Some 2-substituted derivatives of 5-(2-amino-6-hydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl)pentanoic acid

1981 ◽  
Vol 46 (6) ◽  
pp. 1397-1404 ◽  
Author(s):  
Rudolf Kotva ◽  
Jiří Křepelka ◽  
Antonín Černý ◽  
Vojtěch Pujman ◽  
Miroslav Semonský

On condensation of 6-substituted trialkyl esters of 2-carboxy-1,7-heptanedioic acids XIII-XXIII with guanidineand subsequent saponification 2-substituted 5-(2-amino-6-hydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl)pentanoic acids II-XII were prepared. From the pharmacological point of view some of the substances prepared had a potentiating effect on the antileukemia effect of 5-fluorouracil in mice and the antineoplastic effect manifested by a diminution of the tumours in animals with experimental tumours.

1982 ◽  
Vol 47 (9) ◽  
pp. 2525-2529 ◽  
Author(s):  
Rudolf Kotva ◽  
Jiří Křepelka ◽  
Jaroslav Vachek

Condensation of trialkyl esters of 6-substituted 2-carboxy-1,7-heptanedioic acids XII-XVII with urea or thiourea and subsequent saponification gave 2-substituted 5-(2,6-dihydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl)pentanoic acids II-VI or 5-(2-mercapto-6-hydroxy-4-oxo-3,4-dihydro-6-pyrimidinyl)pentanoic acids VII-XI, respectively. Compounds II, VII and X had a weak antineoplastic effect in animals with experimental transplantable tumours.


1980 ◽  
Vol 45 (12) ◽  
pp. 3583-3592 ◽  
Author(s):  
Miroslav Semonský ◽  
Antonín Černý ◽  
Jiří Křepelka ◽  
Rudolf Kotva ◽  
Bohumil Kakáč ◽  
...  

Condensation of 1,1,ω-alkanetricarboxylic acids triethyl esters XIV-XXI with guanidine gave ω-(2-amino-6-hydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl) alkanoic acids I-IV, VI-VIII, XIII of which some were converted to derivatives (ethyl ester V, N-acyl derivatives XI and XII). Similarly, triester XVII gave by condensation with urea or thiourea the analogous 5-substituted derivatives of barbituric acid X, and thiobarbituric acid IX, respectively. The structures of selected compounds of this group (IV, V, IX-XI and XIII) were determined by spectral methods. Of interest, from the pharmacological point of view, has proved compound IV, which exhibited a significant antineoplastic effect on some experimental tumours in mice and rats, and enhanced the action of some current cytostatics.


1983 ◽  
Vol 48 (1) ◽  
pp. 304-311 ◽  
Author(s):  
Jiří Křepelka ◽  
Jan Beneš ◽  
Vladimír Pouzar ◽  
Jaroslav Vachek ◽  
Jiří Holubek

Condensation of triethyl ester of 1,1,5-pentanetricarboxylic acid (XI) with substituted guanidines XXII - XXIX gave acids II - IX, which were converted into esters XI - XIX. The acid II and the ester XI were obtained as mixtures of positional isomers. Analogously, condensation of the triester XXI with dicyanodiamide gave rise to acid X, whose nitrile group, under conditions of esterification of a carboxyl group, produced iminoether XX. In pharmacological tests for antineoplastic activity the compounds prepared exhibited weaker efficacy than 5-(2-amino-6-hydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl)pentanoic acid (I), employed as standard.


Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1641 ◽  
Author(s):  
Ilya Nifant’ev ◽  
Andrey Shlyakhtin ◽  
Maxim Kosarev ◽  
Dmitry Gavrilov ◽  
Stanislav Karchevsky ◽  
...  

Catalytic ring-opening polymerization (ROP) of cyclic esters (lactides, lactones) and cyclic ethylene phosphates is an effective way to process materials with regulated hydrophilicity and controlled biodegradability. Random copolymers of cyclic monomers of different chemical nature are highly attractive due to their high variability of characteristics. Aryloxy-alkoxy complexes of non-toxic metals such as derivatives of 2,6-di-tert-butyl-4-methylphenoxy magnesium (BHT-Mg) complexes are effective coordination catalysts for homopolymerization of all types of traditional ROP monomers. In the present paper, we report the results of density functional theory (DFT) modeling of BHT-Mg-catalyzed copolymerization for lactone/lactide, lactone/ethylene phosphate and lactide/ethylene phosphate mixtures. ε-Caprolactone (ε-CL), l-lactide (l-LA) and methyl ethylene phosphate (MeOEP) were used as examples of monomers in DFT simulations by the Gaussian-09 program package with the B3PW91/DGTZVP basis set. Both binuclear and mononuclear reaction mechanistic concepts have been applied for the calculations of the reaction profiles. The results of calculations predict the possibility of the formation of random copolymers based on l-LA/MeOEP, and substantial hindrance of copolymerization for ε-CL/l-LA and ε-CL/MeOEP pairs. From the mechanistic point of view, the formation of highly stable five-membered chelate by the products of l-LA ring-opening and high donor properties of phosphates are the key factors that rule the reactions. The results of DFT modeling have been confirmed by copolymerization experiments.


1956 ◽  
Vol 34 (4) ◽  
pp. 502-514 ◽  
Author(s):  
Roger Gaudry ◽  
Louis Berlinguet ◽  
André Langis ◽  
Gérard Paris

A systematic investigation of the synthesis of 4-hydroxy-DL-proline and 2-amino-4-dihydroxyvaleric acid has been made, starting from the following derivatives of 2-amino-4-pentenoic acid: ethyl allylacetamidomalonate, ethyl allylacetamidocyanoacetate, 2-phthalimidopentenoic acid, allylacetamido-malonic acid, acetylallylglycine, 5-allylhydantoin, and 3-phenyl-5-allylhydantoin. Chlorine or bromine was added to the double bond of these compounds, and the reaction products were either derivatives of 5-halogenated-4-valerolactones or derivatives of 4,5-dihalogenated pentanoic acids, depending on whether the carboxyl group of the pentanoic acid was free or not when the halogenation reaction was carried out. Acid hydrolysis followed by treatment with barium hydroxide always gave mixtures, in different ratio, of 4-hydroxy-DL-proline and 2-amino-4,5-dihydroxyvaleric acid which were analyzed and isolated as the copper salts. In the case of 5-(2,3-dibromopropyl)hydantoin and 3-phenyl-5-(2,3-dibromopropyl)hydantoin, no cyclization could be obtained.


1950 ◽  
Vol 23 (1) ◽  
pp. 281-291 ◽  
Author(s):  
Jacques Gossot

Abstract The bonding process which has been described is of general application to all types of rubber mixtures, to metals, and to various other materials, without any change in composition of the bonding agent for the different materials. Although the problem of adhesion has been approached in this work only from the purely practical standpoint, it should be realized how little progress has been made in the theoretical knowledge of the problem. As a matter of fact, only a few authors have attempted to explain, on a basis of general concepts, certain special cases of adhesion, and there is still no real insight into the problem as a whole which might open the way to material progress. If one turns to the works of MacBain, Delmonte, and Buchan among the most important contributions to the phenomena of adhesion, the ultimate conclusion must be drawn that little has been accomplished in orienting investigations in this field toward more productive ends. From the physical point of view, particular attention must be paid to the condition of the state of the surface of the material to be bonded, to the surface tension, to the viscosity, and to the pH value of the adhesive. The chemical structure of the latter is that of a long-chain compound and, as has been proved conclusively in the present investigation, certain groups play a fundamental role, both in virtue of their chemical reactivity, and in virtue of the polar moment which they confer upon the molecule.


2020 ◽  
Vol 63 (9) ◽  
pp. 19-25
Author(s):  
Anna N. Davydova ◽  
◽  
Bulat T. Sharipov ◽  
Farid A. Valeev ◽  
◽  
...  

The enantioselective reduction of prochiral ketones is an important method for the preparation of enanti-enriched secondary alcohols, which can serve as starting materials for optically active compounds. Chiral metal hydride reagents, such as lithium aluminum hydride (LiAlH4) and sodium borohydride (NaBH4), modified with chiral ligands, have been developed to effect enantioselective reduction. However, in most cases, derivatives are used to obtain chiral hydride reagents, which are rare and hardly available. Therefore, the search for more accessible and effective derivatives suitable for the modification of hydride reagents is an urgent task. Levoglucosenone is an optically pure enone of carbohydrate nature, readily available by pyrolysis of any cellulose-containing materials. Levoglucosenone is considered a promising bioplatform for both laboratory synthesis and industrial use. The prospect of the development of chemistry of levoglucosenone and its derivatives in industry makes it possible to pay attention to these compounds from the point of view of studying their possibilities as chiral inducers or auxiliaries. In this work, we studied the possibilities of chiral induction in the reduction reactions of 1,3-diphenylpropan-1-one with hydride reagents obtained by replacing hydrogens in LiAlH4 and NaBH4 with hydroxy derivatives of levoglucosenone. The reduction of 1,3-diphenylpropan-1-one with chiral aluminum hydride reagents proceeded with low enantioselectivity, mainly with a predominance of (S)-1,3-diphenylpropan-1-ol. It was found that the enantiomeric purity of the S-stereomer decreases with an increase in the substitution of hydrogen atoms in LiAlH4 by hydroxy derivatives of levoglucosenone. Reduction of 1,3-diphenylpropan-1-one with reagents obtained by partial neutralization of NaBH4 with hydroxy derivatives of levoglucosenone, on the contrary, predominantly leads to the formation of (R)-1,3-diphenylpropan-1-ol. The addition of AcOH and Bu4NCl to NaBH4 has a positive effect on the optical frequency of the R-alcohol. At the same time, enantioselectivity in the reactions was almost absent upon reduction of 1,3-diphenylpropan-1-one with reagents obtained by partial neutralization of BH3. The best results of enantioselective reduction were shown by unsaturated alcohols: (1S,4S,5R) -6,8-dioxabicyclo[3.2.1]oct-2-en-4-ol and (1S,4S,5R)-4-methyl-6,8-dioxabicyclo[3.2.1]oct-2-en-4-ol, of which (1S,4S,5R)-6,8-dioxabicyclo[3.2.1]oct-2-en-4-ol was the most effective. It is likely that an increase in the enantioselectivity of reactions carried out in the presence of hydroxy derivatives of levoglucosenone is possible by obtaining more bulky chiral ligands, provided that the double bond is retained.


Slovene ◽  
2017 ◽  
Vol 6 (1) ◽  
pp. 413-448
Author(s):  
Elena L. Berezovich ◽  
Valeria S. Kuchko

The article proves the hypothesis of the origin of the Russian colloquial word mazurik as deriving from the name of the Polish ethnographic group mazury ‘Mazurs’—inhabitants of Mazovia (in central and south-eastern Poland) as well as immigrants from this area to other places, mainly in the north-east. This hypothesis had previously been stated in the literature, but it had not been demonstrated rigorously. The authors show that the word mazurik is included in the big semantic word family that is derived from mazur, by studies focused on nationwide usage and through dialects. Using data from the lexical system and from folklore, the linguistic portrait of the Mazurs in the Russian tradition is reconstructed, and it is compared with linguistic stereotypes of the Mazurs in the source language (Polish) and the languages of peoples in close contact with the Mazurs (Ukrainian and Belarusian). The main features of these portraits are the same in these languages, and they create a negative image of the Mazur in the Slavic tradition, making the “Polish” etymological version semantically legitimate. In addition, the authors prove this hypothesis from the point of view of word formation, linguogeography, and sociolinguistic characteristics of the words under consideration. It is noted that the derivatives of the word family derived from mazur are attracted to the lexemes which have similar form and meaning but different origin, in particular, to derivatives of the verb mazatʹ and the words murza and zamurzannyi. The article contains an overview with commentary of hypotheses about the origin of the Russian mazurik existing in Slavic etymological literature.


1942 ◽  
Vol 88 (370) ◽  
pp. 122-126
Author(s):  
F. Reitmann

Derivatives of barbituric acid are in general sedatives, hypnotics and analgesics, but sodium amytal (S.A.) occupies a special position, because of its effect on certain mental and nervous conditions. It produces transient amelioration in catatonic schizophrenia and hypnosis-like conditions in neuroses. The latter is important through the fact that one is able to study hypnosis from a different pharmacological point of view.


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