Improved Syntheses of 5‐Hydroxy‐2‐Pyridones (2,5‐Dihydroxypyridines)

Improved syntheses of 5-hydroxy-2-pyridone, 6-chloro-5-hydroxy-2-pyridone, 2,5-dihydroxynicotinic acid, and three methyl-substituted 5-hydroxy-2-pyridones are reported.     

Practical Synthesis of N‐Alkyl‐N‐alkyloxycarbonylaminomethyl Prodrug Derivatives of Acetaminophen,Theophylline, and 6‐Mercaptopurine

We report a novel synthesis of N‐alkyl‐N‐alkyloxycarbonylaminomethyl (NANAOCAM) prodrugs of acetaminophen, theophylline, and 6‐mercaptopurine by alkylation of the corresponding drug molecule with N‐alkyl‐N‐alkyloxycarbonylaminomethyl chlorides in good yield. Most of the alkylating agents were efficiently synthesized by chloromethylation of N‐alkyl carbamic acid alkyl esters, which in turn were made from alkyl amines and alkyl chloroformates. In cases where the alkyl chloroformates were not available, synthesis of N‐alkyl carbamic acid alkyl esters was accomplished by converting an alcohol to a chloroformate or to an activated acylating agent such as acyl imidazoles or p‐nitrophenylcarbonate esters, followed by their reaction with alkyl amines.     

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.     

Improved Synthesis of N,N′‐Disuccinimidyl Carbonate using α‐Pinene as Acid Scavenger

An improved synthesis of N,N′‐disuccinimidyl carbonate (DSC) is described where α‐pinene is utilized as an efficient scavenger of HCl liberated during the reaction of N‐hydroxysuccinimide with triphosgene in THF. The α‐pinene hydrochloride formed is soluble in THF and gives very pure DSC in good yields.     

New and Improved Synthesis of Montelukast,an Anti‐asthmatic Drug

A new industrially viable synthesis of Montelukast, an anti‐asthmatic drug, is described.     

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.     

Interaction between Anionic and Zwitterionic Surfactants: Sodium Dodecyl Sulfate and N‐alkyl‐N,N‐dimethylsulfobetain,N‐lauroylsarcosine

The interaction between anionic and zwitterionic surfactant has been investigated through the measurements of surface tension and pH. These systems are sodium dodecyl sulfate (SDS) and N‐alkyl‐N,N‐dimethylsulfobetain(SB) N‐lauroylsarcosine(NL). As the molar ratio of SDS to SB is 7:3, the cmc of these systems exhibits minimum and the surface activity is in‐depend on pH. As the molar ratio of NL to SDS is from 3:7 to 7:3, the synergistic effect of the systems exhibits significantly, the surface tension increases with decreasing of pH and deposits has formed.     

Reaction of N‐Nonaflyl and N‐Cyano‐Benzotriazoles with Enamines

N‐Nonaflyl‐benzotriazole 1a reacts with enamines 2 in tetrahydrofurane (THF) at room temperature to afford o‐nonafluorobutansulfonamido‐phenylazo‐enamines 3 in 74–81% yield. Compound 1a reacts with 1‐diethylaminobutadien 2f twice, affording pyridazine derivative 3f in 20% yield. Ringopening of N‐cyano‐benzotriazole 1b with pyrrolidinocyclohexene 2a affords, under cleavage of pyrrolidine 1,2,3,4‐tetrahydro‐dibenzo[4,5:e]imidazo[1,2‐b][1,2,4]triazine 4 in 43% yield.     

Improved and Highly Versatile Synthesis of 5‐Aryltropones

Abstract

The use of 5‐iodo‐2‐methoxytropone in palladium(0)‐catalyzed coupling reactions with a variety of arylboronic acids has resulted in significantly improved reaction yields and times for a sterically and electronically diverse series of novel 5‐aryltropones. In addition, the required 5‐iodo‐2‐methoxytropone was conveniently synthesized in excellent yield.     

Convenient Syntheses of Daunomycinone‐7‐D‐Glucuronides and Doxorubicinone‐7‐D‐Glucuronides

Abstract

The first synthesis of new doxorubicin and daunomycin analogs containing glucuronic acid moieties instead of daunosamine are described. The desired products, daunomycinone‐7‐D‐glucuronide (DM7G, 10) and doxorubicinone‐7‐D‐glucuronide (DX7G, 11) were conveniently prepared through the glycosylation at 7‐hydroxyl group of daunomycinone (4) or 14‐acetoxydoxorubicinone (6) with glucuronic acid derivative 7 by the Koenigs‐Knorr procedure followed by alkaline deacetylation using aqueous LiOH solution and amberlite cation exchange material. The anomeric configuration and conformation of all products were fully characterized by assignment of ¹H NMR chemical shifts and H‐H coupling constants based on reported literatures.     

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.     

Superoxide‐Mediated Synthesis of N‐Aminoaziridines from N‐Aminoheterocycles and Olefins

Oxidation of 3‐amino‐2‐methyl‐4(3H)‐quinazolone and N‐aminophthalimide by superoxide ion generated in situ in the presence of olefinic substrates gives rise to the formation of N‐aminoaziridine derivatives.     

Molecular Dimension and Interaction Parameters of Polyacrylamide in Water‐N,N‐Dimethylformamide Mixtures

The intrinsic viscosities [η] of polyacrylamide (PAM) having different average molecular weights are measured in various mixtures of water (good solvent) and N, N dimethyl formamide (DMF, nonsolvent) at different temperatures. The observed results show a significant variation of cosolvency as a function of solvent composition (?_DMF). The nature of curves in [η] vs. ?_DMF plot at different temperatures indicates the existence of two antagonistic effects. The unperturbed dimensions (K_θ) of the polymer are determined by a number of methods, which agree well with each other. The temperature coefficient of unperturbed dimension (K′), molecular extension factors (α_n), characteristic ratio (C_α) and chain rigidity (σ) are evaluated and the effects of temperature, solvent composition are discussed. The volume related parameter V_E and shape factor ν were also computed, which shows the shape of polymer molecules to be more or less spherical in solution.     

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 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 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 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.     

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.