E. Bartoszak-Adamska

5-Ethynyl-1-β-D-ribofuranosyl-1H-[1,2,3]triazole-4-carboxylic acid amide (ETCAR) and its analogues: synthesis and cytotoxic properties.

Efficient Pd(0)-catalysed synthesis of 5-alkynyl-1-β-D-ribofuranosyl-1H-[1,2,3]triazole-4-carboxylic acid amide depends on the presence of different protecting groups of the ribose moiety. Peracetylated 5-iodo substrate (15) couples with terminal alkynes or trimethyl-[(tributylstannyl)ethynyl]silane in 50-71% and 72% yield (ETCAR), respectively, although its hydrodehalogenation to 19 is noticeable. On the other hand, hydrodehalogenation of acetonide (16) predominates over coupling with terminal alkyne and slightly decreases a yield of cross-coupling reaction with trimethyl[(tributylstannyl)ethynyl]silane. Alternative conditions of reaction with terminal alkynes, to exclude so far identified hydride sources to produce hydridopalladium species, have been established for acetonide 16 and allowed to achieve 72% of coupling. Fluoromethyl derivative (42) was prepared from its 5-hydroxymethyl precursor by fluorination with DAST. Additionally, X-ray structural analysis of 42 was performed. All 1,2,3-triazolonucleosides and two synthesized cycloSal-pronucleotides were evaluated for cytotoxic activity against K562, HeLa and HUVEC cells.

Crystal structure of the new intermetallic compound Zr2−xLix+ySi1−y (x=0.17, y=0.12) and its relation with the disilicide ZrSi2

Abstract The crystal structure of the new compound Zr 2− x Li x + y Si 1− y ( x =0.17, y =0.12) was investigated by X-ray single crystal diffraction. The compound is an antitype to the CaSb 2 structure type, P 2 1 / m space group ( a =3.701(1) A, b =3.669(1) A, c =7.581(2) A, β =103.70(3)°, R =0.0408 for 282 unique reflections).

Crystallographic investigation of the ternary compounds in the Zr–Li–Si system

Abstract By means of X-ray structural analysis the isothermal section of the Zr–Li–Si phase diagram at 470 K has been built. Four new ZrLi2Si, ZrLiSi, Zr4Li1.38Si4 and Zr2−xLix+ySi1−y (x=0.17, y=0.12) ternary compounds have been found in this system. The ZrLi2Si compound crystallizes in the ZnLi2Si structure type (space group P 3 m1 ), ZrLiSi compound crystallizes in the CdJ2 structure type (space group P 3 m1 ). Crystal structure of the Zr4Li1.38Si4 (new structure type, space group Cmcm) and Zr2−xLix+ySi1−y (x=0.17, y=0.12) compounds were investigated by the X-ray single crystal methods. The Zr2−xLix+ySi1−y (x=0.17, y=0.12) new ternary compound is a antitype to the CaSb2 structure type (space group P21/m).

Synthesis, structure and biological evaluation of novel bicyclic nitroimidazole derivatives.

A new series of 3‐hydroxy‐8‐nitroimidazo[5,1‐b]‐1,4,5,6‐tetrahydropyrimidine systems, being potential tuberculostatic agents, were synthesized. These products are close structural analogs of the basic structure of the known antitubercular bicyclic nitroimidazooxazine PA‐824. The structures of the products obtained were confirmed by X‐ray methods on the example of 3‐hydroxy‐8‐nitro‐1‐phenylaminoimidazo[5,1‐b]‐1,4,5,6‐tetrahydropyrimidine. Evaluation of these products for their anti‐tuberculosis effects revealed interesting structure–activity relationships.