Improvement of the Friedel–Crafts benzoylation by using bismuth trifluoromethanesulfonate in 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid under microwave irradiation

Bismuth trifluoromethanesulfonate (bismuth triflate) catalyzed the Friedel–Crafts benzoylation of activated aromatic compounds when dissolved in 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM]OTf) ionic liquid. Immobilization of bismuth triflate (5 mol %) in [BMIM]OTf allowed the synthesis of aryl ketones in good to excellent yields with short reaction times under microwave irradiation. This catalytic system was easily recovered and reused several times without any significant loss of the activity.     

Photodegradable Hydrogels for Capture,Detection, and Release of Live Cells

Cells may be captured and released using a photodegradable hydrogel (photogel) functionalized with antibodies. Photogel substrates were used to first isolate human CD4 or CD8 T‐cells from a heterogeneous cell suspension and then to release desired cells or groups of cells by UV‐induced photodegradation. Flow cytometry analysis of the retrieved cells revealed approximately 95 % purity of CD4 and CD8 T‐cells, suggesting that this substrate had excellent specificity. To demonstrate the possibility of sorting cells according to their function, photogel substrates that were functionalized with anti‐CD4 and anti‐TNF‐α antibodies were prepared. Single cells captured and stimulated on such substrates were identified by the fluorescence “halo” after immunofluorescent staining and could be retrieved by site‐specific exposure to UV light through a microscope objective. Overall, it was demonstrated that functional photodegradable hydrogels enable the capture, analysis, and sorting of live cells.     

SYNTHESES OF SOME 35S-LABELLED ORGANIC COMPOUNDS AT BORIS KIDRIČ INSTITUTE - VINČA

Abstract

³⁵-labelled organic compounds are widely used in different fields: medicine, chemistry, biochemistry, biology, etc. Some of these compounds are known as chemoprotectors and ³⁵S-labelled forms are used in the investigation of such protective mechanism. Details of the chemical and biochemical syntheses of some ³⁵S-labelled organic compounds are given in the paper: DL-cysteine hydrochloride-³⁵S (1-amino-2-mercaptopropionic acid), vitamin B₁-³⁵S (thiamin hydrochloride), thiourea-³⁵S, carbon disulphide-³⁵S and L-methionine-³⁵S (1-amino-4-methyl- thiobutyric acid). Products of high specific activities are obtained: 5–10 mCi/mM DL-cysteine hydrochloride-³⁵S; 60–120 mCi/mM vitamin B₁-³⁵S; 100–200 mCi/mM thiourea-³⁵S; 20–100 mCi/mM carbon disulphide- ³⁵S and 1–10 Ci/mM L-methionine-³⁵S. All the products are of high chemical and radiochemical purity, which were determined by thin layer chromatography.     

99mTc Generator — The Maintenance of High Elution Efficiency

Several protecting procedures were applied to ensure good operating performances of the universal ^99mTc generators based on fission produced ⁹⁹Mo. These procedures include the modifications of the adsorbent. Instead of 1 g of pure Al₂O₃ the adsorption of ⁹⁹Mo is carried out on the multicomponent adsorbent containing the mixture of either Al₂O₃ + SiO₂ or Al₂O₃ · Cu²⁺ + SiO₂. The protection by drying should ensure that the columns contain minimum of moisture during the growth period of ^99mTc. It was found experimentally that the best results are obtained when the ratio of alumina in the mixture was 15 ± 5 (wt.%) and content of copper 365 μg Cu²⁺/column. The comparison of efficiency and applicability of the used protecting procedures is also given.     

Rhodium(II)‐Catalyzed Isomerization of Cyclopropenylmethyl Esters into (Acyloxymethylene)cyclopropanes

In the presence of a rhodium(II) catalyst, 3,3‐disubstituted cyclopropenylmethyl esters that possess an electron‐rich or neutral aromatic group undergo isomerization into (acyloxymethylene)cyclopropanes. This transformation, which proceeds with inversion of configuration at the stereogenic center, complements the previously disclosed rearrangement reactions of cyclopropenylmethyl esters. The products arising from this new rhodium‐catalyzed rearrangement contain an enol ester group that can be subsequently functionalized to access stereodefined arylcyclopropanes.     

Efficient Friedel–Crafts benzoylation of aniline derivatives with 4-fluorobenzoyl chloride using copper triflate in the synthesis of aminobenzophenones

An efficient pathway for the synthesis of the aminobenzophenone derivatives via Friedel–Crafts benzoylation using copper triflate as catalyst is proposed. New derivatives are synthesized. The copper triflate could be easily recovered and reused without loss of catalytic activity. Both the use of ionic liquids and microwave heating turned out to be fruitful.