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.     

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.     

Alternative,High‐Yield Synthesis of (E)‐4‐Oxonon‐2‐enoic Acid from 2‐Methoxyfuran

Alkylation of 2‐methoxyfuran, followed by in situ TPP‐sensitized photooxygenation of 2‐methoxy‐5‐pentylfuran in the presence of Me₂S, gave methyl (Z)‐4‐oxonon‐2‐enoate. Hydrolysis of methyl (Z)‐4‐oxonon‐2‐enoate afforded (E)‐4‐oxonon‐2‐enoic acid in three steps and in 79% overall yield.     

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.     

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.     

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 4‐(CH₃)₂N, 4‐CH₃CO₂, 4‐CH₃CONH, 2‐CN, 3‐CN, 4‐CN, 4‐(C₂H₅)₂N) 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.     

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

Electrophilic trisubstituted ethylene monomers, alkoxy ring‐substituted 2‐cyano‐N,N‐dimethyl‐3‐phenyl‐2‐propenamides, RC₆H₄CH?C(CN)CON(CH₃)₂ (where R is 2‐OCH₃, 3‐OCH₃, 4‐OCH₃, 2‐OCH₂CH₃, 3‐OCH₂CH₃, 4‐OCH₂CH₂CH₃, 4‐OCH₂CH₂CH₂CH₃), 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, ACBN 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.     

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

Electrophilic trisubstituted ethylene monomers, halogen ring‐disubstituted 2‐cyano‐N,N‐dimethyl‐3‐phenyl‐2‐propenamides, RC₆H₃CH?C(CN)CON(CH₃)₂ (where R is 2,3‐dichloro, 2,4‐dichloro, 2,6‐dichloro, 3,4‐dichloro, 3,5‐dichloro, 2,3‐difluoro, 2,4‐difluoro, 2,6‐difluoro, 3,4‐difluoro, 3,5‐difluoro), 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.     

Synthesis of Anomerically Pure,Furanose‐Free α‐Benzyl‐2‐amino‐2‐deoxy‐d‐altro‐ and d‐manno‐pyranosides and Some of Their Derivatives

The anomerically pure benzyl α‐d‐glycoside of 2‐amino‐2‐deoxy‐mannopyranoside was synthesized from d‐glucopyranose via 2‐amino‐2‐deoxy‐d‐altrose intermediates. Unlike the direct synthesis from mannosamine in the literature, our method provides furanose‐free products. A new method for the preparation of cis‐2,3‐oxazolidinones of 2‐amino‐2‐deoxy‐sugars was developed. A selective removal of the glycosidic benzyl group in the presence of 4,6‐O‐benzylidene protection was developed, which may provide new routes for the synthesis of oligosaccharides. Furanose‐free derivatives of α‐benzyl‐2‐amino‐2‐deoxy‐mannopyranuronic acids synthesized here offered possibilities for direct comparisons to prior literature preparations.     

Novel Synthesis of Optically Active 2‐Ethylhexanoic Acid, 2‐Ethylhexanol,and 2‐Ethylhexylamine via the Asymmetric Favorskii Rearrangement

The asymmetric Favorskii rearrangement of optically active α‐haloketones, which are easily prepared from chiral menthyl‐4‐toluenesulfoxide in several steps using primary or secondary amines, yields their corresponding secondary or tertiary chiral amides. The secondary chiral amides were converted to acids or amines using acylation followed by hydrolysis or reduction. In addition, the tertiary amides were directly reduced to alcohol with Super‐Hydride^®.     

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.     

One‐Pot Synthesis of 2‐Arylthio‐2‐cyclohexenone Derivatives by the Diels–Alder Reaction of 4‐Arylthio‐3‐hydroxy‐2‐pyrones

The base‐catalyzed Diels–Alder reactions of 4‐arylthio‐3‐hydroxy‐2‐pyrones are reported. Treatment of 4‐arylthio‐3‐hydroxy‐2‐pyrones and dienophiles with triethylamine gave 2‐arylthio‐2‐cyclohexenone derivatives by the Diels–Alder reaction involving a decarboxylation in excellent to reasonable yields.     

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.     

Synthesis of Acylated Methyl 2‐Acetamido‐2‐Deoxy‐α‐D‐Mannopyranosides

Abstract

2‐Acetamido‐2‐deoxy‐β‐D‐mannopyranose (1) was glycosylated by the Fischer method using an acidic ion‐exchange resin as the catalyst to give α‐methyl glycoside 2. Selective pivaloylations of methyl 2‐acetamido‐2‐deoxy‐α‐D‐mannopyranoside (2) have been studied under various reaction conditions. Two partially pivaloylated products were submitted to additional acetylations. All structures were established by NMR spectroscopy. Structure of the methyl 2‐acetamido‐2‐deoxy‐3,6‐di‐O‐pivaloyl‐α‐D‐mannopyranoside (4) was determined by X‐ray analysis.     

Synthesis of Substituted 2‐Amino‐cyclobutanones

A series of weakly nucleophilic nitrogen derivatives including carbamates, amides, sulfonamides, and anilines were reacted with 1,2‐bis(trimethylsilyloxy)cyclobutene under acidic conditions to afford various substituted 2‐aminocyclobutanone derivatives 3a–i in modest to excellent yields.     

Convenient Method for Synthesis of Substituted 2‐Amino‐2‐chromenes

Some substituted 2‐amino‐2‐chromenes were synthesized by the reaction of arylidenemalononitriles with 1‐naphthol or 2‐naphthol in the presence of sodium hydroxide as catalyst under solvent‐free condition.     

An Efficient Synthesis of Derivatives of 2‐Acetamido‐4‐amino‐2,4,6‐trideoxy‐D‐galactopyranose

Abstract

Methyl 2‐acetamido‐4‐amino‐2,4,6‐trideoxy‐α‐D‐galactopyranoside (10) was synthesized from D‐glucosamine hydrochloride in eight steps in an overall yield of 31%. Key steps include the selective benzoylation at O‐3 of methyl 2‐acetamido‐2,6‐dideoxy‐α‐D‐glucopyranoside in 89% yield and the subsequent Mitsunobu reaction using diphenylphosphoryl azide as the azide source which proceeded in 92% yield. Di‐ and mono‐benzyloxycarbonyl derivatives of 10 were also prepared.     

Novel Copolymers of N‐(4‐Bromophenyl)‐2‐Methacrylamide with 2‐Acrylamido‐2‐Methyl‐1‐Propanesulfonic Acid

The new acrylamide monomer, N‐(4‐Bromophenyl)‐2‐methacrylamide (BrPMAAm) has been synthesized by reacting 4‐Bromoaniline with methacryloyl chloride in the presence of triethylamine(NR₃) at 0–5°C. The radical‐initiated copolymerization of (BrPMAAm), with 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid (AMPS) has been carried out in dimethylformamide (DMF) solution at 70±1°C using 2,2′‐azobisisobutyronitrile (AIBN) as an initiator with different monomer‐to‐monomer ratios in the feed. The copolymers were characterized by FTIR, ¹H‐ and ¹³C‐NMR spectroscopy. The copolymer composition was evaluated by nitrogen content (N for AMPS‐units) in polymers led to the determination of reactivity ratios. The monomer reactivity ratios for BrPMAAm (M₁)‐AMPS (M₂) pair were computed using the Fineman‐Ross (F‐R), Kelen‐Tüdös (KT) and Extended Kelen‐Tüdös (EKT) methods. These parameters were also estimated using a non‐linear computational fitting procedure, known as reactivity ratios error in variable model (RREVM). The mean sequence lengths determination indicated that the copolymer was statistically in nature. By TGA and DSC analyses, the thermal properties of the polymers have been studied. The antimicrobial effects of polymers were also tested on various bacteria, and yeast.