyrazoles

2‐Arylbenzoxazoles and 2‐arylbenzimidazoles were synthesized by the reaction of aldehydes with 2‐aminophenol and O‐phenylenediamines in the presence of iodine. 1,3,5‐Trisubstituted pyrazoles were synthesized from chalcones and hydrazines in the presence of iodine.     

Iodine‐Catalyzed,One‐Pot,Solid‐Phase Synthesis of Benzothiazole Derivatives

Molecular iodine was utilized in a one‐pot, solid‐phase, solvent‐free reaction between 2‐aminothiophenol and benzoic acid derivatives to obtain highly economical and excellent yield of benzothiazole derivatives in comparison to polyphosphoric acid- and [pmIm]‐Br‐catalyzed microwave synthesis reactions. The results of the studies revealed that the new method reduces cost by approximately 17‐fold in comparison to polyphosphoric acid and has a significant cost reduction in comparison to [pmIm]‐Br. Moreover, it becomes even more economical because no additional chemicals and solvents are necessary for the reaction.     

Convenient Preparation of N,N′‐Diphenyl‐N,N′‐bis(4‐aminophenyl)‐p‐phenylenediamine

Abstract

This article describes modified conditions to prepare N,N′‐diphenyl‐N,N′‐bis(4‐aminophenyl)‐P‐phenylenediamine in 60% overall yield.     

MAOS of D‐Gluconic Acid,D‐Glucono‐1,4‐ and 1,5‐Lactones,Esters, Hydrazides,and Benzimidazoles Thereof

Microwave‐assisted organic synthesis (MAOS) of D‐gluconic acid can be efficiently done by oxidation of D‐glucose with bromine water, upon irradiation with microwave (MW). It was also used for the conversion of D‐gluconic acid to ethyl D‐gluconate, D‐glucono‐1,4‐ and 1,5‐lactones, gluconyl hydrazide, and gluconyl phenylhydrazide in yields comparable to those obtained by conventional methods, but in much shorter times. A convenient microwave‐mediated condensation of D‐gluconic acid with o‐phenylenediamines provided the respective acyclonucleoside benzimidazole in short time and good yield.      

Synthesis and Amphiphilic Behavior of N,N‐Bis‐glucosyl‐1,5‐benzodiazepin‐2,4‐dione

Abstract

Glucosyl‐1,5‐benzodiazepin‐2,4‐diones were synthesized in order to study the influence of the glucidic moiety on the amphiphilic behaviour. The glucosyl groups include 6‐deoxy‐D‐glucopyranos‐6‐yl and 6‐deoxy‐3‐O‐R‐D‐glucopyranos‐6‐yl (R = n ? C _n H _2n+1; n = 1, 8, 10 and 12). Variation in the length of the hydrocarbon chain allowed comparison of such amphiphilic data as water solubility (Sw) and surface tension (γ) values. At 25°C, the glucopyranosyl benzodiazepines with R = H and CH₃ show a higher water solubility than the starting 1,5‐benzodiazepin‐2,4‐diones. Some other glucidic benzodiazepine derivatives with an appropriate alkyl chain at C‐3 carbon of the D‐glucopyranose present a variable hydrosolubility and surface tension γ values close to 43 to 46 mN · m^?1 at the corresponding saturation. Moreover, according to preliminary tests, these compounds seem to show a better affinity for the blood brain barrier.     

N‐Chlorosulfonyloxazolidin‐2‐ones: Synthesis,Structure, and Reactivity Toward Aminoesters

Abstract

Synthesis, structure, and reactivity of chiral N‐chlorosulfonyloxazolidin‐2‐ones are described. Their synthesis were easily carried out starting from the corresponding chiral oxazolidin‐2‐ones and sulfuryl chloride to afford the title compounds 1 in high yields.     

Facile Method for Stereoselective Synthesis of New Chiral (1R,4aR,8aR)‐1,3,4,4a,5,7,8,8a‐Octahydro‐2‐methylene‐naphthalene‐6‐one‐1‐propanenitrile,an Important Precursor of Solanapyrones

A novel and facile strategy for stereoselective synthesis of new chiral (1R,4aR,8aR)‐1,3,4,4a,5,7,8,8a‐octahydro‐2‐methylenenaphthalene‐6‐one‐1‐propanenitrile (8) by one‐pot stereoselective hydrogenation/acetalization and Beckmann fragmentation is described. Chiral octalone 8, an important precursor of solanapyrone, was obtained in good yield.     

Synthesis of Novel (3a,S)‐1‐Aryl/aryloxy/alkoxy‐3a,4‐dihydro‐3H‐1λ5‐[1,3,2]oxazaphospholo [3,4‐a] indole‐1‐ones,Thiones, and Selenones

Synthesis of novel (3a,S)‐1‐aryl/aryloxy/alkoxy‐3a,4‐dihydro‐3H‐1λ⁵‐[1,3,2]oxazaphospholo [3,4‐a] indole‐1‐ones, thiones, and selenones was achieved in two steps with high yields from 2,3‐dihydro‐1H‐indol‐2(S)yl methanol (1) and dichlorophenyl phosphine/ethyl dichlorophosphite (2a and b) in the presence of triethylamine in dry THF followed by treatment with hydrogen peroxide, sulfur, and selenium. The compounds 4g–k have been synthesized by the direct cyclocondensation of 1 with different substituted phenyl phosphorodichloridates (2c–e, g) and bis(2‐chloroethyl) phosphoramidic dichloride (2f).     

Novel Copolymers of Styrene and Some Ring‐Substituted 2‐Cyano‐N,N‐Dimethyl‐3‐Phenyl‐2‐Propenamides

Electrophilic trisubstituted ethylene monomers, ring‐substituted 2‐cyano‐N,N‐dimethyl‐3‐phenyl‐2‐propenamides, RC₆H₄CH?C(CN)CON(CH₃)₂ (where R is 3‐benzyloxy, 4‐benzyloxy, 3‐ethoxy‐4‐methoxy, 3‐bromo‐4‐methoxy, 5‐bromo‐2‐methoxy, 2‐chloro‐6‐fluoro) were synthesized by potassium hydroxide catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and N,N‐dimethyl cyanoacetamide, and characterized by CHN elemental analysis, IR, ¹H‐ and ¹³C‐NMR. Novel copolymers of the ethylenes and styrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator, ABCN at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, ¹H and ¹³C NMR, GPC, DSC, and TGA. High T_g of the copolymers in comparison with that of polystyrene indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 300–450°C range.     

Preparation of Building Blocks for Carba‐Oligosaccharides: Some Protected 5a′‐Carba‐D‐hexopyranosyl‐1,5‐anhydro‐2‐deoxy‐D‐arabino‐hex‐1‐enitols,and 5a,5a′‐Dicarba Congeners Thereof

Four configurational types of two protected O‐linked (5a‐carba‐D‐hexopyranosyl)‐D‐glucal and carba‐D‐glucal derivatives were prepared in order to provide versatile synthetic intermediates readily convertible into carba‐oligosaccharides of biological interest. These compounds may also find application as donors for elongation of carba‐oligosaccharide chains having O‐linked carbahexopyranose residues at nonreducing ends.     

Novel Copolymers of Styrene and Halogen Ring‐Substituted 2‐Cyano‐N,N‐Dimethyl‐3‐Phenyl‐2‐Propenamides

Electrophilic trisubstituted ethylene monomers, halogen ring‐substituted 2‐cyano‐N,N‐dimethyl‐3‐phenyl‐2‐propenamides, RC₆H₄CH [dbnd]C(CN)CON(CH₃)₂ (where R is 2‐Br, 3‐Br, 4‐Br, 2‐Cl, 3‐Cl, 4‐Cl, 2‐F, 3‐F, 4‐F), were synthesized by potassium hydroxide catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and N,N‐dimethyl cyanoacetamide, and characterized by CHN elemental analysis, IR, ¹H‐ and ¹³C‐NMR. Novel copolymers of the ethylenes and styrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator, ABCN at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, ¹H and ¹³C NMR, GPC, DSC, and TGA. High T _g of the copolymers in comparison with that of polystyrene indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 300–450°C range.     

Suzuki Coupling of 2‐Chloroacrylonitrile,Methyl 2‐Chloroacrylate,or 2‐Chloroprop‐1‐en‐3‐ol with Arylboronic Acids Catalyzed by a Palladium‐Tetraphosphine Complex

The tetraphosphine all‐cis‐1,2,3,4‐tetrakis(diphenylphosphinomethyl)cyclopentane (Tedicyp) in combination with [Pd(C₃H₅)Cl]₂ affords an efficient catalyst of the coupling of 2‐chloroacrylonitrile with arylboronic acids. In the presence of 1% catalyst, the 2‐arylacrylonitrile derivatives were obtained in medium to good yields. A variety of substituents such as alkyl, methoxy, fluoro, trifluoromethyl, formyl, or nitro on the arylboronic acid are tolerated. The cross‐coupling reactions of methyl 2‐chloroacrylate with arylboronic acids give simple access to 2‐phenylacrylate derivatives, which are useful precursors for the synthesis of biologically active compounds such as ibuprofen, ketoprofen, and naproxen.     

Copolymers of 2‐(3‐(6‐tetralino)‐3‐methyl‐1‐cyclobutyl)‐2‐Hydroxyethyl Methacrylate with Acrylonitrile and 4‐Vinylpyridine: Synthesis,Characterization, and Monomer Reactivity Ratios

The copolymerization of 2‐(3‐(6‐tetralino)‐3‐methyl‐1‐cyclobutyl)‐2‐hydroxyethyl methacrylate (TCHEMA), monomer with acrylonitrile and 4‐vinylpyridine were carried out in 1,4‐dioxane solution at 65°C using AIBN as an initiator. The copolymers were characterized by FTIR, ¹H‐NMR, and ¹³C‐NMR spectroscopic techniques. Thermal properties of the polymers were also studied by thermogravimetric analysis and differential scanning calorimetry. The copolymer compositions were determined by elemental analysis. The monomer reactivity ratios were calculated by the Fineman‐Ross and Kelen‐Tüdös method. Also, the apparent thermal decomposition activation energies were calculated by the Ozawa method with a Shimadzu TGA 50 thermogravimetric analysis thermobalance.