Synthesis of Substituted Aminopyrimidines as Novel Promising Tyrosine Kinase Inhibitors

Russian Journal of Organic Chemistry - A procedure has been proposed for the synthesis of a series of substituted N-(1,3-thiazol-2-yl)-pyrimidin-2-amines and N-(pyrimidin-2-yl)thioureas by...     

Three-Component Condencations of 3-Amino-1,2,4-triazoles,Methyl 3-(2-Cycloamino-4-methylpyrimidin-5-yl)-3-oxopropionoates,and a Series of C1 Synthons as a Convenient Approach to Pyrimidin-5-yl-1,2,4-triazolo[1,5-a]pyrimidines

Russian Journal of Organic Chemistry - A convenient synthetic approach to polysubstituted dihydrogenated or heteroaromatic 1,2,4-triazolo[1,5-a]pyrimidines derivatives containing at position 5 a...     

Synthesis of polyazaheterocycles containing linearly bound 1,2,4-thiadiazole using enaminones

A reaction of N-substituted 5-amino-3-(2-oxopropyl)-1,2,4-thiadiazoles with dimethylformamide dimethyl acetal gave 3-(5-amino-1,2,4-thiadiazol-3-yl)-4-(dimethylamino)but-3en-2-ones, whose cyclization with hydrazine, guanidine, 1H-pyrazol-5-amines and 6-aminopyrimidin-4(3H)-ones led to 3-methyl-1H-pyrazole, 4-methylpyrimidin-2-amine, 5-methyl3-arylpyrazolo[1,5-a]pyrimidines, and 5-methyl-2-R-pyrido[2,3-d]pyrimidin-4(3H)-ones containing a 5-amino-1,2,4-thiadiazole fragment linearly bound at position 3.     

Crystal chemistry of clay minerals in bottom sediments of the Sea of Okhotsk as a paleoclimatic indicator

X-ray diffraction and infrared spectroscopy were used to study the mineral composition of bottom sediments of the Sea of Okhotsk with ages ranging from Holocene (10 My ago) to Pleistocene (10 to ～74 My ago). The concentrations of nonlayered minerals (quartz, plagioclase, carbonates, and biogenic silica) were determined from IR spectra, which made it possible to estimate the actual abundance of the clay component in test samples. Calibration curves used in the calculation were plots of the optical density in the maximum of the analytical absorption band of the analyzed component versus its concentration in the sample. These curves were constructed for standard mixtures of known compositions. The crystal-chemical parameters and quantitative ratios of clay minerals were elucidated by the computer simulation of X-ray diffraction profiles; clear correlations were found between these parameters and paleoclimatic changes. Our results show that the clay minerals from the bottom sediments of the Sea of Okhotsk can serve to search for paleoclimatic events in the North-Eastern Asia.