VOLUME 5, NO2, JUN 1983

Effects of Inorganic Salts on the Copolymerization of Vinyl and Allyl Monomers Part - V Copolymerization of Styrene and Allyl Alcohol in the Presence of Some Inorganic Salts

The thermal copolymerization of styrene and allyl alcohol in the presence of salts like SrC12, HgC12, CdCl2. ZnCI2, PtCl6 and NiCI2 without using any radical initiator is investigated. The salts increased the rate of copolymerizatio,.. It is due to complex formation of inorganic salts with allyl alcohol which occurs on allylic group of the monomer. The inorganic salts act as chain transfer agent and do not appreciably change the reactivity ratios of the monomers. The copolymerization mechanism is also discussed.read more

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A R KHAN ,S A K LODHI ,

Photolytic Decomposition of Polyhalogenocyclohexanes - A Pathway to the Formation of Substituted Halogenobenzenes

Liquid phalle photohalogenation of benzene/halogenobenzenes give polyhalogeno­c!,clohexane adducts; these adducts are accompanied by substituted products ego mono- and di­halogenobenzenes. Photochemical decomposition of adducts like C6H6Br6 and C6HsClBr6 later gave the same products, ie. bromobenzene, and dibromobenzenes or bromochlorobenzenes. The distrIbution of the dihalogenobenzene isomers was found markedly different from the reported ratio for such isomers in the heterolytic reactions; meta-isomers are found to a significant extent. Evidence adduced suggests an addition-elimination mechanism as a pOlmble pathway to the bromo­substituted arenes in these photochemical reactions. read more

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M I BHANGER ,G H WILLIAMS ,R BOLTON ,

Reactions of 4 or 3 .4-Disubstituted Coumarins With Nucleophilic Reagents

Reactions of 4-<>r 3,4-<lisubstituted-coumarins with nucleophilic reagents have been investigated. The reactions of 4-methoxy-coumarin with nucleophilic reagents were of limited success, however, 4-chloro-3-nitro-coumarin (III) with methanol, ethanol, benzyl alcohol or sodium acetate resulted in the formation of the corresponding 4-substituted-3-nitro-coumarins (Na-<l). 4-Alkoxyor chloro-3-nitro-coumarins (lYa, b or III) with benzyl mercaptan yielded 4-S-benzyl-3-nitro-coumarin (lYe) and 3,4-<li-S-benzyl-coumarin (VIII). Analogous reaction of 3-acetylarnin0-4-methoxy-coumarin with benzyl-mercaptan gave (X). Attempts to cyclise (X) to coumarino-thiazole resulted in the forma­tion of 3-<liacetylarnino derivative (XI). Reactions of the related 4-methoxy-6-methyl-2H-pyran-2-<>ne and its thio-analogue with benzylmercaptan afforded (XIIa) and (XIIb) respectively. read more

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P F G PRAILL ,A W KHAN ,M SIDDIQ ,

Mixed Iron-COpper Binuclear Complexes. Equilibrium Studies of Complexes of Metal-Aminocarboxylate Complexes and Hexacyanoferrate(II)

The equilibrium constants for mixed binuclear complex formation between certain metal-EDTA complexes andhexacyano!errate(ll), ligand, M(II)-EDTA 2- + Fe(CN):- J' [(EDTA) MII-NC-FeII(CN) in aqueous solution have obtained by spectrophotometric measurements. The results are interpreted to obtain the reactivity order of chelating agents and the electron-pair donating ability of cyanometallate. The relative magnitudes of equilibriuin constants are also dis­cussed.read more

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R S MURRAY ,W C E HIGGINSON ,A H KHAN ,

Synthesis of Trans-And Cis-Diphenyl-4-Acrylic Acid

trans-Diphenyl-4-acrylic acid has been synthesized from diphenyl-4-earboxaldehyde which has been prepared by a new route starting from diphenyl. Diphenyl was iust nitrated. The 4-nitro derivative was separated from its 2-isomer and reduced to the amino compound. The iodo derivative of diphenyl was prepared from the amino compound through its diazonium salt and con­verted to the aldehyde through its Grignard reagent. The aldehyde was then condensed with malonic acid to get the trans-diphenyl-4-acrylic acid. The dibromide of the ethyl ester of this acid was then prepared and subjected to dehydrobromination to get diphenyl-4-propiolic acid which was reduced catalytically to give cis-diphenyl-4-acrylic acid.read more

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S A FASEEH ,M YOUNAS ,S M YOUNAS ,

Structure of Ethy.lenediaminetetra-Acetate Complex of Iron(III) In Aqueous Solution

The stability constants for mixed binuclear complex formation in aqueous solution between Iron(IlI}-EDT A complex and various ligands, thiocyanate and hexacyanofenate(lI), have been obtained from spectrophotometric measurements. The results can be interpreted to obtain the evidence that the Iron(I1I}-EDTA complex is predominantly six-coordinated and hexadentate in solution.read more

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W C E HIGGINSON ,A H KHAN ,

Studies in the Chemical Constituents of the Fresh Berries of Solanum xanthocarpum Schrad. And Wendle

Chemical investigations of the fresh, undried, ripe and unripe berries of Solanum xan­thocarpum collected from the arid areas of Pakistan have led to the isolation of three glyco bases: solasonine, solamargine and solasurine, apart from an apparently partially hydrolysed glyco base. The solasodine content was noted as 0.75% and 1.7% (on dry weight basis) in ripe and umipe berries, respectively. From the non-alkaloidal constituents, the galactoside of {j-sitosterol and two phenolic substances identified as the methyl ester of 3,4-dihydroxycinnamic acid (methyl caffeate) and 3,4­dihydroxycinnamic acid (caffeic acid) have been isolated. read more

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B S SIDDIQUI ,S SIDDIQUI ,S FAIZI ,

Synthesis of Acetylenic Alcohols by Base Catalyzed j3-Elimination of 3-ehloro-4,S-Dihydrofuran or S-ehloro-3,4-Dipydro-2H-Pyran and their Alkyl Derivatives as Well as Alkylation of w -Hydroxy-Alk-l- Ynes

Acetylenic alcohols were synthesised from 3-chlor0-4,5~ihydrofuran and its 2-alkyl derivatives, or 5-ch1oro-3,4~ihydro-2Hpyraa and its 6-alkyl derivatives via base catalyzed j3-elimina­tion using sodium metal in THF. Also alkylation followed by hydrolysis of the dilithium salt of w-hydroxy-alk-I-ynes in THF/HMPT leads to the corresponding acetylenic alcohols.read more

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M A HASSAN ,

Synthesis and Reactions of 4-[(4-0xo -4H-l-Benzopyran-2-yl) Methylene] -2-Phenyl-S (4H)-Oxazolone

Azlactone I reacted with hydrazines and some amino compounds gave the corres­ponding hydrazides and amides. Treatment of I with sodium hydroxide or Sodium acetate gave 3 a or b respectively. Also I reacted with Grignard reagents to give 4a-e. COnIJgUIational assignment of the new compounds was based on elemental analysis, IR and NMR spectrosopic evidences. read more

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M A HASSAN ,M EL BORAI ,S EL NAGDY ,

Study of Ionic Conductivity of Lanthanum Oxychloride

The ionic conductivity of lanthanum oxychloride has been measured by using the method of plotting graphs of impedance in the plane complex. The ionic conductivity measurements were made for the temperature limits (300 - l400)oC. The determined·activation energy at low temperature agrees with that measured for PbCl2 and SrCl2 as given respectively,1,2,3, while the value at high temperature shows a slight agree,ent with measurements made on Th02- Y01.5 15% , La203 -caO and La203 - srO of Hammou .and VanbaeliDghem.read more

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A HAMMOU ,M A AL RIKABI ,