Efficient and Convenient Deprotection of Thiocarbonyl to Carbonyl Compounds Using 3-Carboxypyridinium and 2,2′-Bipyridinium Chlorochromates in Solution,Dry Media,and under Microwave Irradiation

Summary. A synthetic utility of 3-carboxypyridinium (CPCC) and 2,2-bipyridinium (BPCC) chlorochromates in deprotection reactions is reported. Different types of thioamides, thioureas, thiono esters, and thioketones are deprotected to their corresponding carbonyl compounds with these reagents in good to excellent yields. The reactions were carried out in solution, under solvent-free conditions, and under microwave irradiation. The results show that with both reagents the rates of the reactions and the yields are usually highest under microwave irradiation.     

Efficient one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-ones from aromatic aldehydes and their one-pot oxidation to quinazolin-4(3H)-ones catalyzed by Bi(NO3)3·5H2O: Investigating the role of the catalyst

An efficient and novel synthesis of 2,3-disubstituted 2,3-dihydroquinazolin-4(1H)-ones via one-pot, three-component reaction of isatoic anhydride, primary amines and aromatic aldehydes catalyzed by Bi(NO₃)₃·5H₂O under solvent-free conditions is described. Oxidation of these 2,3-dihydroquinazolin-4(1H)-ones to their quinazolin-4(3H)-ones was also successfully performed in the presence of Bi(NO₃)₃·5H₂O. This new method has the advantages of convenient manipulation, short reaction times, excellent yields, very easy work-up, and the use of commercially available, low cost and relatively non-toxic catalyst. The role of Bi(NO₃)₃·5H₂O was also investigated in these transformations.     

Die thermische Zersetzung einiger Wismut-Doppelnitrate

Zusammenfassung Die Zersetzung von CsNO₃, Bi(NO₃)₃, Bi(NO₃)₃·5H₂O, BiONO₃, 2CsNO₃·Bi(NO₃)₃ und 3M(NO₃)₂·2Bi(NO₃)₃·24H₂O (M=Mg, Mn, Co, Ni, Zn) wurde thermogravimetrisch untersucht. Es wurde festgestellt, daß 2CsNO₃·Bi(NO₃)₃ über eine beständige Zwischenstufe 2CsNO₃+1/2Bi₂O₃, die Doppelnitrate 3M(NO₃)₂·2Bi(NO₃)₃·24H₂) über 3M(NO₃)₂+2BiONO₃ zerfallen. Eine Herabsetzung der thermischen Stabilität des CsNO₃ wegen der Anwesenheit von Bi₂O₃, und der NitrateM(NO₃)₂ wegen der Anwesenheit von BiONO₃ wurde beobachtet. Zugleich ist BiONO₃ von zweiwertigen Nitraten stabilisiert.

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The thermal decomposition of some bismuth double nitrates

The decomposition of CsNO₃, Bi(NO₃)₃, Bi(NO₃)₃·5H₂O, BiONO₃, 2CsNO₃·Bi(NO₃)₃, and 3M(NO₃)₂·2Bi(NO₃)₃·24H₂O (M=Mg, Mn, Co, Ni, Zn) has been studied by thermogravimetric analysis. It was found that 2CsNO₃·Bi(NO₃)₃ decomposesvia a stable intermediate, 2CsNO₃+1/2Bi₂O₃, and the double nitrates 3M(NO₃)₂·2Bi(NO₃)₃·24H₂)via 3M(NO₃)₂+2BiONO₃·Bi₂O₃ and BiONO₃ decrease the thermal stability of CsNO₃ andM(NO₃)₂, resp. Bivalent nitrates stabilize BiONO₃ to a certain degree.

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Auszug aus einem Teil der Magisterarbeit vonF. Lazarini.     

Gamma-ray induced decomposition of some divalent and trivalent nitrates

Gamma-ray induced decomposition of some divalent nitrates, viz. Mg(NO₃)₂·6H₂O, Ca(NO₃)₂·4H₂O, Sr(NO₃)₂, Ba(NO₃)₂, Zn(NO₃)₂·6H₂O, Cd(NO₃)₂·4H₂O, Hg(NO₃)₂·2H₂O, Mn(NO₃)₂·4H₂O, Cu(NO₃)₂·3H₂O and trivalent nitrates, viz. Al(NO₃)₃·9H₂O, Fe(NO₃)₃·9H₂O, Cr(NO₃)₃·9H₂O, Y(NO₃)₃·6H₂O, In(NO₃)₃·3H₂O, La(NO₃)₃·6H₂O, Ce(NO₃)₃·6H₂O, Pr(NO₃)₃·6H₂O, Bi(NO₃)₃·5H₂O has been studied in solid state at room temperature. G(NO ₂ ^– ) values (after applying appropriate dose correction) have been found to vary in the range 0.12–3.16 and 0.069–2.15 for divalent and trivalent nitrates respectively. G'-values were calculated by dividing G by the ratio of number of electrons in nitrate ion to the total number of electrons in the nitrate salt. Cation size, its polarizing power, available free space in the crystal lattice and the number and location of water molecules seem to play a dominant role in radiolytic decomposition. For Zn, Sr, In, La and Ce nitrates dose variation studies have been carried out.     

Bismuth compounds in organic synthesis. Bismuth nitrate catalyzed chemoselective synthesis of acylals from aromatic aldehydes

Aromatic aldehydes are smoothly converted into the corresponding acylals in good yields in the presence of 3-10 mol% Bi(NO₃)₃·5H₂O. Ketones are not affected under the reaction conditions. The relatively non-toxic nature of the catalyst, its ease of handling, easy availability and low cost make this procedure especially attractive for large-scale synthesis.     

Simple and efficient deprotection of 1,3-dithianes and 1,3-dithiolanes by copper(II) salts under solvent-free conditions

Aerobic solid state deprotection of 1,3-dithianes and 1,3-dithiolanes of aromatic and aliphatic aldehydes and ketones has been performed in excellent yields by Cu(NO₃)₂·2.5H₂O in the presence of montmorillonite K10 clay and sonic waves at room temperature. These dethioacetalizations proceed more slowly but efficiently under catalytic conditions by using 20% of the copper(II) salt with K10 clay and sonication.     

Complex compounds of metals with mixed acidoligands. Communication 9. Nitrate-sulfate complex compounds of bismuth(III)

Conclusions The authors have conducted the first synthesis of the nitrate-sulfate complex compounds of Bi(III) of the compositions CN₃H₆Bi(NO₃)₂SO₄, C₂N₂H₁₀BiNO₃(SO₄)₂, and (C₂N₂H₁₀)₅Bi₄(NO₃)₂(SO₄)₁₀·8H₂O. On the basis of an investigation of the IR spectra they suggest a hypothesis for their structures.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 487–491, March, 1982.     

Etude de l’isotherme 25°C du système quasi quaternaire H2O-Zn(NO3)2·6H2O-Cu(NO3)2·3H2O-NH4NO3;I- Isoplèthes 4 masse% NH4NO3, 8 ma

The solid-liquid equilibria of the quasi-quaternary system H₂O-Zn(NO₃)₂·6H₂O-Cu(NO₃)₂·3H₂O-NH₄NO₃ were studied at 25°C by using a synthetic method based on conductivity measurements. Three isoplethic sections has been established at 25°C and the stable solid phases which appear are: NH₄NO₃(IV), Zn(NO₃)₂·6H₂O, anhydrous Cu(NO₃)₂, Cu(NO₃)₂·3H₂O and metastable Cu(NO₃)·2.5H₂O. Neither double salts, nor mixed crystals are observed at these temperatures and composition range.     

Solubility Properties of the Systems Chromium Salts–Amino Acids–Water

Solubility properties of the ternary systems of Cr(NO₃)₃–His–H₂O, Cr(NO₃)₃–Met–H₂O, and CrCl₃–His–H₂O (His—histidine, Met—methionine) have been investigated in the whole concentration range by the phase equilibrium semimicromethod, and the corresponding phase diagrams have been constructed. It was shown that the new complexes Cr(His)(NO₃)₃ · 3H₂O, Cr(His)₂(NO₃)₃ · 3H₂O, Cr(His)₃(NO₃)₃ · 3H₂O, Cr(His)Cl₃ · H₂O, Cr(His)₂Cl₃ · H₂O, and Cr(His)₃Cl₃ · H₂O are formed in the Cr(NO₃)₃/CrCl₃–His–H₂O system, while Cr(Met)(NO₃)₃ · H₂O and Cr(Met)₂(NO₃)₃ · H₂O complexes are formed in the system Cr(NO₃)₃–Met–H₂O. Under the guidance of the phase diagrams, the complexes were prepared and characterized by chemical and elemental analysis, IR spectroscopy, and thermogravimetry data. The influences of metal cations, anions and the structures of amino acids on the formation of complexes were discussed.     

The role of anhydrous zinc nitrate in the thermal decomposition of the zinc hydroxy nitrates Zn5(OH)8(NO3)2·2H2O and ZnOHNO3·H2O

The steps associated with the thermal decomposition of Zn₅(OH)₈(NO₃)₂·2H₂O and ZnOHNO₃·H₂O are re-examined. Previous reports have suggested that Zn₅(OH)₈(NO₃)₂·2H₂O decomposes to ZnO via two intermediates, Zn₅(OH)₈(NO₃)₂ and Zn₃(OH)₄(NO₃)₂ whereas ZnOHNO₃·H₂O has been reported to decompose to ZnO via a Zn₃(OH)₄(NO₃)₂ intermediate. In this study, we demonstrate using TG, mass spectral analysis of evolved gases and in situ variable temperature powder X-ray diffraction analysis that, in fact, in the decomposition of Zn₅(OH)₈(NO₃)₂·2H₂O an anhydrous zinc nitrate intermediate is also involved. We, additionally, show that the decomposition of ZnOHNO₃·H₂O to ZnO also involves the formation of an anhydrous zinc nitrate intermediate. The anhydrous zinc nitrate formed in both cases is poorly crystallised and this observation may explain why this phase could not be observed by PXRD analysis in the previous studies.     

Copper(II)–lanthanide(III) 15-metallacrown-5 complexes based on pyrazinohydroxamic acid as new multiple-binding pentagonal platforms with Lewis amphoteric nature

Reaction of copper(II) acetate, lanthanium(III) or gadolinium(III) nitrate (1/5 equiv.) with pyrazinohydroxamic acid (H₂Pyzha) in DMF led to a series of new heterobimetallic 15-metallacrown-5 complexes. In a MeOH/H₂O solution the complexes exist as molecular unassociated metallacrowns. In solid state their structures are more complicated as it has been confirmed by X-ray analysis: discrete molecular metallacrowns [Gd(NO₃)₂{Cu(pyzha)}₅(DMF)₄(NO₃)] · 0.5C₆H₆ · H₂O (1), [Gd(NO₃)₂{Cu(pyzha)}₅(DMF)₅](NO₃) · 1.5DMF · 0.5H₂O (2), [La(NO₃)₂{Cu(pyzha)}₅(DMF)₅]NO₃ · 1.5DMF · 2C₆H₆ (3) are solvates, whereas compound [{La(NO₃)₂{Cu(pyzha)}₅(DMF)₅}₂(μ²-NO₃)](NO₃) · 3DMF (4) is a dimer, where μ-bridged nitrate links two copper centres of the adjacent metallamacrocycles. Complex [Gd(NO₃)₂{Cu(pyzha)}₅(DMF)₂(H₂O)(NO₃)] · CH₂Cl₂ · DMF (5) self-associates into a polymer chain by means of one pyrazine moiety and the copper ring atom. Reaction of the molecular metallacrowns with excess of inorganic salts CdBr₂ or Cu(OAc)₂ proceeds as anion methathesis process affording heteroanionic metallacrowns: molecular [Gd(NO₃)₂{Cu(pyzha)}₅(DMF)₅] [Gd(NO₃)₂{Cu(pyzha)}₅(DMF)₄(H₂O)][CdBr₄] · 1.5DMF (6), and 3D hydrogen bonded polymer [La(μ²-OAc)(H₂O)₃{Cu(pyzha)}₅ (H₂O)₄(NO₃)](NO₃) · 4H₂O (7).     

H2O + Fe(NO3)3 + Ni(NO3)2 ternary system isotherms at 0 °C and 30 °C

H₂O + Ni(NO₃)₂ binary system were investigated in the temperature range from −25 °C to 55 °C. The solid-liquid equilibria of the ternary system H₂O + Fe(NO₃)₃ + Ni(NO₃)₂ were studied using a synthetic method based on conductivity measurements. Tow isotherms were established at 0 °C and 30 °C, and the appearing stable solid phases are iron nitrate nonahydrate (Fe(NO₃)₃·9H₂O), iron nitrate hexahydrate (Fe(NO₃)₃·6H₂O), nickel nitrate hexahydrate (Ni(NO₃)₂·6H₂O) and nickel nitrate tetrahydrate (Ni(NO₃)₂·4H₂O).     

Extraction systems of flame atomic absorption determination of trace impurities in high purity nickel salts

Summary Different extraction sytems including long chain quaternary alkylammonium salts and APDC were investigated in order to determine the optimal conditions for extraction separation and preconcentration of traces of Ag, Bi, Cd, Cu, Fe, Mo, Pb, Sb and Zn from high purity NiSO₄·6H₂O, NiCl₂·6H₂O, Ni(OOCCH₃)₂·4H₂O and Ni(NO)₃)₂·6 H₂O. Best results for multielement preconcentration were found with the extraction system HCl-trioctylmethylammonium chloride-0,002 mol/l APDC/MIBK. The proposed method permits the flame atomic absorption determination of 5·10^–6%, Ag, Cd, Cu and Zn, 1·10^–5% Bi, Fe, Pb and 5·10^–5% Mo and Sb with good accuracy and precision.     

Complexes of Sn(II), Sn(IV), Pb(II) AND Bi(III) with selenourea

Conclusions Some new compounds of selenourea with Sn(II), Sn(IV), Pb(II) and Bi(III) were obtained, which had the composition: SnCl₂·2Seu, SnCl₄·4Seu, PbCl₂·2Seu, 2Pb(NO₃)₂·11Seu and Bi(NO₃)₃·6Seu.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1556–1557, July, 1971.     

New Cooling Mixtures Containing Sodium Acetate Trihydrate

Binary cooling mixtures consisting of CH₃COONa·3H₂O and NH₄NO₃, Al(NO₃)₃·9H₂O, or Ni(NO₃)₂·6H₂O were developed. They allow the initial temperature to be decreased by 18-19°C. Application of the mixtures does not require additional consumption of water.     

Dimethylphosphinato and dimethylarsinato complexes of Sb(III) and Bi(III) and their chemistry

Abstract  

The reaction of Me₂PO₂H and Me₂AsO₂H with SbCl₃, BiCl₃, and Bi(NO₃)₃·5H₂O gave the complexes Sb(Me₂PO₂)₃, Sb(Me₂AsO₂)₃, (Me₂PO₂)₂Bi-Cl, Bi(Me₂AsO₂)₃, (Me₂PO₂)₂Bi(NO₃), and (Me₂AsO₂)₂Bi(NO₃)·H₂O, respectively. The arsinato complexes did not react with the Lewis bases pyridine, Ph₃P, and Ph₃As in acetone. The compounds Sb(Me₂AsO₂)₃ and (Me₂AsO₂)₂Bi(NO₃)·H₂O reacted to a small extent with nicotinic acid in methanol but Bi(Me₂AsO₂)₃ gave (Me₂AsO₂-BiO) _x in good yields. (Me₂AsO₂)₂Bi(NO₃)·H₂O in methanol quantitatively rearranged to new complexes with the same composition, [(Me₂AsO₂)₂Bi(NO₃)·H₂O]′ and [(Me₂AsO₂)₂Bi(NO₃)·H₂O]″ in the presence of pyridine. With thiophenol in air, Sb(Me₂AsO₂)₃ gave PhSSPh and Me₂As-SPh (1:1 mol ratio), (Me₂AsO₂-SbO) _x and some Sb(Me₂AsO₂)₃ was reformed, Bi(Me₂AsO₂)₃ gave (Me₂AsO₂-BiO) _x , PhSSPh, and Me₂As-SPh (1:0.6 mol ratio), whereas (Me₂AsO₂)₂Bi(NO₃)·H₂O quantitatively gave PhSSPh, thus acting as a catalyst for the air oxidation of thiophenol.     

Bi(NO3)3.5H2O: A Convenient Reagent for Selective Oxidation of Sulfides to Sulfoxides

Bi(NO₃)₃.5H₂O, a cheaply available, crystalline solid has been found to readily effect selective oxidation of a variety of sulfides to sulfoxides in acetic acid medium at room temperature in fair to good yields.     

Regioselective N- and C2-electrophilic substitution of 3-substituted indoles

The reaction of 3-substituted indoles with 2-cyclohexenone under Lewis acid mediated conditions with Bi(NO₃)₃·5H₂O has been investigated. We have demonstrated that electrophilic substitution of 3-substituted indoles with 2-cyclohexenone will readily occur at the nitrogen. Furthermore, the extent of regioselectivity is dependent on reaction solvent and the C3-substituent. Excellent conversion is obtained with good to excellent isolated yields of N- and C2-adducts. In general, more polar, aprotic solvents (CH₃CN) give greater N-selectivity whereas with polar protic solvents (CH₃OH) an increase in the C2-adduct is observed.     

Anion effect on the construction of copper(II) coordination polymers with the twisted ligand bis(4-pyridylthio)methane

The reaction of CuSO₄ · H₂O with 4-bpytm [4-bpytm = bis(4-pyridylthio)methane] in EtOH afforded the complex [Cu(SO₄)(4-bpytm)(H₂O)₃] · H₂O (1 · H₂O) while the reaction of 4-bpytm with Cu(NO₃)₂ · 3H₂O in EtOH afforded the complex [Cu(NO₃)₂(4-bpytm)₂] · H₂O (2 · H₂O). The reaction of 4-bpytm with Cu(NO₃)₂ · 3H₂O in EtOH/dmf under microwave irradiation afforded the pseudo-polymorph [Cu(NO₃)₂(4-bpytm)₂] · Solv (2 · Solv). Compound 1 · H₂O forms helical chains while compounds 2 · H₂O and 2 · Solv are 2D coordination polymers with a (4,4) topology based on rhombic grids in 2 · H₂O and on a parquet motif in 2 · Solv. The 3D supramolecular organization through hydrogen bonding is analyzed for the three compounds and their thermal behaviour was also investigated.     

Bismuth nitrate-catalyzed multicomponent reaction for efficient and one-pot synthesis of densely functionalized piperidine scaffolds at room temperature

A simple, straightforward, and highly efficient diastereoselective multicomponent one-pot synthesis of a series of pharmaceutically interesting functionalized piperidine derivatives has been developed based on a low-cost and environmentally benign Bi(NO₃)₃·5H₂O catalyst via tandem reactions of 1,3-dicarbonyl compounds, aromatic aldehydes, and various amines in ethanol at room temperature. High atom-economy, good yields, eco-friendliness, and mild reaction conditions are some of the important features of this protocol.