Synthesis and Properties of Polyamides of 2,2′-[Isopropylidenebis-(p-phenyleneoxy)] diacetic Acid

A group of six semiaromatic polyamides of 2,2′-[isopropylidenebis-(p-phenyleneoxy)]diacetic acid (Bisacid A₂) were synthesized by low-temperature solution polycondensation techniques. Six different diamines were condensed independently with Bisacid A₂ chloride in a mixture of N-methylpyrrolidone (NMP and hexamethylhosphoramide (HMPA). The polymers were obtained in 82–95% yield and possessed inherent viscosities in the range from 0.32 to 0.63 dL/g. The polyamides were characterized by IR and 'H-NMR spectra. The molecular weight and molecular weight distribution of the polyamides were determined by gel-permeation chromatography. The thermal stability, thermal degradation kinetics, crystallinity, density, and solubility were also determined. A model diamide (MDA) was synthesized from aniline and Bisacid A₂ chloride to confirm the formation of polyamides from diamines.     

Synthesis and Characterization of N-(2,2-Diphenylacetyl)- N′-Substituted Thiourea Derivatives: The Crystal Structure of N-(2,2-Diphenylacetyl)-N′-(4-chloro phenyl)-thiourea

A series of new N-(2,2-diphenylacetyl)-N ′-substituted thiourea derivatives (1–9) have been prepared and characterized by elemental analyses, IR and ¹H NMR spectroscopy. N-(2,2-diphenylacetyl)-N ′-(4-chlorophenyl)-thiourea was also characterized by a single crystal X-ray diffraction study. The compound crystallizes in the monoclinic space group P2₁/c with Z = 4 and a = 9.6551(19) Å, b = 20.060(4) Å, c = 9.894(2) Å, β = 104.29(3)°. The molecular conformation of the compound is stabilized by an intramolecular (N1-H1···O1) hydrogen bond that forms a pseudo-six-membered ring.     

Synthesis and Properties of Cobalt(II) Tetrakis-[4,5-di(4′-carboxy)phenylene(oxy/sulfanyl/amino)]phthalocyanines

Russian Journal of General Chemistry - Phthalonitriles with fragments of 4-hydroxy, 4-mercapto and 4-aminobenzoic acids were synthesized by nucleophilic substitution in...     

Synthesis and Luminescence Spectral Properties of New Cyano-Substituted 2,2′-Bipyridine Derivatives

Russian Journal of Organic Chemistry - Previously unknown 2-{4-aryl-5-cyano-[2,2′-bipyridin]-6(1H)-ylidene}malononitriles were synthe­sized by reaction of...     

Synthesis and applications of (R)- and (S)-7,7′-dimethoxy-2,2′-bis(diphenylphosphino)-1,1′-binaphthalene

The synthesis of (R)- and (S)-7,7′-dimethoxy-2,2′-bis(diphenylphosphino)-1,1′-binaphthalene 5a and 5b is described. The phosphorus atoms in (S)-(−)-5b are shown to be slightly more basic than the phosphorus atoms in (S)-BINAP by comparing the magnitude of the ¹J (³¹P–⁷⁷Se) coupling constant in their respective diselenide derivatives. (S)-(−)-5b behaved similarly to (S)-BINAP in asymmetric Heck reactions.     

Synthesis of some new Spiro(Pyran-4,2′- Oxazolidine) and Pyridoxazolidine Derivatives

Ketene S,S-acetal 2 reacts with aminoethanol to afford 2-(1-acetal -2-oxo propylldine)oxazolldine 3 which was allowed to react with some active methylene compounds having an α- cyano or α-keto group to give spiro(pyran -4,2′-oxazolldine) derivatives 6-11. Compound 3 reacted with some α, β -unsaturated nltriles to afford the corresponding pyrldoxazolldine derivatives 12a-h through a nucleophillc addition and cyclization.     

Synthesis and Chiroptical Properties of Poly[N-(4-N′-(α-Methylbenzyl)-Aminocarbonylphenyl)-Mamaleimide]

Abstract

Radical homopolymerization of N-[4-N′-(α-methylbenzyl)-aminocarbonylphenyl]maleimide ((S)-MBCP) was carried out at 50 and 70°C for 24 h to give optically active polymers ([α]²⁵ _D = 159.8 to 163.4°). Radical copolymerizations of (S)-MBCP (M₁) were performed with styrene (ST, M₂, methyl methacrylate (MMA, M²) in THF at 50°C. The monomer reactivity ratios (r ₁, r ₂) and the Alfrey-Price Q, e values were determined as follows: r ₁ = 0.32, r ₂= 0.14, Q ₁ = 1.74, e ₁ = 0.96 in the (S)-MBCP-ST system; r ₁ = 0.54, r ₂ = 0.93, Q ₁ = 1.11, e ₁ = 1.23 in the (S)-MBCP-MMA system. Chiroptical properties of the polymers and the copolymers were also investigated, and asymmetric induction into the copolymer main chain is discussed.     

Synthesis and Crystal Structure of Bis-{N-[2-(6-ethylpyridyl)]-salicylideneiminato} Cobalt(Ⅱ)

The title complex 1, C28H26CoN4O2, crystallizes in the triclinic system, space group P-1 with a = 9.506(3), b = 9.506(3), c = 14.837(5) A, α = 106.397(5), β = 106.012(5), γ =91.889(6)°, V = 1217.7(7) A3, Z = 2, Dc=1.390 g/cm3, Mr= 509.46, F(000) = 530,μ(MoKα) =0.738 mm-1, the final R = 0.0359 and wR = 0.0951 for 4275 observed reflections with I ＞ 2σ(I).The complex adopts a distorted tetrahedral coordination sphere around the cobalt atom.     

PPA-SiO2 Catalyzed Multi-component Synthesis of N-[α-(β-Hydroxy-α-naphthyl)(benzyl)] O-Alkyl Carbamate Derivatives

Silica-supported polyphosphoric acid (PPA-SiO2) was found to be an efficient catalyst for the multi-component condensation reaction of benzaldehydes, 2-naphthol, and methyl/benzyl carbamate to afford the corresponding N-[α-(β-hydroxy-α-naphthyl)(benzyl)] O-alkyl carbamate derivatives in good to excellent yields. This new approach consistently has the advantage of short reaction time, high conversions, clean reaction profiles, and simple experimental and work-up procedures.     

Synthesis and Crystal Structure of Bis-{N-[2-(6-ethylpyridyl)]-salicylideneiminato} Cobalt(Ⅱ)

1 INTRODUCTION The Schiff bases derived from salicylaldehyde and 2-aminopyridine derivatives have been used as potentially terdentate ligands[1]. Yamada and Yam- anouchi have synthesized the type of ML2nH2O complexes (M = CoⅡ, NiⅡ, CuⅡ, ZnⅡ or PdⅡ)[     

Preparation and Characterization of 2,2′-Dipicolyl Diselenide and Their Derivatives

Lithium 2-picolylselenolate/tellurolate is obtained by reacting lithiated 2-picoline with elemental selenium/tellurium which upon aerial oxidation gives 2,2'-dipicolyl diselenide in case of selenium while 1,2-bis(2-pyridyl)ethane in case of tellurium. Condensation of 2-picolylselenolate anion with a variety of electrophiles provides a facile synthesis of 2-picolylalkyl selenides in good to excellent yields. Quenching of lithiated 2-picoline with 2,2'-dipyridyl diselenide gives mixed 2-picolylseleno pyridine in low yield. All the compounds prepared are new and have been characterized by elemental analysis, 1 H NMR, 13 C NMR and mass spectral studies.     

Synthesis and structure of 2,2′-diaminodiphenylditelluride bis-imines

Bis-imines of 2,2′-diaminodiphenylditelluride and 2-tosylamino (9a) and 2-hydroxybenzaldehyde (9b) were prepared and studied by X-ray diffraction, heteronuclear (¹H, ¹³C, ¹⁵N, and ¹²⁵Te) magnetic resonance, and quantum chemical calculations (Pbe1pbe/DGDZVP). According to the X-ray diffraction data, compound 9b in the crystal phase has nonsymmetrical structure: one of the tellurium atoms forms hypervalent bonding with the adjacent oxygen atom, while the second one is not involved in such interaction. The NMR study showed the symmetric molecular structure of imines 9a,b in DMSO-d₆ with the tellurium atoms interacting hypervalently with the C=N nitrogen atoms.     

Synthesis,resolution and application of 2,2′-bis(di-2-furylphosphino)-1,1′-binaphthalene

A six step synthesis and resolution of (±)-2,2′-bis(di-2-furylphosphino)-1,1′-binaphthalene 4 (TetFuBINAP) is described along with its use in asymmetric inter- and intramolecular Heck reactions.     

Synthesis of poly(2,2′,3,3′-indole)

New approaches to the synthesis of poly(2,2′,3,3′-indole) were developed based on the photochemical dehydropolycondensation of indole in the presence of iodine and the photochemical polycondensation of 1-(1H-indol-3-yl)-2-iodo-1-ethanone in the absence of catalyst and solvent. A suggested mechanism for the formation of the oligomeric chain in these reactions includes the intermediate formation of 3,3′-diindole with subsequent polycondensation via elimination of hydrogen atoms at position 2 of the dimer pyrrole fragment.     

Synthesis and structural investigation of 4,4′-dimethyl-[3,3′-bi(1,2,5-oxadiazole)] 5,5′-dioxide

The oxidation of hexane-2,3,4,5-tetraone tetraoxime with dinitrogen tetroxide was studied in different solvents. The primary furoxan ring closure was found to occur involving either two central or two terminal oxime groups to form 4,7-dimethyl[1,2,5]oxadiazolo[3,4-d]pyridazine 1,5,6-trioxide and the previously unknown 4,4′-dimethyl-[3,3′-bi(1,2,5-oxadiazole)] 5,5′-dioxide. The structure of the latter compound was established by X-ray diffraction.     

A Large-Scale Synthesis of Spiro [Cyclopropane-1,9′- [9H] Fluorene] and Derivatives

Our studies of the conjugative properties of cyclopropanes required the synthesis of large quantities of spiro [cyclopropane-1,9′- [9H] fluorene] (1) and its derivatives.¹ The method of Corey² is suited for the preparation of modest (1–5 g) amounts of 1 in one step. This procedure has failed to produce the desired cyclopropane when applied to substituted fluorenones.³     

Synthesis and Crystal Structure of [Zn(FcCOO)2(2,2′-bipy)(H2O)]2·H2O

A novel complex [Zn(FcCOO)2(2,2′-bipy)(H2O)]2·H2O (Fc = (η5-C5H5)Fe(η5-C5H4), 2,2′-bipy = 2,2′-bipyridine) has been synthesized and characterized by elemental analysis, IR and X-ray diffraction. It crystallizes in monoclinic system, space group P21/c with a = 6.8187(4), b = 21.7155(13), c = 19.7411(12) (A), α = 90, β = 97.7420(10), γ = 90°, C64H58Fe4Zn2N4O11, Mr = 1413.28, V = 2896.4(3) (A)3, Dc = 1.620 g/cm3, Z = 2, F(000) = 1444, μ(MoKα) = 1.857 mm-1, R = 0.0523 and wR = 0.0982 for 3219 observed reflections (I ＞ 2σ(I)). Structural analysis shows that the zinc atom is coordinated with three oxygen atoms from two ferrocenemonocarboxylates and one water molecule together with two nitrogen atoms from 2,2′-bipyridine, giving a distorted square-pyramidal coordination geometry. The complex molecules are linked to form an infinite one-dimensional chain by both intermolecular hydrogen bonds and π-π stacking interactions of the bipyridine rings.