Preparation of 2,4-dinitrophenyl derivatives of amino acids in dipolar aprotic solvents

Non-previously described new bis (3-nitropthalimide) arylenes activated with two carbonyls and containing flexible “bridging” groups, in particular dichloroethylene and ketones between the phthalimide fragments of the dinitrocompounds were obtained. The reactivity of the dinitrophthalimides used is determined, first of all, by the position of (3 or 4) nitro groups, and not by the nature of the Ar residue; monomers containing nitro groups in position 3 are more reactive than systems containing nitro groups in position 4. The interaction of synthesized bis (nitropthalimide) arylenes containing central dichloroethylene and ketone groups between phthalimide fragments and bis-phenolate derivatives of chloral was carried out. Synthesis of polyetherphthalimides using the process of polynitro substitution was carried out under modified conditions with complete absence of moisture. In general, the reactions of polynitro substitution proceed rapidly under relatively mild conditions; when dipolar aprotic solvents or a mixture of them with toluene are used, relatively high molecular weight polymers are formed. It has been established that the rate of dissolution of monomers is an important factor affecting the reaction rate; this determines the possibility of the formation of relatively high-molecular polymers, even with some deviation from the equimolarity of the monomers. As the general conditions for the synthesis of polyetherphthalimides based on synthesized bis (3-nitropthalimide) arylenes and bis-phenols, the optimal conditions were: reaction temperature -60 °C, reaction time -1 h with equimolar monomer ratio and concentration of each of them 0.25 mol/l. The influence of moisture on the synthesis of polyetherimides using the reaction of nucleophilic polynitro substitution was studied. It is shown that the process in the maximally dry system in the DMSO medium or (DMSO / toluene) leads to the formation of polymers with hr at least 0.63 dl/g. All the polymers obtained are readily soluble in dipolar and aprotic solvents. The structure of all the obtained intermediates and monomers was confirmed by elemental analysis and IR spectroscopy. An analysis of the primary thermal characteristics of the polymers obtained showed that they are characterized by relatively high and near destruction temperatures was found that the largest oxygen index (CI) in polymers, where more macromolecules contain more dichloroethylene fragments, and the lowest CI in polymers with a high oxygen content. It is shown that the polymers obtained have satisfactory deformation-strength characteristics. A feature of synthesized polyetherphthalimides is a significant difference between the temperatures of intensive destruction and softening temperatures, which determines the possibility of their processing into products by injection molding.

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ChemInform Abstract: Behavior of Amino Acids and Aliphatic Aldehydes in Dipolar Aprotic Solvents: Formation of Oxazolidinones.

ChemInform ◽

10.1002/chin.198941174 ◽

1989 ◽

Vol 20 (41) ◽

Author(s):

F. ORSINI ◽

F. PELIZZONI ◽

M. FORTE ◽

M. SISTI ◽

G. BOMBIERI ◽

...

Keyword(s):

Amino Acids ◽

Aprotic Solvents ◽

Aliphatic Aldehydes ◽

Dipolar Aprotic Solvents

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Substances with antineoplastic activity. LIII. N-{δ-(4-pyrrolo[2,3-d]pyrimidinylthio)valeryl}amino acids and analogous derivatives of di- and triglycine

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19731438 ◽

1973 ◽

Vol 38 (5) ◽

pp. 1438-1444 ◽

Cited By ~ 1

Author(s):

R. Kotva ◽

A. Černý ◽

M. Semonský

Keyword(s):

Amino Acids ◽

Antineoplastic Activity ◽

Derivatives Of

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Solvation of ions by dipolar aprotic solvents and water. A CNDO/2 study

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19852493 ◽

1985 ◽

Vol 50 (11) ◽

pp. 2493-2508 ◽

Cited By ~ 1

Author(s):

Petr Kyselka ◽

Zdeněk Havlas ◽

Ivo Sláma

Keyword(s):

Binary Mixtures ◽

Quantum Chemical ◽

Chemical Method ◽

Molecular Structures ◽

Dimethyl Sulphoxide ◽

Ternary Mixtures ◽

Aprotic Solvents ◽

Quantum Chemical Method ◽

Solvation Of Ions ◽

Dipolar Aprotic Solvents

Solvation of Li+, Be2+, Na+, Mg2+, and Al3+ ions has been studied in binary mixtures with dimethyl sulphoxide, dimethylformamide, acetonitrile and water, and in ternary mixtures of the organic solvents with water. The CNDO/2 quantum chemical method was used to calculate the energies of solvation, molecular structures and charge distributions for the complexes acetonitrile...ion (1:1, 2:1, 4:1), dimethyl sulphoxide...ion (1:1), dimethylformamide...ion (1:1), and acetonitrile (dimethyl sulphoxide, dimethylformamide)...ion...water (1:1:1).

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1H and 13C NMR spectra of 2,2’-disubstitutedtrans-azobenzenes suitable for preparation of metallized azo dyes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19912160 ◽

1991 ◽

Vol 56 (10) ◽

pp. 2160-2168 ◽

Cited By ~ 6

Author(s):

Josef Jirman

Keyword(s):

Nmr Spectra ◽

Electron Pair ◽

Phenyl Group ◽

Aprotic Solvents ◽

1H And 13C Nmr ◽

Predominant Form ◽

Rapid Equilibrium ◽

Dipolar Aprotic Solvents ◽

Free Electron Pair ◽

C Nmr

The 1H and 13C NMR spectra have been measured of six trans-azobenzenes substituted at 2 and 2’ positions with substituents favourable for complex formation with a metal (OH, NH2, NHCOCH3, COOH). From the standpoint of NMR such substituted trans-azobenzenes are present in solution in a rapid equilibrium following from rotation around the bond between C-1 of phenyl group and N atom of azo linkage. The predominant form has the substituent in the syn-position with respect to the free electron pair of the nearer azo nitrogen atom. The equilibrium is affected by dipolar aprotic solvents (such as hexadeuteriodimethyl sulfoxide) by decreasing the presence of the predominant form by 1 to 11%.

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