In this paper, a review of reactions with benzotriazole as synthetic auxiliary is given. In contrast to most other azoles, benzotriazole reacts with phosgene in molar ratio 1:1 yielding carboxylic acid chloride (BtcCl, 1), which readily reacts with nucleophiles giving reactive compounds. These products can be easily transformed into carbamates, ureas, semicarbazides, carbazides, sulfonylureas, sulfonylcarbazides, nitroalkanic acid esters, etc. In addition, benzotriazole was used in the synthesis of various heterocyclic compounds: benzoxazine, kinazoline, triazinetrione, hydantoin and oxadiazine derivatives. The reaction of chloride 1 with amino acids enabled the use of benzotriazole in peptide chemistry, with triple role of benzotriazolecarbonyl group as N-protecting, N-activating, and both N-protecting/C-activating group. N-(1-benzotriazolecarbonyl)-amino acids 25 are starting compounds in the synthesis of various amino acid, di- and tripeptide derivatives, hydantoic acids and hydroxyureas.Benzotriazole was also applied in the preparation of polymer-drug and thiomer-drug conjugates, polymeric prodrugs with drugs covalently bound to the polymeric carriers. Such macromolecular prodrugs may offer many advantages compared to other drug delivery systems such as increased drug solubility, prolonged drug release, increased stability. It is also possible to accumulate the drug at the site of the pathological process and to minimize its toxicity. In this paper, the binding of drugs from various therapeutic groups (mostly nonsteroidal, anti-inflammatory drugs) to polymersof polyaspartamide type by the benzotriazolide method is described.
U radu se govori o početku djelovanja knjižnice Prehrambeno tehnološkog fakulteta koji je vezan uz osnivanje Prehrambeno tehnološkog odjela pri Poljoprivredno-prehrambeno tehnološkom fakultetu te prostorima u kojem je knjižnica bila smještena.
This article is the second part of a series dealing with organometallic and bioorganometallic chemistry. In the first part of this series a short review on the history and development of these disciplines was given, emphasizing the importance and scope of bioorganometallic chemistry as a new field dealing with conjugates of organometallics and biomolecules (DNA, PNA, amino acids, peptides...). From the variety of biorganometallics, syntheses and properties of simple conjugates of ferrocene with natural amino acids/peptides were elaborated inter alia. This material is the basis for the second part in which ferrocene amino acids are described. The introduction presents nonproteinogenic alicyclic and aromatic amino acids as the models for the title compounds. Naturally occurring amino acids labelled with ferrocene moiety mostly retain properties of the biomolecules included. Contrary to these ω-ferrocenylamino acids, one could imagine specific amino acids with inserted ferrocene core belonging to either homo- or heterodisubstituted type. The central part of this article is devoted to our investigations of the second type - H2N-(CH2)m-Fn-(CH2)n-COOH. The general rational procedure for synthesis of these compounds and of their N- and/or C-protected derivatives via the azide intermediates N3-CO-(CH2)m- Fn-(CH2)n-COOMe has been described. In the solid state derivatives of ferrocene amino acids contain intermolecular hydrogen bonds giving dimeric structures, three-dimensional networks or endless helical chains. The solutions of homologues Ac-NH-(CH2)m-Fn-(CH2)n-COOMe in nonpolar solvents are dominated by open form conformers. Compounds containing 2–3 ferrocene cores connected by amide, imide and oxalamide spacers were prepared by oligomerization of 1'-aminoferrocene-1-carboxylic acid (Fca) or by its condensation with the appropriate reagents. Similar to natural amino acids, ferrocene amino acids are water-soluble substances with high melting points, insoluble in organic solvents.
Rad se bavi razvojem pojma elementa od antičkih vremena (Empedoklo, Aristotel) preko razdoblja alkemije i rane kemije (Paracelsus, Petar Bono, Boyle) te početaka moderne kemije (Lavoisier, Mendeljejev) do suvremenih shvaćanja utemeljenih na atomskoj teoriji. Pokazuje se da pojam elementa ima dva značenja, elementarne (jednostavne) tvari i elementa u užem smislu; dok se prvi pojam razvijao prateći napredak metoda kemijske analize, za razumijevanje drugog pojma, pojma elementa, bilo je nužno steći dublji uvid u narav kemijskih promjena.