VOLUME 7, NO1, MAR 1985

INFRARED STUDY OF KETO-ENOL EQUILIBRIUM OF ACETYLACETONE, BENZOYLACETONE AND DIBENZOYLMETHANE IN VARIOUS ORGANIC SOLVENTS

The keto-enol equilibrium of acetylacetone, benzoylacetone and dibenzoylmethane in various polar and non-polar solvents have been calculated using IR technique. Substitution of methyl group by phenyl group in acetylacetone shifts the equilibrium towards the enol form due to increase of resonance energy of the enol form and therefore dibenzoylmethane is completely enolized, the enol content increases as the polarity of the solvent decrease. The band at 1695 cm-1 in the spectrum of acetylacetone relatively various with solute concentration in non-polar solvent. This band attributes to the presence of small amount of non-chelated enol molecules which are absent in the other two compounds.read more

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N A ABOOD ,A F AJAM ,

INVESTIGATION OF PHOSPHOLIPASE B TYPE ACTIVITY IN MORINGA OLEIFERA SEEDS

Lipolytic enzyme activity was demonstrated in Moringa oleifera seeds by the use of lecithin as a substrate in aqueous and non aqueous system of assay. Comparatively high lipolytic activity in aqueous system suggested presence of a souble enzyme.  Under both assay system the complete deacylation of ovolecithin resulted in water soluble glyceryl phosphorylcholine and the free fatty acid and no accumulation of monoacylphosphatidyl choline was observed. read more

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M UMAR DAHOT ,A R MEMON ,

CHELATING BEHAVIOUR OF SUBSTITUTED 3-ARYLHYDRAZO-PENTANE-2,4-DIONE PART VIII THE STABILITIES OF COMPLEXES OF LANTHANIDE IONS WITH 2-,3-,4-AND 2-SULPHONIC (4-METHYL) PHENYLHYDRAZO-PENTANE-2,4-DIONE LIGANDS

The stability constants have been determined for the reaction products of 2-,3-,4-, and 2-sulphonic (4-methyl) phenylhydrazone pentan-2, 4-dione (2SPHA, 3-SPHA, 4-SPHA and 2-S (4-Me)PHA) ligands with tervalent lanthamide ions. The measurements have been made at constant temperature 30oC and ionic strength 0.1 M in aqueous medium. Plotting log B2 (overall) stability constant) against the atomic number of the lanthanide elements showed linear relationship from La to Eu with change in stability of 0.12, 0.24, 0.26 and 0.1 for 2-, 3-, 4-and 2-S(4-Me) PHA ligands respectively. After Gd, the stability remains nearly constant. The effect of substitution of sulphonic groups was discussed. The relation between log B2 and the pK's values of the organic ligands was also investigated.read more

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A A RAMADAN ,M S ABDL-MOEZ ,A M EL-ATRASH ,B A SHETARY ,G A EL-INANY ,

STUDIES ON SYNTHETIC, ANALYTICAL, SPECTRAL AND MAGNETIC PROPERTIES OF OXOVANADIUM (V) COMPLEXES OF SCHIFF BASES

Reactions of oxovanadium triisopropoxide with nitrogen donor ligands under controlled and anhydrous conditions have yielded two interesting  series of oxovanadium (V) complexes of the type: (i) VO (OPri)2(SB) and VO(OPri)(SB)2 and (ii) VO(OPri)(S'B') and (VO)2(S'B')3 (where SBH and S'B'H2 represent the monofunctional bidentate and bifunctional tridentate Schiff base molecules, respectively). The alcoholysis reactions further give VO(OBut)2 (SB), VO(OBut)(SB)2 and VO(OBut)(S'B') type of derivatives in presence of excess of t-butanol. All the resulting complexes are coloured solids or semisolids and behave as non-electrolytes in anhydrous DMF. The IR, UV, 1H NMR and magnetic measurements have been discussed in support of the proposed structures. read more

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J P TANDON ,R V SINGH ,M N MOOKERJEE ,

CHEMICAL STUDIES ON ZIZYPHUS RUGOSA Lam.

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A H SHSH ,V B PANDEY ,R L KHOSA ,J P SINGH ,

ALKALOIDE AUS RHAMNACEEN, 36*): 1H-NMR-SPEKTROSKOPISCHE UNTERSUCHUNGEN AND NUMMULARIN-B

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A H SHSH ,R WAGNER ,R TSCHESCHE ,V B PANDEY ,G A MIANA ,

SYNTHESIS OF SOME 3-SUBSTITUTED 6-(a-STYRYL) PYRIDAZINE DERIVATIVES

3-Chloro-6-(alpha)-styryl)pyridazines (1) react with primary amines to give 3-substituted-amino-6-(alpha) styryl) pyridazines (2a-d) while they react with alcoholic thiourea to give 3-mercapto-6-(alpha) styrl) pyridazines (4). The latter compounds were also prepared by the action of phosphorus pentasulphide on 6-(alpha)-styryl) pyridazin-3 (2H)-ones (6). The reaction of 4 with alkyl iodides and acrylonitrile is also discussed. read more

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N A SHAMS ,A M.A EL KHAMRY ,O E MUSTAFA ,M F ISMAIL ,

REACTIONS OF SOME 2(1H)-PYRIDONES SYNTHESIZED FROM 3,4-METHYLENE-DIOXYBENZAL AND 4-NITROBENZAL-P-ISOPROPYLACETOPHENONE

Benzalacetophenone derivatives (1) react with ethyl cyanoacetate in the presence of ammonium acetate at 120o to give a mixture of 2(1H) pyridine derivatives (2) and ethyl nicotinate derivatives (3). The behaviour of pyridine derivatives (2) towards electrophilic reagents e.g., dimethyl sulphate and ethyl chloroacetate, and nucleophilic reagents e.g., phosphorus oxychloride has been investigated. On the other hand, the behaviour of ethyl nicotinate derivative (3a) towards nitrogen and oxygen nucleophiles has also been discussed. read more

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M A SAYED ,A A SHEHATA ,M M MOHAMED ,M A EL-HASHASH ,

2,3-DIHYDRO-2-METHYL-4H,5H-PYRANO(3,4-B) PYRAN-4, 5-DIONES FROM THE REACTION OF DEHYDROACETIC ACID AND ALDEHYDES

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A WAHEED KHAN ,M SIDDIQ ,P F PRAILL ,

A FACILE CONVERSION OF (Alpha)-KETO ACID ANILS TO ANILIDES

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A AHMAD ,I ALAM ,