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1.
Povilas Vainilavicius Romualdas Smicius Virginija Jakubkiene Sigitas Tumkevicius 《Monatshefte für Chemie / Chemical Monthly》2001,132(7):825-831
Summary. In the reaction of 5-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)-methyl-1,3,4-oxadiazole-2-thione with hydrazine
hydrate, 5-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)-methyl-4-amino-1,2,4-triazole-3-thione was formed. The reactions
of the latter with ethyl bromoacetate and chloroacetonitrile in the presence of triethylamine proceeded under formation of
the corresponding S-alkylated derivatives, whereas from its reaction with ω-bromoacetophenone and ethyl 4-chloroacetoacetate
triazolothiadiazines were obtained. Treatment of the title compound with ethyl 2-chloroacetoacetate led to the formation of
5-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)-methyl-4-N-acetylamino-(3-ethoxy-carbonylmethylthio)-1,2,4-triazole.
Performing of the latter reaction without basic catalyst gave a triazolothiadiazine. Treatment of the S-alkylated derivatives
with sodium methoxide resulted in triazolothiadiazines via a cyclocondensation reaction.
Received November 20, 2000. Accepted January 15, 2001 相似文献
2.
A novel polymer-forming diimide–diacid, 5,5′-bis[4-(4-trimellitimido phenoxy)phenyl]-hexahydro-4,7-methanoindan (II), was prepared by the condensation reaction of 5,5′-bis[4-(4-aminophenoxy)phenyl]-hexahydro-4,7-methanoindan with trimellitic
anhydride. A series of novel aromatic poly(amide–imide)s (PAIs) containing polycyclic cardo groups was prepared by the direct
polycondensation of II with various aromatic diamines using phosphorylation techniques. The polymers had inherent viscosities between 0.71 and 0.96 dl/g.
The polymers were soluble in polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide (DMAc) and N,N-dimethylformamide, and could be cast from their DMAc solutions into transparent, flexible, and tough films, except for III
a
. These films had yield strengths of 85–114 MPa, tensile strengths of 77–102 MPa, an elongation at break of 8–17%, and initial
moduli of 2.0–2.7 GPa. Wide-angle X-ray diffraction revealed that the polymers are amorphous. The glass-transition temperatures
of the polymers were in the range 242–312 °C. All the PAIs exhibited no appreciable decomposition below 430 °C, and their
10%-weight-loss temperatures were in the range 484–507 °C in nitrogen and 494–515 °C in air.
Received: 26 January 1999 Accepted in revised form: 11 May 1999 相似文献
3.
Małgorzata T. Kaczmarek Maciej Kubicki Wanda Radecka-Paryzek 《Monatshefte für Chemie / Chemical Monthly》2006,137(8):997-1003
Summary. The new zinc complex of the N,N′-bis(salicylidene)-4-methyl-1,3-phenylenediamine ligand as a product of the [2 + 1] Schiff base condensation process was synthesized in the one-step metal-promoted reaction between salicylaldehyde and 4-methyl-1,3-phenylenediamine
in ethanol in the presence of zinc chloride. The two potentially tetradentate N2O2
Schiff bases function as neutral monodentate ligands involving only one oxygen atom in coordination. This rare coordination pattern
of a mononuclear salen-type zinc complex was revealed by X-ray crystallography and correlated with spectroscopic characterization. 相似文献
4.
Edith Gößnitzer Winfried Wendelin Karl Schermanz Karin Frieberger 《Monatshefte für Chemie / Chemical Monthly》2001,132(9):1081-1093
Summary. The reaction of 2-benzylidenecyclohexanone and 1-(4-methoxyphenyl)-2-methyl-1-penten-3-one with guanidine did not yield the
expected 4-phenylhexahydro-2-quinazolinamine and 4-(p-methoxyphenyl)-dihydro-2-pyrimidinamine, respectively, but nitrogen-free products which turned out as [3+3]- and [4+2]-cycloadducts
of two molecules of the applied vinylogous ketone each. According to elemental analyses, mass spectra, and, in particular,
NMR analyses (1H and 13CNMR, HH-COSY, gs-HSQC, gs-HMBC, 1D TOCSY, NOESY, and 1D NOE difference spectra), the prepared dimers were identified as racemic (5E)-5-benzylidene-9β-phenyl-trans-4a-1,2,3,4,4a,5,6,7,8,9a-decahydroxanthen-4aα-ol and 3β,5β-bis-(4-methoxyphenyl)-2α,4β,6α-trimethyl-4α- propionylcyclohexanone, respectively. Structure and stereochemistry of the dimers
are elucidated, and mechanisms for their formation are proposed.
Received April 11, 2001. Accepted (revised) May 18, 2001 相似文献
5.
Summary. The reaction of 1,5-diphenylpentanetrione, 4-chlorobenzaldehyde, and acetone in the presence of methylamine resulted in 2,6-dibenzoyl-5-(4-chlorphenyl)-3-methyl-cyclohex-2-en-1-one,
which was formed by a sequence of a Knoevenagel reaction, an aldol condensation, and a Michael addition in a one-pot reaction.
Received August 16, 2000. Accepted September 8, 2000 相似文献
6.
Romualdas Smicius Virginija Jakubkiene Milda M. Burbuliene Povilas Vainilavicius 《Monatshefte für Chemie / Chemical Monthly》2002,133(2):173-181
Summary. Treatment of 5-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)-methyl-1,3,4-oxadiazole-2-thione with haloalkanes yielded
oxadiazole S-alkyl derivatives, whereas its reaction with formaldehyde and amines resulted in formation of oxadiazole N(3)-aminomethyl
derivatives. The alkylation of 2-alkylsulfanyl-5-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)-methyl-1,3,4-oxadiazoles
with methyl bromoacetate proceeded at the N(1)-position of pyrimidine to give 2-alkylsulfanyl-5-(1-methoxycarbonylmethyl-6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)-methyl-1,3,4-oxadiazoles,
whereas aminomethylation, bromination, or nitration took place at position 5 of pyrimidine ring and afforded the corresponding
5-pyrimidine substituted derivatives.
Received May 9, 2001. Accepted (revised) August 17, 2001 相似文献
7.
Ma?gorzata T. Kaczmarek Maciej Kubicki Wanda Radecka-Paryzek 《Monatshefte für Chemie / Chemical Monthly》2006,14(5):997-1003
The new zinc complex of the N,N′-bis(salicylidene)-4-methyl-1,3-phenylenediamine ligand as a product of the [2 + 1] Schiff base condensation process was synthesized in the one-step metal-promoted reaction between salicylaldehyde and 4-methyl-1,3-phenylenediamine
in ethanol in the presence of zinc chloride. The two potentially tetradentate N2O2
Schiff bases function as neutral monodentate ligands involving only one oxygen atom in coordination. This rare coordination pattern
of a mononuclear salen-type zinc complex was revealed by X-ray crystallography and correlated with spectroscopic characterization. 相似文献
8.
Franz Pertlik 《Monatshefte für Chemie / Chemical Monthly》2001,132(12):1509-1513
Summary. Single crystals of K2Ag12Te7 (a = 11.460(2), c = 4.660(1) ?; V = 530.01 ?3; space group: P63/m; Z = 1) were synthesized under hydrothermal conditions at 250°C in concentrated aqueous KOH solution from elementary silver
and tellurium. The crystal structure is characterized by trigonal prismatic KTe6 polyhedra, connected via two common faces to KTe3 rods parallel to [001]. These rods are combined by two crystallographically independent Ag atoms, each coordinated to four
Te and three Ag atoms (Ag–Te and Ag–Ag < 3.1 ?) to a framework of the formula (K2Ag12Te6)2 + and with channels parallel to the sixfold axis. These channels are statistically occupied by one further Te atom per unit
cell, distributed over two independent positions.
Received May 17, 2001. Accepted (revised) July 3, 2001 相似文献
9.
Summary. The influence of reaction conditions (temperature, type of catalyst, time) on the base-catalyzed reaction of mono-, di-,
and trialkylphosphates (alkyl = methyl, ethyl, i-propyl, n-butyl) with Ca2+ ions and on the structure and composition of the reaction products was studied. The composition of the calcium phosphates
depends mainly on the reaction temperature. At temperatures below 100°C, a nanocrystalline solid product transforming into
dicalcium phosphate by heating (calcination) was found. Pure nanocrystalline hydroxyapatite was prepared by hydrothermal synthesis
at 160°C from mono- and dialkylphosphates. The size of hydroxyapatite crystallites was about 1 nm, the particle size about
150 nm. Agglomerated particles of hydroxyapatite larger than 2 μm were prepared at 200°C. Hydrothermal reaction of trialkylphosphates
with Ca2+ ions at 200°C produced CaHPO4. The experimental results were used to propose a reaction mechanism for base-catalyzed hydrothermal reactions of alkylphosphates
with Ca2+ ions.
Received October 4, 2001. Accepted (revised) November 19, 2001 相似文献
10.
Summary. The two new compounds Mn(dien)2[MoS4] (1) and Mn(dien)2[Mo2O2S6] (2) (dien = diethylenetriamine) were prepared under solvothermal conditions. Both compounds were obtained as phase-pure products. The
structures consist of new [Mn(dien)2]2+ cations and isolated tetrahedral [MoS4]2− (1) or [Mo2O2S6]2− (2) anions. Between the anions and the cations, hydrogen bonding is observed. Compound 1 crystallizes in the tetragonal space group I (a = 10.219(2), c = 9.259(2) ?, Z = 2), whereas 2 crystallizes in the monoclinic space group P21/c (a = 8.703(2), b = 18.390(4), c = 14.603(3) ?, β = 103.18(3)°, Z = 4). The thermal behaviour of the thiomolybdates was investigated using difference thermoanalysis (DTA) and thermogravimetry
(TG). Both compounds decompose under argon with a single endothermic signal in the DTA curve (peak maximum: 252 (1) and 242°C (2)).
Received November 5, 2001. Accepted December 27, 2001 相似文献
11.
Nasser R. El-Brollosy Mohamed F. Abdel-Megeed Afaf R. Genady 《Monatshefte für Chemie / Chemical Monthly》2001,132(9):1063-1073
Summary. A facile and efficient synthesis of a series of novel 1,2,4-triazolo[5,1-b]quinazolines is described. 2,3-Diaryl-2,3-dihydro-1H-1,2,4-triazolo[5,1-b]quinazolin-9-ones were obtained by reaction of 3-amino-2-arylamino-3H-quinazolin-4-ones with aromatic aldehydes as well as by ring closure of the corresponding anils. Treatment of 3-amino-2-arylamino-3H-quinazolin-4-ones with aromatic carboxylic acids afforded 2,3-diaryl-3H-1,2,4-triazolo[5,1-b]quinazolin-9-ones which could also be synthesized by dehydrogenation of the corresponding dihydro derivatives. Reaction of
3-amino-2-arylamino-3H-quinazolin-4-ones with diethyl malonate and acetylacetone gave 3-aryl-3,9-dihydro-9-oxo-1,2,4-triazolo[5,1-b]quinazolin-2-yl-acetic acid ethyl ester and 3-aryl-2-methyl-3H-1,2,4-triazolo[5,1-b]quinazolin-9-ones, respectively. The latter compounds were also prepared via reaction with acetic anhydride, whereas acetylation with acetic anhydride in the presence of pyridine afforded the acetyl
derivatives.
Received March 22, 2001. Accepted (revised) May 11, 2001 相似文献
12.
Steven Van Petegem Danny Segers Charles Dauwe Florian dalla Torre Helena Van Swygenhoven 《Monatshefte für Chemie / Chemical Monthly》2002,133(6):829-836
Summary. Nanostructured Ni3Al was produced by the inert gas condensation and in situ compaction technique and characterized by means of high-resolution transmission electron microscopy (HRTEM), X-ray diffraction,
and density measurements. The defect structure was investigated using positron annihilation lifetime spectroscopy (PALS).
It is shown that in some samples besides the cubic also the martensitic phase can be present. The defect structure can be
divided into three major components: vacancy-like defects in the grain boundaries and nano-voids with a size of 1 nm as seen
with PALS, and large pores with sizes up to 8 nm as seen with HRTEM. Furthermore, it is shown that an increasing compaction
temperature leads to significantly smaller nano-voids.
Received October 5, 2001. Accepted (revised) November 12, 2001 相似文献
13.
Summary. Small plate-like single crystals of MgAlF5(H2O)2 have been obtained during hydrothermal treatment (270°C) of microcrystalline material prepared by precipitation of stoichiometric
solutions of Al2(SO4)3 · 18H2O and Mg(NO3)2 · 6H2O with diluted hydrofluoric acid. The crystal structure of MgAlF5(H2O)2 has been refined from single crystal data (Imma (# 74), Z = 4, a = 7.0637(7), b = 10.1308(10), c = 6.7745(7) ?, 398 structure factors, 33 parameters, R(F2 > σ(F
2)) = 0.0245, wR(F2 all) = 0.0525). Main features of the inverse weberite type structure are infinite chains of trans-bridged [AlF6] octahedra which are connected via common fluorine atoms by isolated [MgF4(H2O)2] octahedra. MgAlF5(H2O)2 dehydrates at temperatures above 300°C to give MgAlF5. XRPD analysis of this phase has revealed isotypism with FeAlF5. The crystal structure of MgAlF5 (Immm (# 71), Z = 2, a = 7.268(1), b = 6.123(2), c = 3.543(1) ?) is built of infinite chains of edge-sharing [MgF6] octahedra and chains of corner-sharing [AlF6] octahedra along [001]. Upon further heating to temperatures above 500°C, MgAlF5 decomposes to MgF2 and α − AlF3.
Received January 15, 2001. Accepted February 12, 2001 相似文献
14.
The reaction of 1,5-diphenylpentanetrione, 4-chlorobenzaldehyde, and acetone in the presence of methylamine resulted in 2,6-dibenzoyl-5-(4-chlorphenyl)-3-methyl-cyclohex-2-en-1-one, which was formed by a sequence of a Knoevenagel reaction, an aldol condensation, and a Michael addition in a one-pot reaction. 相似文献
15.
Susana H. Tarulli Oscar V. Quinzani Oscar E. Piro Enrique J. Baran Eduardo E. Castellano 《Monatshefte für Chemie / Chemical Monthly》2001,132(7):779-787
Summary. The crystal structure of the title complex, [Cd(tsac)2(H2O)], has been determined by single crystal X-ray diffraction methods. It crystallizes in the monoclinic space group C2/c (a = 12.236(3), b = 8.919(3), c = 16.655(3) ?, β = 96.18(2)°, Z = 4). The molecular structure was solved from 1705 independent reflections with I > σ(I) and refined to R
1 = 0.0489. Infrared and Raman spectra of the complex were recorded and are briefly discussed. Its thermal behaviour was investigated by thermogravimetry
and differential thermal analysis.
Received December 18, 2000. Accepted February 19, 2001 相似文献
16.
Summary. N′-Arylacetonitrilimines were generated from acetohydrazonyl chlorides and reacted with mercaptoalkanoic acids forming 4-aryl-5-oxo-3-thiahexanoic
acids. These were cyclized by reaction with dicyclohexyl carbodiimide yielding 2-acetyl-4-aryl-6H-1,3,4-thiadiazin-5-ones.
Received November 13, 2001. Accepted January 9, 2002 相似文献
17.
A synthesis of novel derivatives of 6-methyluracil, 6-methyl-2-thioxo-, and 2-imino-6-methyl-2,3-dihydro-1H-pyrimidin-4-one
containing a 2-(phenoxy)ethyl substituent at position 5 of the pyrimidine ring has been carried out. It was found that 5-[2-(phenoxy)ethyl]
derivatives of 6-methyl-2-thioxo- and 2-imino-6-methyl-2,3-dihydro-1H-pyrimidin-4-one are obtained by the condensation of
the corresponding ethyl 3-oxo-2-(2-phenoxyethyl)butanoates with thiourea or guanidine. 6-Methyl-5-[2-(phenoxy)ethyl]uracils
can be prepared by treating 6-methyl-5-[2-(phenoxy)ethyl]-2-thioxo-2,3-dihydro-1H-pyrimidin-4-ones with an excess of aqueous
monochloroacetic acid solution.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1213–1217, August, 2005. 相似文献
18.
R. Vaickelioniene V. Mickevicius G. Mikulskiene 《Chemistry of Heterocyclic Compounds》2004,40(6):767-775
We have studied condensation of 1-(4-bromophenyl- and 2,5-dimethylphenyl)-3-ethoxycarbonyl-2-methyl-1,4,5,6-tetrahydro-4(1H)pyridones with hydrazine, phenylhydrazine, and hydroxylamine, as a result of which we obtained nucleophilic substitution and intramolecular cyclization products: 5-(4-bromophenyl- and 2,5-dimethylphenyl)-4-methyl-2,5,6,7-tetrahydro-3H-pyrazole[4,3-c]pyridin-3-ones, 5-(4-bromophenyl- and 2,5-dimethylphenyl)-4-methyl-6,7-dihydroisoxazole[4,3-c]pyridin-3(5H)-ones. We used computer modeling of the molecules of the studied compounds to obtain additional information on the structural features of the reaction products. 相似文献
19.
4-(2-Hydroxy-phenyl)-but-3-en-2-one (1) was prepared via condensation of salicylaldehyde with acetone, and then reaction of the ketone 1 with thiosemicarbazide was accompanied by cyclization to give substituted pyrazole (2). Seven new 5-(2-hydroxy-phenyl)-3-methyl-4,5-dihydropyrazole-1-carbothioamide derivatives (3a–3g) were synthesized by the acylation of 2 and characterized by means of elemental analysis, infrared (IR), and 1H nuclear magnetic resonance (NMR). The compounds 3c, 3d, and 3g showed certain bactericidal activity against E. coli; while compound 3g showed certain bactericidal activity against P. vulgaris.
Translated from Chinese Journal of Applied Chemistry, 2006, 23(12): 1355–1358 [译自: 应用化学] 相似文献
20.
Summary. Stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reaction between 1-methylparabanic
acid (1-methylimidazoline-2,4,5-trione) and dialkyl acetylenedicarboxylates in the presence of triphenylphosphine. These ylides
exist in solution as a mixture of two geometric isomers. This is due to the restricted rotation around the carbon–carbon partial
double bond resulting from conjugation of the ylide moiety with the adjacent carbonyl group. These ylides undergo smooth intramolecular
Wittig reaction followed by an electrocyclic ring opening to produce dialkyl (E)-2-(1-methyl-2,5-dioxo-3-imidazolin-4-yl)-but-2-enedioates in good yields.
Corresponding author. E-mail: isayavar@yahoo.com
Received March 26, 2002; accepted (revised) April 24, 2002 相似文献