Effect of substituents in the dihydropyridine ring on the reactivity of the ester group of 3,5-dialkoxycarbonyl-1,4-dihydropyridines

1982 ◽  
Vol 18 (8) ◽  
pp. 818-823 ◽  
Author(s):  
B. S. Chekavichus ◽  
A. �. Sausin' ◽  
G. Ya. Dubur
Keyword(s):  
Ester Group ◽  
Effect Of Substituents ◽  
Dihydropyridine Ring

scholarly journals MODIFICATION OF OLIGOESTER MALEINATE BY ALKYL ESTER OF N-MALEINIMIDOBENZOIC ACID

2019 ◽  
Vol 62 (12) ◽  
pp. 78-84
Author(s):  
Vladimir A. Danilov ◽  
Oleg A. Kolyamshin ◽  
Nadezhda E. Temnikova ◽  
Oleg V. Stoyanov ◽  
Marina V. Kolpakova
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Unsaturated Polyester ◽  
Ester Group ◽  
Thermomechanical Properties ◽  
Hydrocarbon Radical ◽  
Butyl Ether ◽  
Effect Of Substituents ◽  
Aromatic Group

When using products from unsaturated polyester resins (NPS), often increased requirements for thermal and chemical resistance are raised. Increasing the thermal stability of the PS is possible due to the modification of resins by polymerization compounds, which can copolymerize with both oligoether maleinate and styrene. One of such effective additives is N-phenylmaleinimides. The paper presents the results of modification of unsaturated polyester grade PN-1 UT with alkyl ethers n-maleinimidobenzoic acid. The properties of terpolymers are investigated. The effect of substituents of the aromatic group with N-phenylmaleinimides on the properties of terpolymers was investigated. It is also of interest to study the effect of substituents of the aromatic group in N-phenylmaleinimide on the properties of modified polymers. It is shown that terpolymers due to their maleinimides are superior in strength and thermomechanical properties of the copolymers of oligoestermaleinate and styrene. The increase in the size of the hydrocarbon radical substituents of the aromatic group of maleinimides contributes to the increase of the thermo-and physico-mechanical properties of terpolymers. It is also shown that the glass transition temperature of polymers depends on the content of maleinimides, as well as on the structure of the aromatic group. With an increase in the content of maleinimides (up to 5 wt. %) there is an increase in the glass transition temperature and the beginning of the destructive flow. The greatest increase in glass transition temperature (30 °C) is observed at a content of 3 wt. % butyl ether of n-maleimidobenzoic acid. The increase in the length of the hydrocarbon radical (С5Н11 and С8Н17) of the ester group of n-maleimidobenzoic acid leads to the appearance of a plasticizing effect. Synthesized terpolymers can be recommended as binders in the production of heat-resistant composite materials, in particular, fiberglass.

The Effect of Substituents on the Pyridine Ring in the Diastereoselective Cyclopropanation Reaction of Pyridinium Ylides Bearing an 8-Phenylmenthyl Ester Group.

ChemInform ◽  
2006 ◽  
Vol 37 (29) ◽  
Author(s):  
Satoshi Kojima ◽  
Kouji Fujitomo ◽  
Yoshiaki Itoh ◽  
Kyoko Hiroike ◽  
Masaaki Murakami ◽  
...  
Keyword(s):  
Pyridine Ring ◽  
Ester Group ◽  
Effect Of Substituents ◽  
Pyridinium Ylides

The Effect of Substituents on the Pyridine Ring in the Diastereoselective Cyclopropa- nation Reaction of Pyridinium Ylides Bear- ing an 8-Phenylmenthyl Ester Group

Heterocycles ◽  
2006 ◽  
Vol 67 (2) ◽  
pp. 679 ◽  
Author(s):  
Satoshi Kojima ◽  
Kouji Fujitomo ◽  
Yoshiaki Itoh ◽  
Kyoko Hiroike ◽  
Masaaki Murakami ◽  
...  
Keyword(s):  
Pyridine Ring ◽  
Ester Group ◽  
Effect Of Substituents ◽  
Pyridinium Ylides

The effects controlling the oxygen basicity in alkoxysilanes (RO)nSi(CH3)4-n. The mutual polarizability effect of alkoxy groups attached to silicon

1979 ◽  
Vol 44 (3) ◽  
pp. 750-755 ◽  
Author(s):  
Josef Pola ◽  
Marie Jakoubková ◽  
Václav Chvalovský
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Electronic Effect ◽  
Linear Regression Analysis ◽  
Effect Of Substituents ◽  
Relative Basicity ◽  
Polarizability Effect ◽  
Alkoxy Groups ◽  
Individual Series

Relative basicity of the oxygen in alkoxysilanes (RO)nSi(CH3)3-n having n = 1-4 and various electrondonating and electronwithdrawing groups R measured as Δν(OH) of phenol due to its interaction with these compounds in CCl4 is shown to be chiefly controlled by the electronic effect of substituents R. Linear regression analysis of the Δν(OH) vs n relatioship for individual series (RO)nSi(CH3)4-n suggests the operation of the polarizability effect of RO groups becoming more important with increasing electronwithdrawing nature of R.

Participation of 19-ester groups in the cleavage of 2α,3α- and 5α,6α-steroid epoxides. A case of competition between participation and external nucleophile attack

1979 ◽  
Vol 44 (5) ◽  
pp. 1496-1509 ◽  
Author(s):  
Pavel Kočovský ◽  
Václav Černý
Keyword(s):  
Perchloric Acid ◽  
Hydrobromic Acid ◽  
Ester Group ◽  
Carbonyl Oxygen ◽  
Cyclic Carbonate ◽  
Cyclic Ether ◽  
Normal Reaction ◽  
Neighboring Group ◽  
Ether Oxygen ◽  
The Difference

Acid cleavage of the acetoxy epoxide IIIa with aqueous perchloric acid or hydrobromic acid gave two types of products, i.e. the diol Va or the bromohydrin VIa, and the cyclic ether VIII. The latter compound arises by participation of ether oxygen of the ester group. On reaction with perchloric acid the epoxide IVa gave the diol XIIIa as a product of a normal reaction and the isomeric diol Xa as a product arising by intramolecular participation of the carbonyl oxygen of the 19-acetoxy group. Participation of the 19-ester group is confirmed by the formation of the cyclic carbonate XI when the 19-carbonate IVb is treated analogously. On reaction with hydrobromic acid, the epoxide IVa gave solely the bromohydrin XIVa as a product of the normal reaction course. Discussed is the similarity of these reactions with electrophilic additions to the related 19-acetoxy olefins I and II, the mechanism, the difference in behavior of both epoxides III and IV, the dependence of the product ratio on the nucleophility of the attacking species, and the competition between participation of an ambident neighboring group and an external nucleophile attack.

The structure of 1,2,4,4,6-pentaphenyl-1,4-dihydropyridine

1990 ◽  
Vol 55 (8) ◽  
pp. 2059-2065 ◽  
Author(s):  
Jaroslav Vojtěchovský ◽  
Jindřich Hašek ◽  
Jiří Ječný ◽  
Karel Huml
Keyword(s):  
Title Compound ◽  
Cambridge Structural Database ◽  
Boat Conformation ◽  
Planar Conformation ◽  
Structural Database ◽  
Independent Molecules ◽  
Dihydropyridine Ring

Title compound is triclinic, Mr = 461.60; P1, a = 9.158(1), b = 16.062(3), c = 19.472(3) Å, α = 110.69(1)°, β = 89.70(1)°, γ = 103.17(1)°, V = 2 600(1) Å3, Z = 4, Do = 1.15(3), Dc = 1.179(1) Mg m-3, λ(CuKα) = 1.5418 Å, μ = 0.509 mm-1, F(000) = 976 K, R = 0.040 for 8 059 unique observed reflections. Both symmetrically independent molecules show a different geometry of the 1,4-dihydropyridine ring: either the boat conformation with apexes C(sp3), N and boat angles 14.7(3)° and 10.3(2)° respectively, or the planar conformation. The conformation has been compared with similar dihydropyridines obtained from Cambridge Structural Database.

The Effect of Substituents on the Fluorescent Properties ofPara-Phenylenevinylene

2007 ◽  
Vol 54 (4) ◽  
pp. 853-860 ◽  
Author(s):  
Liang Ding ◽  
Yu-Qi Ding ◽  
Qi-Wen Teng ◽  
Ke Wang
Keyword(s):  
Fluorescent Properties ◽  
Effect Of Substituents
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