JSCS Vol 66, No. 1

Adobe Acrobat version
These articles were created using Adobe Acrobat and were compressed using WinZip
To download the latest
Adobe Acrobat viewer click here
To download the text of the whole issue click here (1.15 MB - WinZip file)
To download the latest
WinZip version click here

Impresum (89 KB - WinZip file)Content of Vol 66, No. 1 (492 KB - pdf file)Instruction for authors (37 KB - pdf file)

J. Serb. Chem. Soc. 66(1) 1–8 (2001)
UDC 547.424.1:547.737
JSCS – 2824
Original scientific paper

Nucleophilic opening of the 3,5-anhydro ring in 1,2-O-cyclohexylidene-a-D-xylofuranose

PAVLE HADZIC, NADA VUKOJEVIC*, MIRJANA POPSAVIN and JANOS CANADI

Institute of Chemistry, Faculty of Science, University of Novi Sad, Trg Dositeja Obradovica 3, YU-21000 Novi Sad and
*Department of Organic Chemistry, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, YU-11000 Belgrade, Yugoslavia

(Received 23 May 2000)
The reactivity of the oxetane ring in 3,5-anhydro-1,2-O-cyclohexylidene-a-D-xylofuranose (1) was exemplified by its regiospecific nucleophilic opening. The action of  concentrated hydrobromic or hydroiodic acid on 1 resulted in the exclusive formation of the 5-deoxy-5-halo derivatives, while the action of acetyl chloride or acetyl bromide yielded the corresponding 3-O-acetyl-5-deoxy-5-halo derivatives in 70 – 90 % yield. Under strongly acidic reaction conditions, the protection of the cyclohexylidene acetal function remained intact.
Keywords: oxetane, sulfonyl esters, nucleophilic ring opening, D-xylofuranose derivatives.
To download this article click here (95 KB pdf file)

J. Serb. Chem. Soc. 66(1) 9–16 (2001)
UDC 547.427.2:547.388.1
JSCS – 2825
Original scientific paper

Synthesis and reactivity of some Mannich bases. VIII. Studies on several Mannich bases derived from ortho-hidroxyacetophenones and their conversion into oximino derivatives

EUGENIA COMANITA, GHEORGHE ROMAN*, IRINA POPOVICI** and BOGDAN COMANITA***

Department of Organic Chemistry, "Gh. Asachi" Technical University, 71A D. Mangeron Blvd., RO-6600 Iasi, Romania,
*Chemistry Department, "Transilvania" University, 29 Eroilor Blvd., RO-2200 Brasov, Romania,
**"Gr. T. Popa" University of Medicine and Pharmacy, 16 University St., RO-6600 Iasi, Romania and
***National Research Council of Canada, Institute for Chemical Process and Environmental Technology, Montreal Road Campus, KIA 0R6, Ottawa, Canada

(Received 22 December 1999)
The synthesis of several Mannich bases resulting from the reaction of 2-hydroxy-4-methylacetophenone with paraformaldehyde and secondary amines is reported. Another series of products was obtained from N,N-dimethyl substituted Mannich bases by replacing the amino group with pyrrolidine. Most of the Mannich bases were transformed into oximes by treatment with hydroxylamine hydrochloride in 10 % NaOH.
Keywords: ortho-phenolic ketones, Mannich bases, amine exchange reaction, Mannich bases oximes.
To download this article click here (96 KB pdf file)

J. Serb. Chem. Soc. 66(1)17–21(2001)
UDC 547.622:547.78:547.466
JSCS – 2826
Original scientific paper

Sulfur containing activated hydantions. Synthesis and screening some novel benzylidenehydantoins amino acids derivatives

RAGAB A. EL-SAYED

Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt

(Received 19 September 1999, revised 7 May 2000)
5-Benzylidenehydantoin reacts with chlorosulfonic acid to give the corresponding p-sulfonyl chloride 1. Condensation with nucleophiles gives amino acid derivatives 2–7. Coupling reactions of some amino acid derivatives (2–6) with amino acid methyl ester hydrochloride in THF-Et3N medium using the dicyclohexylcarbodiimide method (DCC) furnish the desired dipeptide methyl esters 8–12. The spectral data of the synthesized compounds are briefly discussed.
Keywords: benzylidenehydantoins amino acids, dipeptide derivatives.
To download this article click here (65 KB pdf file)

J. Serb. Chem. Soc. 66(1) 23–26 (2001)
UDC 615.35:547.388.4:
JSCS–2827
Note

N O T E
Synthesis and chemical behaviour of 17a-butyl-3b,17b-dihydroxy-16-oximino-5-androstene

SRDJAN STOJANOVIC, DORA MOLNΑR GΑBOR, LJUBICA MEDIC-MIJACEVIC, MARIJA SAKAC and KATARINA PENOV GASI

Institute of Chemistry, Faculty of Science, Trg Dositeja Obradovica 3, YU-21000 Novi Sad, Yugoslavia

(Received 4 July, revised 13 October 2000)
Starting from 3b-hydroxy-16-oximino-5-androsten-17-one (1), the recently synthesized 16-oximino-17b-hydroxy-17a-butyl derivative 2 gave by the Beckmann fragmentation reaction with titanium(III) chloride or p-toluenesulphonyl chloride the corresponding D-seco derivative 3. However, using acetic anhydride, in addition to the 3b-acetoxy D-seco derivative 4, the 17-aza D-homo derivative 5 was obtained. The structure of compound   was proposed on the basis of NMR-spectroscopy.
Keywords: 17-aza-D-homo derivatives of androstene, Beckmann fragmentation.
To download this article click here (67 KB pdf file)

J. Serb. Chem. Soc. 66(1) 27–37 (2001)
UDC 547..551:542.9:541.138
JSCS – 2828
Original scientific paper

Electrochemical synthesis of poly(2-methyl aniline): electrochemical and spectroscopic characterization

ALEKSANDRA BUZAROVSKA, IRENA ARSOVA and LJUBOMIR ARSOV

Faculty of Technology and Metallurgy, University “St. Cyril and Methodius”, 91000 Skopje, Macedonia

(Received 21 June, revised 31 October 2000)
Poly(2-methyl aniline) or poly(ortho-toluidine), as ring substituted derivative of aniline, has been synthesized electrochemically in various concentrations of H2SO4 and HCl, and then characterized by cyclic voltammetry, as well as by impedance and Raman spectroscopy. The cyclic voltammograms of poly(o-toluidine) and poly(aniline) show that the electrochemical polymerization of these two polymers proceeds by almost identical mechanisms. The Raman spectroscopical measurements suggest that the redox reactions of poly(aniline) and poly(o-toluidine) are similar in the potential range between –0.2 and 0.7 V vs. SCE. The impedance measurements showed that the conductivity of poly(o-toluidine) is an order of magnitude lower than that of the corresponding poly(aniline) form.
Keywords: poly(2-methyl aniline), electropolymerization, cyclic voltammetry, Raman spectroscopy.
To download this article click here (110 KB pdf file)

J. Serb. Chem. Soc. 66(1) 39–44 (2001)
UDC 549.284–002.4:543.544
JSCS – 2829
Original scientific paper

Thin-layer chromatography of several antihypertensive drugs from the group of angiotensin converting enzyme inhibitors

MIRJANA B. ALEKSIC, DANICA G. AGBABA, RADA M. BAOSIC*, DUSANKA M. MILOJKOVIC-OPSENICA* and ZIVOSLAV LJ. TESIC*

Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, P. O. Box 146, YU-11001 Belgrade and
*Faculty of Chemistry, University of Belgrade, Studentski trg 16, P. O. Box 158, YU-11001 Belgrade, Yugoslavia

(Received 3 April, revised 26 June 2000)
A rapid and simple method for the chromatographic separation of pharmacologically active components contained in some antihypertensive drugs has been developed employing thin-layers of silica gel and polyacrylonitrile sorbent (PANS). The active compounds of Captopril – (S)-1-(3-mercapto-2-methyl-1-oxopropyl)-L-proline, Enalapril – (S)-1-[N- [1-(ethoxycarbonyl)-3-phenylpropyl]-L-alanyl]-L-proline, Lisinopril – (S) -1-[N2-(carboxy-3-phenylpropyl)-L-lysyl]-L-proline, Quinapril – [3S-[2[R*(R*)],3R*]], -2- [2-[[1(- etho- xycarbonyl)-3-phenylpropyl]amino]-1-oxopropyl]-1,2,3,4-tetrahydro-3-iso-quinoline-carboxylic acid, Ramipril – [2S-[1[R*(R*)],2a3ab,6ab]]-1-[2[[1-(ethoxycarbo- nyl)-3-phenylpropyl]amino]-1-oxopropyl]octahydrocyclopenta[b]-pyrole-2-carboxylic acid and Cilazapril – [1S-[1a,9a (R*)]]- 9-[[1-(ethoxycarbonyl)-3-phenylpropyl]amino] octahydro-10-oxo-6H-pyridazino[1,2-a][1,2] diazepine-1-carboxylic acid, were successfully separated by the presented procedures. For their chromatographic separation on silica gel sixteen and on PANS thirteen solvents were used.
Keywords: thin-layer chromatography, silica gel, polyacrylonitrile sorbent, antihypertensive drugs, angiotensin converting enzyme inhibitors.
To download this article click here (79 KB pdf file)

J. Serb. Chem. Soc. 66(1)45–52(2001)
UDC 549.282:549.283:543.062:620.11
JSCS – 2830
Original scientific paper

The determination of the content of gold and silver in geological samples

N. PETROVIC, D. BUDJELAN, S. COKIC and B. NESIC

Copper Institute, Zeleni bulevar 35, YU-19210 Bor, Yugoslavia

(Received 5 March, revised 15 September 2000)
A method has been elaborated for the determination of the content of gold and silver in geological samples by atomic absorption spectrophotometry (AAS) in combination with the fire assay method. The weight of sample used for analysis was 10 g. Sulphur present as sulphide, which is an undesirable element in smelting, was removed by the addition of iron to the charge. The sample was smelted with fluxes and lead oxide to replace the silver and gold by lead and to transfer non-precious elements to slag. Lead was separated from precious metals by cupellation. The separated silver and gold alloy was dissolved with aqua regia with addition of hydrochloric acid in excess. Silver and gold were determined from the same solution. For determination of the silver content, the AAS method with an air-acetylene flame was used. Gold was determined in a graphite furnace with the addition of a matrix modifier in an argon current, at an atomization temperature of t = 2200°C. The lower determination limit for silver was 0.05 g/t and for gold 0.005 g/t. The results of the analysis for silver and gold obtained with the proposed method showed good agreement with the results of the analysis of the same samples with the fire assay method.
Keywords: geological sample, gold, silver, fire assay, atomic absorption, air-acetylene flame, graphite furnace.
To download this article click here (73 KB pdf file)

J. Serb. Chem. Soc. 66(1)53–64(2001)
UDC 541.124:541.123.2
JSCS – 2831
Original scientific paper

Hydrodynamic characteristics of a two-phase gas-liquid flow upward through a fixed bed of spherical particles

SNEZANA M. SERBULA and VELIZAR D. STANKOVIC

Technical Faculty Bor, University of Belgrade, P. O. Box 50, YU-19210 Bor, Yugoslavia

(Received 17 January, revised 31 July 2000)
The influence of an electrochemically generated gas phase on the hydrodynamic characteristics of a three-phase system has been examined. The two-phase fluid, (gas-liquid), in which the liquid phase is the continuous one, flows through a packed bed with glass spheres. The influence of the liquid velocity was examined, as well as the gas velocity and particle diameter on the pressure drop through the fixed bed. It was found that with increasing liquid velocity (wl = 0.0162–0.03 m/s), the relative pressure drop decreases through the fixed bed. With increasing current density, the pressure drop increases, since greater gas quantities stay behind in the fixed bed. Besides, it was found that with decreasing diameter of the glass particles, the relative pressure drop also decreases. The relationship betweeen the experimentally obtained friction factor and the Reynolds number was established.
Keywords: two-phase flow, fixed bed, water electrolysis, pressure drop, fluidization.
To download this article click here (112 KB pdf file)

Society Home Page
Contents of this Vol.
Journal Home Page

Copyright & copy; SHD 2001.
Last Updated January 16, 2001.
For more information contact: SHD@elab.tmf.bg.ac.yu