Knoevenagel condensation of 2-carbethoxycyclohexanone and malononitrile: Synthesis of 4-cyano-3-ethoxy-1-hydroxy-5,6,7,8-tetrahydroisoquinoline,an isomer of the abnormal product

The structure of the abnormal product 1a formed in the Knoevenagel condensation of 2-carbethoxycyclohexanone and malononitrile has been further confirmed. Oxidation of the tetrahydroisoquinoline 3b using Na₂Cr₂O-AcOH-H₂SO₄ gave the keto isoquinoline 3d and the isoquinoline-1-carboxylic acid 5a. The acid chloride of 5a was condensed with diethyl ethoxymagnesiomalonate to afford after decarbethoxylation the methyl ketone 5d which on Baeyer-Villiger oxidation gave a mixture of the acetate 1g and the title compound 1b. The unambiguous synthesis of 1b confirms the structure assigned earlier to the title compound also formed during the partial hydrolysis of the diethoxy compound 1c. Condensation of 2-acetylcyclohexane-1,3-dione with malononitrile gave the quinoline derivative 4c which on ethylation yielded the ketoquinoline 4d. The present studies have confirmed that the quinoline compound 4a is also formed in the condensation of 2-acetylcyclohexanone and cyanoacetamide.     

On the formation of shock and soliton in a dense quantum dusty plasma with cylindrical geometry

Excitation of nonlinear waves in a quantum dusty plasma with various effects is analyzed when the geometry is cylindrical.This introduces the effect of finite boundary conditions on the solitary waves so generated. it is observed that the nonlinear equation deduced is cylindrical KP–Burger type leading to the generation of Shock Wave. Different situations which arises in various parameter regions are considered separately and the form of the nonlinear excitations are obtained explicitly.     

Optimally Decomposing Coverings with Translates of a Convex Polygon

We show that any k-fold covering using translates of an arbitrary convex polygon can be decomposed into Ω(k) covers. Such a decomposition can be computed using an efficient (polynomial-time) algorithm.     

Amide catalysed facile isomerization of 5,6-dihydroisoquinolines: synthesis of stable 1,2-dihydroisoquinolines.

Stable 1,2-dihydroisoquinolines have been synthesized by an amide catalysed novel isomerization reaction of 5,6-dihydroisoquinolines.     

Fluxes in "free" and total zinc are essential for progression of intraerythrocytic stages of Plasmodium falciparum

Dynamic fluxes in the concentration of ions and small molecules are fundamental features of cell signaling, differentiation, and development. Similar roles for fluxes in transition metal concentrations are less well established. Here, we show that massive zinc fluxes are essential in the infection cycle of an intracellular eukaryotic parasite. Using single-cell quantitative imaging, we show that growth of the blood-stage Plasmodium falciparum parasite requires acquisition of 30 million zinc atoms per erythrocyte before host cell rupture, corresponding to a 400% increase in total zinc concentration. Zinc accumulates in a freely available form in parasitophorous compartments outside the food vacuole, including mitochondria. Restriction of zinc availability via small molecule treatment causes a drop in mitochondrial membrane potential and severely inhibits parasite growth. Thus, extraordinary zinc acquisition and trafficking are essential for parasite development.     

Molecular rearrangement of photoparthenin by BF3-etherate-acetic acid complex: X-ray crystal structure of a novel product

The structure of a novel compound,Iupac name: bicyclo [2.4.0]-octa-1,3-dimethyl-2,3-pentan-9-methylene-8, 10-butan-diolide, which resulted on treatment of photoparthenin with BF₃-etherate acetic acid, has been established uniquely by X-ray crystallography. C₁₅H₁₈O₄ is orthorhombic, space group P2₁2₁2₁, with the cell dimensionsa=8.444(1),b=9.964(2),c=16.239(2) Å,V=1366.3(2) ų,Z=4,M _r =262.3,D _o=1.29,D _x=1.28 g cm^–3, F(000)=560,T=293K,R=0.065 for 818 observed reflections. -lactone ring has a skew-boat, -lactone ring has an envelope, and the remaining six-membered ring has a distorted chair conformation. The four-membered ring is nonplanar. There are two intramolecular and one intermolecular short C-HO interactions 2.819, 2.834, and 3.259 Å, respectively, which stabilize the crystal structure.N.C.L. Communication No. 4583.     

Coefficient of volume expansion and thermoacoustic parameters in certain alkoxy benzylidene butylanilines — IB

Using the coefficient of volume expansion certain thermoacoustic parameters like isobaric (K), isothermal (K″), isochoric (K″) acoustic parameters, free volume (V_a/V) and two new dimensionless acoustic parameters A* and B* are estimated in certain alkoxy benzylidene butylanilines, in their isotropic- and mesophases as well as at and in the immediate vicinity of the phase transition temperatures following the method which was suggested by Sharma, for non-mesomorphic systems.