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eng Thermal analysis of N-carbamoyl benzotriazole derivatives
KOS, IVAN; WEITNER, TIN; FLINČEC GRGAC, SANDRA; JABLAN, JASNA
Acta Pharmaceutica Vol. 65, No. 2, 2015
Thermal properties of N-carbamoyl benzotriazole derivatives and N,N',N''-tribenzyloxyisocyanuric acid were investigated using thermogravimetric analysis and differential scanning calorimetry. The results revealed a difference between structural analogs of N-carbamoyl benzotriazole derivatives. They seem to be in agreement with the previously proposed formation of N,N',N''-tribenzyloxyisocyanuric acid from 1-(N-benzyloxycarbamoyl) benzotriazole, via an intermediary N-benzyloxyisocyanate acid, during heating. Substantially different thermal prope...
Hrčak ID: 128996


eng Benzotriazole as a Synthetic Auxiliary
Zorc, Branka; Rajić Džolić, Zrinka; Butula, Ivan
Croatica Chemica Acta Vol. 85, No. 4, 2012
Benzotriazole is a very useful synthetic auxiliary with versatile applications in organic chemis¬try. We have used benzotriazole in the synthesis of various heterocyclic compounds (benzoxazine, quinazoline, triazinetrione, hydantoin, oxadiazine and diazepane derivatives), amino acid derivatives, car¬bamates, ureas, semicarbazides, carbazides, sulfonylureas, sulfonylcarbazides, hydantoic acids, non-steroidal antiinflammatory drug (NSAID) and primaquine derivatives, polymer-drug and thiomer-drug conjugates. The results have been published in more...
Hrčak ID: 94472


eng Electrochemical and Spectroscopic Study of Benzotriazole Films Formed on Copper, Copper-zinc Alloys and Zinc in Chloride Solution
Milošev, I.; Kosec, T.
The formation of protective layers on copper, zinc and copper-zinc (Cu-10Zn and Cu-40Zn) alloys at open circuit potential in aerated, near neutral 0.5 M NaCl solution containing benzotriazole (BTA) was studied using potentiodynamic measurements, electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). The addition of benzotriazole affects the dissolution of the materials investigated. Benzotriazole, generally known as an inhibitor of copper corrosion, is also shown to be an efficient inhibitor for copper-zinc al...
Hrčak ID: 34605


eng A convenient synthesis of new NSAID esters containing amino acid, urea and amide moieties
PERKOVIĆ, IVANA; RAJIĆ DŽOLIĆ, ZRINKA; ZORC, BRANKA
Acta Pharmaceutica Vol. 63, No. 3, 2013
A convenient synthetic method for the preparation of novel NSAID twin esters 6a-i containing amino acid residue, urea and amide moieties has been developed. The synthetic pathway applied for the preparation of target compounds and key intermediates 1-benzotriazolecarboxylic acid chloride (1), NSAID benzotriazolides 2a-c and N-(1-benzotriazolecarbonyl)-amino acids 3a-d involved benzotriazole as a synthetic auxiliary. The final preparation step of esters 6a-i included the solvent-free reaction of compounds 2a-c with amino acid derivatives 5a-g, b...
Hrčak ID: 102049


eng The Novel Ketoprofenamides: Synthesis and Spectroscopic Characterization
Zovko, Marijana; Zorc, Branka; Jadrijević-Mladar Takač, Milena; Metelko, Biserka; Novak, Predrag
Croatica Chemica Acta Vol. 76, No. 4, 2003
Synthesis of a series of new ketoprofenamides (<b>3a-h</b>) is described. Amide formation was achieved by aminolysis of ketoprofen benzotriazolide (<b>2</b>) with various amines: primary, secondary, hydroxylamine and amino acid &beta;-alanine. The structures of synthesized compounds were characterized by means of IR, <sup>1</sup>H and <sup>13</sup>C NMR spectroscopies and elemental analysis. The synthesized compounds are potential prodrugs of a well-known NSAID ketoprofen.
Hrčak ID: 103196


eng Novel Ureidoamides Derived From Amino Acids: Synthesis and Preliminary Biological Screening
Perković, Ivana; Butula, Ivan; Rajić, Zrinka; Hadjipavlou-Litina, Dimitra; Pontiki, Eleni; Zorc, Branka
Croatica Chemica Acta Vol. 83, No. 2, 2010
A series of novel amino acid ureidoamides 4a-o were prepared from N-(1-benzotriazolecarbonyl)- amino acid chloride 3, derived from L-alanine, L-valine, L-leucine, D-phenylglycine and L-phenylalanine, and the corresponding aminoalcohols (2-amino-1-ethanol, 3-amino-1-propanol and 5-amino-1-pentanol). The compounds were fully characterized by standard spectroscopic methods (IR, 1H and 13C NMR) and their structure was confirmed by elemental analysis. Antioxidant screenings (interaction with 1,1-diphenyl-2-picrylhydrazyl, soybean lipoxygenase inh...
Hrčak ID: 56018


eng Reactions with 1-Benzotriazolecarboxylic Acid Chloride. VIII. Synthesis of <i>N</i>-Hydroxyisocyanate Derivatives
Butula, Ivan; Jadrijević-Mladar Takač, Milena
Croatica Chemica Acta Vol. 73, No. 2, 2000
1,3,5-Trihydroxy-1,3,5-triazine-2,4,6(1<i>H</i>,3<i>H</i>,5<i>H</i>)-trione (<b>5</b>), the trimer of hypothetical acid HO-N=C=O, was synthesized by hydrogenolysis of 1,3,5-tribenzyloxy-1,3,5-triazine-2,4,6(1<i>H</i>,3<i>H</i>,5<i>H</i>)-trione (<b>4</b>). Similarly, the 1-(<i>N</i>-hiydroxycarbamoyl)benzotriazole (<b>6</b>), as »solid HONCO donor«, was prepared by hydrogenolysis of its benzyl derivatives <b>2</b>. Compound <b>4</b> was obtained by trimerization of intermediary <i>N</i>-benzyloxyisocyanate (<b>3</b>), which liberates in the the...
Hrčak ID: 132071


eng Synthesis and Reactions of Some Azolecarboxylic Acid Derivatives
Kalčić, Igor; Zovko, Marijana; Jadrijević-Mladar Takač, Milena; Zorc, Branka; Butula, Ivan
Croatica Chemica Acta Vol. 76, No. 3, 2003
Reaction of several azoles with phosgene or triphosgene was studied. Besides benzotriazole (previously described reaction), only indazole, 5-nitroindazole and 5-methylbenzotriazole gave the corresponding 1-azolecarbonyl chlorides <b>1a-d</b>. Azoles of weak acidity (imidazole, 1,2,3-triazole, 1,2,4-triazole, benzimidazole) could not give stable acyl chlorides, while strong acidic azoles like tetrazole and 4,5,6,7-tetrachlorobenzotriazole did not react at all. Chlorides <b>1b-d</b> readily reacted with alcohols, amines, amino acids and their est...
Hrčak ID: 103171


hrv Čudesna molekula benzotriazol
eng The Curious Molecule Benzotriazole
Butula, I.; Zorc, B.
Kemija u industriji Vol. 56, No. 3, 2007
U ovom radu dan je pregled sintetskih organskih reakcija u kojima je upotrijebljen benzotriazol. Za razliku od većine azola, benzotriazol reagira s fosgenom u molnom omjeru 1:1 i tvori klorid 1- benzotriazolkarboksilne kiseline (BtcCl, 1), koji spremno reagira s nukleofilima dajući reaktivne spojeve iz kojih je pripravljen cijeli niz organskih spojeva: karbamati, uree, semikarbazidi, karbazidi, sulfoniluree, sulfonilkarbazidi, esteri nitroalkanskih kiselina. Nadalje, sintetizirani su različiti heterociklički spojevi: derivati benzoksazina, kina...
Hrčak ID: 12660


eng Application of passivators in transformer insulating mineral oils
Lewand, Lance
Transformers Magazine Vol. 2, No. 2, 2015
Electrical insulating mineral oils are mainly manufactured from naphthenic crude sources, with a small number being produced from paraffinic crudes and gas-to-liquids technology. The resulting products are most frequently free of additives, except for certain types of phenol-based oxidation inhibitors, and of a very low percentage by weight, only up to 0.4 %. The main specifications for electrical insulating oils, Doble TOPS, ASTM D3487 and IEC 60296, only allow oxidation inhibitors and any other additives must be agreed upon by the entities in...
Hrčak ID: 182787