Synthesis of polyamide-quinazolinediones from 2,2′-disubstituted bis(1,3,4-oxadiazolin-5-ones) and aromatic bis-o-amino esters

A novel class of polyamide-quinazolinediones was synthesized by the polymerization of 2,2′-disubstituted bis(1,3,4-oxadiazolin-5-ones) with aromatic bis-o-amino esters in m-cresol. The polymerization probably proceeded in the formation of ring-opening adducts, which in turn were cyclized by the elimination of alcohol to give polyamide–quinazolinediones. These polymers, which were soluble in polar aprotic solvents such as dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide, had, with one exception, reduced viscosities in the range of 0.12–0.32 dL/g. Thermogravimetric analyses indicated that they began to decompose at 310–360°C in air.     

Reaction of 5-methyl-1,3,4-thiadiazoline-2-thione with molecular iodine

Russian Chemical Bulletin - The formation of the n-σ* complex of 5-methyl-1,3,4-thiadiazoline-2-thione with molecular iodine of the composition C3H4N2S2·I2 in dilute chloroform solutions...     

Synthesis and molecular structure of 5-(1-aminoisoindolenin-3-ylidene-amino)-1,3,4-thiadiazole-2(3H)-thione

The structure of 5-(1-aminoisoindolenin-3-ylideneamino)-1,3,4-thiadiazole-2(3H)-thione was studied by X-ray diffraction analysis and UV and IR spectroscopy. In the crystal, the molecule of the title compound is planar in spite of the substantially shortened intramolecular N…S contact. The factors that determine the structure of the heterocycle, namely, the nature of the N…S interaction, conjugation effects, and the tautomerism, were analyzed based on quantum-chemical calculations performed by the AM1 method.     

Synthesis of polydihydropyridazinones from bis(3-benzoylpropionic acids) and aromatic dihydrazines

A new class of polydihydropyridazinones has been synthesized by the solution cyclopolycondensation in m-cresol of 4,4′-oxy- and 4,4′-ethylenebis(3-benzoylpropionic acids) with aromatic dihydrazines such as bis(4-hydrazinophenyl) sulfone and bis(4-hydrazinophenyl)methane. The polymers having inherent viscosities of 0.2–0.4 were highly soluble in a wide range of solvents including m-cresol, N,N-dimethylacetamide, and pyridine. Thermogravimetric analysis of the polydihydropyridazinones showed initial weight losses commencing at 290–350°C in both air and nitrogen.     

Synthesis of esters of bis(alkoxymethyl) phosphinic acids

Conclusions A method was developed for the production of esters of bis(alkoxymethyl)phosphonic acids, and some of these esters were synthesized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 710–716, 1969.     

Synthesis and properties of dicarboxylic acid bis (thietanyl) esters

The reactions of some dibasic carboxylic acids with thioepichlorohydrins in the presence of interphase catalysts were studied. The first representatives of bis(thietanyl) esters of dicarboxylic acids were synthesized and characterized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1619–1620, December, 1988.     

Synthesis of bis(aryloxymethyl)phosphonic acids and their esters

Conclusions Synthetic methods were developed and bis(aryloxymethyl)phosphonic acids and their esters were synthesized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 951–953, April, 1969.     

Synthesis of polyamide-pyrazolones from 2,2′-disubstituted bis(4-ethoxymethylene-5-oxazolone) and aromatic dihydrazines

A new class of polyamide-pyrazolones was synthesized by the vinylogous nucleophilic substitution polymerization, which was followed by rearrangement, from 2,2′-p-phenylenebis(4-ethoxymethylene-5-oxazolone) and aromatic dihydrazines. Solution polymerization was carried out in polar aprotic solvents under mild conditions to yield polymers having inherent viscosities in the range of 0.5–1.2 quantitatively. The polymer derived from bis(4-hydrazinophenyl) sulfone was readily soluble in strongly polar solvents, while that from bis(4-hydrazinophenyl)methane was partially soluble or swelled in these solvents. The polyamide-pyrazolones which are presumed to contain some intermediate oxazolone structure showed a low level of thermal stability.     

Synthesis and properties of stable aromatic bis(nitrile oxides)

A number of stable bis(nitrile oxides) based on dimesitylmethane and didurylmethane and their analogs in which two aromatic rings are joined by various bridging groups were synthesized. The thermal isomerization of the bis(nitrile oxides) to diisocyanates and the relative reactivities of the bis(nitrile oxides) in 1,3-dipolar cycloaddition to styrene were studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1398–1403, June, 1991.     

5-(2-芳氧甲基苯并咪唑-1一亚甲基)-1,3,4-噁二唑-2-硫酮的合成、晶体结构及生物活性研究

以2-芳氧甲基苯并咪唑-1-乙酰肼类化合物为原料在微波辐射条件下合成了10种尚未见文献报道的5-(2-芳氧甲基苯并咪唑-1-亚甲基)-1,3,4-噁二唑-2-硫酮衍生物,化合物结构经IR 1H NMR,13C NMR和元素分析进行了表征,6a晶体结构表明,该化合物通过分子间氢键自组装成了沿b轴无限延伸的一维链状超分子结构,属于单斜晶系,P21/c空间群,a=11.5484(13)A,6=16.5319(19)A,c=11.3595(14)A,β=108.755(2)°,Z=2,V=2053.6(4)A3,Dx=1.328 g/cm3,F(000)=860,μ=0.19 mm-1,R=0.060,wR=0.196.初步生物活性试验结果表明该系列部分化合物对油菜幼苗的生长具有明显的生长调节作用,并对枯草杆菌具有一定的抑制作用.     

Electron impact induced ortho effects in 2-nitro-substituted aromatic sulphides containing 2-pyridyl, 2-(5-methylthio-1,3,4-thiadiazolyl) and/or 2-(4-methyl-1,3,4-thiadiazolinyl-5-thione) moieties

The most significant mass spectral features of 14 title compounds are discussed with the aid of deuterium labelling experiments. The decomposition patterns of these compounds are strongly affected by several competing ortho effects, due to the interaction of the nitro function(s) with neighbouring electron-poor N-heterocycles. Very intense polycyclic ions are produced via addition-elimination reactions by loss of simple radicals (H˙, OH˙, NO₂˙) from the molecular ion, followed by the ejection of neutral molecules (HNO₂,CH₃SCN or CH₃NCS). In addition, primary or secondary intramolecular oxygen transfers, preceded or not by hydrogen migration, from the nitro group to the imino carbon via spirocyclic intermediates, are generally observed. Minor skeletal rearrangements, triggered by single or multiple intramolecular oxygen transfer to the bridgehead sulphur atom, followed by SO or SO₂ ejection, are also noticed.     

Synthesis and characterization of two new coordination supramolecular structures from a versatile unsymmetric 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione (Hpot) ligand

Two new inorganic–organic coordination networks based on a versatile and unsymmetric building block 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione (Hpot) and inorganic Co^II and Cd^II salts have been synthesized in mixed solvent media and structurally characterized by single-crystal X-ray diffraction analysis. Crystal Hpot (1) was obtained from methanol solution. Reaction of Co(NO₃)₂ · 6H₂O with Hpot afforded a neutral two-dimensional (2-D) porous coordination polymer {[Co(pot)₂] · 6H₂O}_n (2) with a (4,4) network, which shows a 3-D supramolecular network through O–H?O weak interactions. While substituting the transition metal ions used in 2 with Cd(NO₃)₂ · 6H₂O, a neutral 2-D coordination polymer [Cd₂(pot)₄]_n (3) with a (6,3) network which further extended to a 3-D supramolecular structure through versatile hydrogen bonds C–H?X (X = O, N and S) was obtained. It is remarkable that the building block “pot” anion exhibits versatile coordination modes in complexes 2 and 3. These results indicate that the versatile nature of this rigid unsymmetric ligand, together with the coordination preferences of the metal centers, plays a critical role in construction of novel coordination polymers. The properties of gas absorption, magnetism and luminescence of 2 and 3 have been investigated and discussed in detail.     

Synthesis, spectral and thermal studies of some organotin(IV) derivatives of 5-amino-3H-1,3,4-thiadiazole-2-thione

Some tri- and diorganotin(IV) compounds of the general formula, RnSnL4-n (where n=2, R=Me, n-Bu and Ph; n=3, R=Me, n-Bu, n-Pr and Ph; HL=5-amino-3H-1,3,4-thiadiazole-2-thione) have been synthesized by the reaction of RnSnCl4-n (where n=2 or 3, R=Me, n-Bu, n-Pr and Ph) and the sodium salt of the ligand. Oct2SnL2 was obtained by the reaction of Oct2SnO with HL in a 1:2 molar ratio under azeotropic removal of water. The bonding and coordination behavior in these derivatives are discussed on the basis of IR, Far-IR, multinuclear (1H, 13C and 119Sn) NMR and 119Sn M?ssbauer spectroscopic studies. These investigations suggest that in all the compounds the ligand acts as monoanionic bidentate coordinating through ring N(3) and exocyclic S. Thermal studies of five compounds, viz., Ph3SnL, Me2SnL2, n-Bu2SnL2, Oct2SnL2 and Ph2SnL2 have been carried out in the temperature range 25-1000 degrees C using TG, DTG and DTA techniques under an atmosphere of dry nitrogen.