1-Ethyl-1,4-dihydro-4-oxo-7-(pyridinyl)-3-quinolinecarboxylic acids. I. Synthesis of 3- and 4-(3-aminophenyl)pyridine intermediates

A series of substituted 3- and 4-(3-aminophenyl)pyridines has been prepared as intermediates for the synthesis of some 1-alkyl-1,4-dihydro-4-oxo-7-pyridinyl-3-quinolinecarboxylic acids. The Hantzsch, Hauser and other pyridine syntheses were used. 4-(3-Aminophenyl)pyridine was prepared via 3-(4-pyridinyl)-2-cyclohexen-1-one using the Semmler-Wolff reaction.     

Copper(II)acetate complexes with piperazine, 1-methylpiperazine, 1,4-dimethylpiperazine and their monohydrochlorides

New copper(II) acetate complexes with the saturated diheterocyclic bases (L-L): piperazine, 1-methylpiperazine, and 1,4-dimethylpiperazine and their monohydrochlorides, have been prepared and characterised by physico-chemical and spectroscopic methods. They are magnetically dilute and antiferromagnetic, with stoichiometries of the type Cu(OAc)₂(B)_n(B=L-L or L-LHCl and n=2, 1 or 0.5).     

A Novel One Pot Photochemical Synthesis of Substituted 2-oxo-1,2,2a,11-Tetrahydro-Benzo [3,4-a] Imidazolo [3,4-a] Quinolines

On irradiation with sunlight N-α-cyanoamines (I) undergo a novel cyclisation with the induction of one methylene group from the solvent (methanol) to give new benzoimidazoloquinolines (II) in good yield.     

Microwave‐Assisted Synthesis of Spiro‐Isoxazolidines

Solvent‐free synthesis of spiro‐isoxazolidines (exclusively endo‐diastereoisomers) through [3 + 2] cycloaddition of N‐cyclohexylidene N‐phenyl nitrones with cyclic dipolarophiles under microwave irradiation is described.     

Stretching and collapse of neutral polymer layers under association with ionic surfactants

We provide experimental evidence for stretching and collapse of neutral polymer layers, already adsorbed at an oil-in-water interface, due to its interaction with surfactants. Upon stretching, the first interaction length (2L(0)) follows a power law dependence on surfactant concentration ( proportional, variant C(x)(s), where x approximately 0.5 for cationic surfactants) and collapses in the presence of salt, as a relatively weak power law (C(-y)(s), where y=0.17), in good agreement with brush length decay for polyelectrolyte brushes.     

Estimation of a random coefficient model under linear stochastic constraints

Summary A random coefficient model in which means of random coefficients are subject to a set of linear stochastic constraints is considered and estimators for the means of coefficients are proposed. Their asymptotic properties are presented and some remarks on efficiency are placed.     

One‐pot Regioselective Synthesis of Novel 1‐N‐Methyl‐spiro[2,3′]oxindole‐spiro[3,3″]‐1″‐N‐arylpyrrolidine‐2″,5″‐dione‐4‐arylpyrrolidines through Multicomponent 1,3‐Dipolar Cycloaddition Reaction of Azomethine Ylide

An atom economic and facile synthesis of novel dispiro–oxindole–pyrrolidines has been achieved via a three‐component tandem cycloaddition of azomethine ylide generated in situ from isatin and sarcosine by decarboxylative condensation with N‐aryl‐3‐benzylidene‐pyrrolidine‐2,5‐dione derivatives as dipolarophiles. The salient features of synthetic procedure are characterized by the mild reaction conditions, high yields, high regioselectivity and stereoselectivity, one‐pot procedure, and operational simplicity. This regioselectivity was assumed to be under the influence of π–π stacking interactions between the aromatic rings of azomethine ylide and N‐aryl‐3‐benzylidene‐pyrrolidine‐2,5‐diones that further control the exo–endo selectivity of the reaction 1,3‐dipolar cycloaddition. The regiochemistry and structures of the cycloadducts were determined with spectroscopic data.     

Quantification of Tricyclic and Nontricyclic Antidepressants in Spiked Plasma and Urine Samples Using Microextraction in Packed Syringe and Analysis by LC and GC-MS

In this paper, a highly selective Sudan IV molecularly imprinted polymer was synthesized by surface molecular imprinting technique in combination with a sol?Cgel process using ??-aminopropyl triethoxysilane as functional monomer, tetraethoxysilane as cross-linker and activated silica gel as support material. The imprinted polymer was characterized by FT-IR spectra, scanning electron micrograph and adsorption experiments and it was exhibited good recognition and selective ability, offered a faster rate for the adsorption of Sudan IV. Using the imprinted material as sorbent, a solid-phase extraction coupled with high-performance liquid chromatography method for determination of trace Sudan IV was presented. The detection limit (S/N = 3) was 25.2 ng L^?1, and the RSD for five replicate was 2.86%. With a loading flow rate of 2.5 mL min^?1 for loading 30 mL, an enrichment factor of 104 was achieved. This method was applied for extraction and determination of chilli powder and duck egg samples with good recoveries ranging from 85.3 to 98.1%.     

Study of levels in51Cr through51V (p,nγ) reaction

The low lying levels in⁵¹Cr have been populated by⁵¹V (p, ny)⁵¹Cr reaction. The angular distribution of the ground state electromagnetic transitions from 1165, 1353, 1479 and 1557 keV states have been measured. The results are compared with the Hauser-Feshbach model of the statistical theory of nuclear reactions. The spins for the levels at 1165, 1479 and 1557 keV are shown to be 9/2^?, 11/2^? and 5/2^? respectively.     

Three convenient and novel syntheses of 4-amino-2-arylpyrimidines

4-Amino-2-arylpyrimidines can be prepared conveniently by the reaction of an amidine with the readily available 3-ethoxyacrylonitrile, 2-chloroacrylonitrile or 2-(1-piperidinyl-methyl)acrylonitrile.