Pinacol-Pinacolone Rearrangement of 1, 2-Di-(p-methoxyphenyl)-ethane-1, 2-diol and Bis-(4-methoxyphenyl)-acetaldehyde in Acid Media

1, 2-Di-(p-methoxyphenyl)-ethane-1, 2-diol gave in acid media bis-(4-methoxy-phenyl)-acetaldehyde, 4-4′-dimethoxy-deoxybenzoin, and 1, 2-di-(p-methoxyphenyl)-ethylene oxide; their respective yields being influenced by at least 3 factors: (i) the acid, (ii) its concentration, and (iii) the reaction period. Bis-(4-methoxyphenyl)-acetaldehyde rearranged to the deoxybenzoin in boiling sulfuric (50%) or phosphoric (75%) acids (w/w), and to two isomeric 1, 2-diacetoxy-1, 2-di-(p-methoxyphenyl) ethanes when it was heated with acetic anhydride. The mechanisms of these reactions are discussed.     

Preparation of Diazo Phenyl Sulfides. Kinetics and Mechanism of the Diazo Coupling Reaction of p-Nitrobenzenediazo Phenyl Sulfide with β-Naphthol under Various Conditions

Aryldiazophenyl sulfides prepared from diazotised arylamines and thiophenol at controlled pH, are coupled with β-naphthol yielding the corresponding azo dye. A kinetic study of the diazo coupling reaction of p-nitrobenzenediazo phenyl sulfide with β-naphthol under various conditions revealed that the reaction is of first order kinetics with respect to the diazo phenyl sulfide, and that the rate of coupling measured colorimetrically is influenced by the hydrogen ion concentration and by the ionising power of the medium.     

Gravimetric and Colorimetric Determinations of Copper,Cobalt, Zinc and Mercury with 1-(2-Methylindole-3-Acetyl)-4-Arylthiosemicarbazide

1-(2-Methylindole-3-acetyl)4-arylthiosemicarbazides have been prepared and were used as reagents for gravimetric and colorimetric determinations of copper, cobalt, zinc and mercury. The synthesis of the same metal complexes of these thiosemicarbazides as a potential biological derivatives was also described.     

Characterization and elimination of the interfering effects of foreign species in the atomic-absorption determination of iron

The inhibition-release titration method has been used to study interference effects in flame atomic-absorption determination of iron. Interferences from anions, cations and complexing agents with the atomic-absorption of iron when a stoichiometric air-acetylene flame is used, can be obviated by a preliminary treatment of the sample solution with sulphosalicylic acid to convert the iron into the same complex before aspiration, thus giving a constant environment for the iron in the flame processes.     

Comparative Study of Some Methods for the Determination of the Analgesic Anti-Inflammatory Compound “IS4”: 4-(Anisylideneamino) Antipyrine

A comparative study of some quantitative methods has been undertaken. Chemical and colorimetric procedures have been developed for the determination of IS₄: 4-(anisylideneamino) antipyrine. The non-aqueous titration and the nitritometric techniques were used. The formation of colored azo dye derivatives through diazotization and coupling with phenolic and amine reagents has been the basis of the colorimetric determination. Statistical analysis of the results has shown that a good agreement of the results has been found on applying the proposed methods to 4-aminoantipyrine.     

Microdetermination of Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd, Hg, Pb, Bi and U in inorganic and organometallic compounds with morpholinium morpholine-N-dithiocarboxylate

The chelates of morpholinium morpholine-N-dithiocarboxylate with manganese(II), iron(II), iron(III), cobalt(II), nickel, copper(II), zinc, silver, cadmium, mercury(II), lead, bismuth and uranium(VI) have been prepared and their compositions elucidated. Simple, accurate and relatively rapid procedures for the gravimetric and titrimetric microdetermination of these metals in inorganic and organometallic compounds are presented.     

Halogenation of Xanthenyl and Thioxanthenylallenes

Reactions of acids with vinylidenexanthenes (or thioxanthenes) 1 and 9-methoxy-9-vinylxanthenes (or thioxanthenes) 8 give xanthene- (or thioxanthene-) 9-spiro-1′-indenes 7 . With bromine or sulfuryl chloride they give the corresponding 2′-halogenoxanthene- (or thioxanthene-)9-spiro-1′-indenes 5 . Formation of such derivatives depends on preferential attack of the reagents on allenes 1 to give initially xanthylium (or thioxanthylium) ions 3 which cyclize. One π bond of the allenes 1 can be selectively reduced in acid media. Chemical and spectral evidence for these routes are presented.     

Photometric microdetermination of acetyl groups in organic compounds

A method for the microdetermination of acetyl groups is described which combines features of the known transesterification and the hydroxamate methods. All acetyl groups attached to oxygen or nitrogen are converted to methyl acetate which is distilled off and determined photometrically as the iron complex of the acethydroxamic acid. A slightly modified technique permits the selective determination of acetyl groups in the presence of formyl groups.     

Polarographic behaviour of some p-nitrophenyl-diazo-aryl sulphides in aqueous buffered media

The polarographic behaviour of some p-nitrophenyl-diazo-aryl sulphides in 40% ethanolic aqueous buffers is reported and discussed. The mechanism of electrode processes corresponding to the observed cathodic waves is proposed and clarified by means of model compounds and identification of controlled potential electrolysis products.     

Development of an Analytical Proton Magnetic Resonance (PMR) Spectroscopic Method for the Determination of Etilefrine in Bulk and Pharmaceutical Forms

An analytical proton magnetic resonance (PMR) spectroscopic method was developed for the determination of etilefrine hydrochloride [943–17–9] in bulk, I, tablets, II, drops, III, and injectables, IV,. The method is advantageous over those in the literature offering a fast, simple, specific, and accurate procedure.