4H-3,1-benzoxazines. 2. Synthesis of 2,4-substituted 1,2-dihydro-4H-3,1-benzoxazines

The reactions of o-aminophenylcarbinols with carbonyl compounds have been studied. Optimum conditions have been developed for the synthesis of 2-(5-X-2-furyl)-1,2-dihydro-4H-3,1-benzoxazines. It was found that 2,2-disubstituted 1,2-dihydro-4H-3,1-benzoxazines are unstable and are converted upon heating in the presence of acylating agents to 4H-3,1-benzoxazines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 842–847, June, 1988.     

Derivatives of isoquinoline. 30. Synthesis of 4-spirosubstituted dioxenoisoquinolines

Methods have been developed for the synthesis of 1,4-benzodioxanyl-6-ethylamine with cyclopentyl and tetrahydropyranyl substituents in the -position. These compounds have been used as starting materials for the synthesis of new heterocyclic systems, the 4-spirocyclosubstituted dioxinoisoquinolines.For Communication 29, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 677–680, May, 1993.     

Limits of detection and decision. Part 4

Probability density functions (PDFs) have been derived for a number of commonly used limit of detection definitions, including several variants of the Relative Standard Deviation of the Background–Background Equivalent Concentration (RSDB–BEC) method, for a simple linear chemical measurement system (CMS) having homoscedastic, Gaussian measurement noise and using ordinary least squares (OLS) processing. All of these detection limit definitions serve as both decision and detection limits, thereby implicitly resulting in 50% rates of Type 2 errors. It has been demonstrated that these are closely related to Currie decision limits, if the coverage factor, k, is properly defined, and that all of the PDFs are scaled reciprocals of noncentral t variates. All of the detection limits have well-defined upper and lower limits, thereby resulting in finite moments and confidence limits, and the problem of estimating the noncentrality parameter has been addressed. As in Parts 1–3, extensive Monte Carlo simulations were performed and all the simulation results were found to be in excellent agreement with the derived theoretical expressions. Specific recommendations for harmonization of detection limit methodology have also been made.     

Solution thermodynamics of first-row transition elements. 4. Apparent molal volumes of aqueous ZnSO4 and CuSO4 solutions from 15 to 55°C

The apparent molal volumes of ZnSO ₄ and CuSO ₄ have been determined from density data over the temperature range 15–55°C and concentration range 0–15 molal. The volume data have been fitted to the Pitzer formalism over the entire temperature and concentration range. The volume changes for the formation of ZnSO ₄ and CuSO ₄ ion pairs have been estimated over the temperature range covered and the partial molal volumes of ZnSO ₄ and CuSO ₄ ion pairs have been derived. The results were used to explain the hydration structure of the ion pair. UV spectral effects accompanying a change of temperature in the 15–65°C range in CuSO ₄ solution indicate direct coordination of sulfate anion to the cupric cation. The process is favored by an increase in temperature.     

Heterocyclic steroids. X. 2-Aza-4-oxa-steroid analogs

Two 2-aza-4-oxa steroids have been synthesized from acid Ia. In addition the Beckmann rearrangement of the C-1 amide Ij has been explored.     

New reactions of deoxyvasicinone. Part 4

Analogues of deoxyvasicinone (1) in which the pyrrolo ring is substituted, enlarged, or attached to the a face of the quinazolone system were prepared and several reactions of these analogues with electrophilic reagents have been investigated.     

The Structure of Cellulose by Conformational Analysis. Part 4. Crystalline Cellulose II

The Kolpack, Weih, and Blackwell antiparallel central chain model was found to be the most energetically stable for the crystalline structure of cellulose II. Computational results indicated that the two most probable Sarko models are considerably less stable and less probable. The conformations of the monomers terminating the crystalline zone have been described. The predominance of van der Waals and H-bond interactions in the crystalline zone have been confirmed, and the H-bond values, locations, and distribution in the crystalline zone have been accurately mapped. The cellulose II crystallite has been confirmed to be considerably more stable than the cellulose I crystallite. Positions of atomic groups from the ab initio conformational analysis are consistent with the x-ray data for the Kolpack, Weih, and Blackwell model.     

Cinnoline chemistry XIII. 4-aziridinocinnolines

Nine substituted 4-aziridinoeinnolines have been prepared and subjected to anticancer screening. J. Heterocyclic Chem., 15 , 1039 (1978)     

Pyrazolato and related anions. Part V. Transition metal salts of 4-methylpyrazole

Summary Cd^II, Zn^II, Co^II, Ni^II, Cu^II and Ag^I salts of 4-methylpyrazole have been synthesized and compared with those of 3(5)-methylpyrazole and 3,5-dimethylpyrazole. The compounds were characterized and identified by vibrational spectra, ligand-field spectra and chemical analyses. The pyrazolate ion acts as a bidentate ligand in all cases. Tetrahedral and square-planar coordinations have been observed. Tentative assignments of the vibrational spectra of salts and neutral ligand have been made.     

Über Chalkogenolate. 175. Reaktion von Acetamidin mit Kohlenstoffdisulfid 4. Darstellung und Charakterisierung der N-Acetimidoyldithiocarbamidsäure

On Chalcogenolates. 175. Reaction of Acetamidine with Carbon Disulfide. 4. Synthesis and Characterization of N-Acetimidoyl Dithiocarbamic Acid Orange colored N-acetimidoyl dithiocarbamic acid has been prepared by reaction of the acetimidinium salt in aqueous solution with hydrochloric acid at 0°C. The properties and the thermal behaviour of the acid have been described, its decomposition in solution has been studied at 20°C kinetically.     

Formation and nitration heats for 3-nitro-4-chloro- and 3,5-dinitro-4-chloro-benzotrifluoride. Dinitration reaction investigation

Although various authors have determined the heats of combustion of many halogen derivatives we still do not have at our disposal data concerning the 3-nitro-4-chlorobenzotrifluoride and the 3,5-dinitro-4-chlorobenzotrifluoride.The object of this study has been that of determining the thermochemical constants for the above mentioned compounds. The values of the heats of combustion and of formation have been determined experimentally and from them the heats of nitration. These data and those determined with Handrick's method (group's energy contribution) have been compared with the heats of reaction carrying the nitration into an adiabatic system.Afterwards it has been investigated how to get the maximum output for the dinitro production. Data and considerations are reported.     

Reactions of aminoquinolines with unsaturated carboxylic acids. 4. Synthesis of 4-carboxy-1-quinolyl-2-pyrrolidinones

1-Quinolyl-4-carboxy-2-pyrrolidinones have been synthesized by the reaction of aminoquinolines with itaconic acid. Decyclization of the products gave 2-(quinolylaminomethyl)succinic acids.For Communication 3, see [1].Kaunus Technological University, Kaunas 3028, Lithuania Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 932–935, July, 2000.     

Electropolymerization of aminophthalic acids. I. Polymerization of 4-aminophthalic acid

4-Aminophthalic acid has been polymerized in almost quantitative yield to low molecular weight polymer by electrochemical initiation at a platinum anode. Systems involving the acid, amine salt, and the ammonium salt have been explored; the acid and/or the amine salt of the acid provides the best means of obtaining polymer. Maximum molecular weight is attained in a very short time at low current densities (～2 hr at 50 mA). Thermogravimetric data indicate a temperature stability comparable to polyamide-imide polymers (400°C). Long reaction times and high current densities decrease molecular weight and polymer yield.     

Stabilitätskonstanten der Kupferkomplexe von Acetessigsäureamiden. I

The stability constants of the copper complexes of acetoacetdialkylamides and substituted acetoacetanilides have been determined by potentiometric pH-measurements. The variation of stability constants with phenyl substituents is interpreted.     

4-hydroxy-2-quinolones. 110. Bromination of 1-r-4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acid anilides

1-R-4-Hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acid anilides have been prepared. It has been shown experimentally that these compounds are brominated by molecular bromine in glacial acetic acid at position 4 of the anilide fragment. The antitubercular properties of the compounds synthesized are discussed. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1508–1516, October, 2006.     

The synthesis of 6,7-dihydro-5H-pyrrolo[3,4-d]pyrimidines. II. 4-Hydroxy, 4-mercapto, 2-amino-4-hydroxy and 2,4-dihydroxy derivatives

Several new types of compounds in the 6,7-dihydro-5H-pyrrolo[3,4-d]pyrimidine series have been prepared. Included are a 6-acyl derivative unsubstituted in the pyrimidine ring, as well as 4-hydroxy, 4-mercapto, 2-amino-4-hydroxy and 2,4-dihydroxy derivatives. These products were derived directly or indirectly from 4-cyano- or 4-carbethoxy-1-acyl-3-amino-3-pyrroline intermediates. 3-Hydroxy, 3-amino, and 3-thioformylamino-1-acyl-3-pyrroline-4-thiocarboxamides have been obtained and the 3-thioformylamino derivatives shown to undergo base-catalyzed cyclization to close a 4-mercaptopyrimidine ring.     

Oxidation of acetanilide by MnO 4 − in the presence of HClO4. A kinetic study

The permanganate ion oxidation of acetanilide was studied spectrophotometrically by measuring the changes in absorbance at 525 nm in perchloric acid solutions. At lower [H⁺], the formation of an intermediate was observed whereas at higher [H⁺], the nature of reaction-time curve was sigmoid. The reaction rate increases with [H⁺] and the kinetics reveals complex order dependence in [H⁺]. The kinetic data for the oxidation of acetanilide indicate that the mechanism involves two steps. The order in [acetanilide] was found to be one. Water soluble Mn(IV) has been identified as an intermediate in the reduction of MnO ₄ ⁻ by acetanilide. The hydrogen ions have been found to decrease the stability of the Mn(IV). Externally added Mn(II) (a product of the reaction) has a composite effect (inhibition and catalysis). The addition of F⁻in the form of NaF has no effect on the reaction rate. The Arrhenius equation was valid for the reaction between 40 and 60 °C. The energy of activation, enthalpy and entropy of activation have been evaluated. Mechanisms consistent with the observed kinetics results have been suggested.     

Analogs of D(+)-pantothenic acid. VI. Synthesis of D-, L-, and DL-4′-amino-4′-deoxypantothenic acid

A new analog of pantothenic acid, DL-4-amino-2-hydroxy-3,3-dimethylbutanoic acid, has been synthesized and it has been separated into stereoisomer. D-, L-, and DL-N-(4-Amino-2-hydroxy-3,3-dimethylbutyryl)-β-alanines — amino analogs of pantothenic acid — have been synthesized by the condensation of the N-hydroxysuccinimide esters of N-BOC-D-, -L-, and -DL-4-amino-2-hydroxy-3,3-dimethylbutanoic acids with β-alanine, followed by the elimination of the protective groups.     

Nitrogen bridgehead compounds,part 68. Studies on quinolizine derivatives. Part 2. Synthesis of 1,3-disubstituted-4H-quinolizine derivatives

Quinolizine compounds 1 and 2 or their monocyclic tautomers 3 and 4 have been synthesized using 2-pyri-dineacetic acid derivatives 6a, b, A, B and ethoxymethylenemalonic acid derivatives 7a, b, c in base catalyzed or thermic reaction. In the 6-unsubstituted series, both the 4-oxo and 4-imino derivatives could have been obtained, in the 6-substituted series, however the 4-oxo ones only, whereas instead of the 4-imino derivatives, their monocyclic tautomers 3, 4 have been isolated. In the 6-unsubstituted series, the primarily formed 4-imino compounds have been rearranged into 4-oxo ones under stronger conditions. The structure of the isolated compounds have been proved by ultraviolet, infrared and ¹H nmr spectra, that of 3B=C by X-ray analysis as well.     

Unprecedented Cyclizations of Calix[4]arenes with Glycols under the Mitsunobu Protocol. Part 4. An Expedient Route to Thiacalix[4](Aza and Thia)Crowns

The Mitsunobu cyclization of p-t-butylthiacalix[4]arene with glycols was expanded to oligoethylene glycol analogues composed of O, S and N atoms in the chain. In this way a number of 1,3-thiacalix[4]monocrowns have been synthesized, offering simple and general access to a large variety of crowned thiacalixarenes. The binding properties of some ligands towards transition metal cations have been studied by ¹H NMR, UV/Vis spectroscopic and potentiometric methods.