Mannich reaction in the synthesis of N,S-containing heterocycles. 14*. Unexpected formation of thiazolo[3,2-a]pyridines in the aminoalkylation of N-methylmorpholinium 4-aryl-3-cyano-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolates by isobutyraldehyde and primary amines

Treatment of N-methylmorpholinium 4-aryl-3-cyano-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolates with an excess of isobutyraldehyde and primary aromatic amines in refluxing ethanol gives the corresponding 7-aryl-3-arylamino-2,2-dimethyl-5-oxo-2,3,6,7-tetrahydro-5 H-thiazolo[3,2-a]pyridine-8-carbonitriles in 18-38 % yields.     

Real Forms of Elliptic Integrable Systems

Theoretical and Mathematical Physics - We describe the real forms of classical elliptic integrable systems such as the elliptic Calogero-Moser system and the elliptic Euler-Arnold top in the...     

Oxidation of 2-Cyanothioacrylamides with Sodium Nitrite in Acidic Medium

Russian Journal of General Chemistry - (E)-3-Aryl-2-cyanoprop-2-entioamides, prepared by Knoevenagel condensation between aromatic aldehydes and cyanothioacetamide, react with sodium nitrite in...     

Reaction of Ethoxymethylenemalonate with Cyanothioacetamide in the Presence of Triethylamine: Formation of 1,5-Diamino-2,4-dicyano-5-thioxopenta-1,3-diene-1-thiolate and Unexpected Aminomethylation Result

The reaction of cyanothioacetamide with ethoxymethylenemalonate and triethylamine in ethanol upon heating is non-selective and leads to the formation of a mixture of triethylammonium 1,5-diamino-2,4-dicyano-5-thioxopenta-1,3-diene-1-thiolate and triethylammonium 6-oxo-3-cyano-5-ethoxycarbonyl-1H-pyridin-2-thiolate with a predominance of the latter. When treating with primary amines and 37% formalin in boiling aqueous alcohol, the reaction product gives only 4-(1,3,5-thiadiazinan-2-ylidene)-2-(3,4-dihydro-2H-1,3,5-thiadiazin-6-yl)pent-2-enedinitrile instead of the expected pyrido[2,1-b][1,3,5]thiadiazine derivatives. Triethylammonium 6-oxo-3-cyano-5-ethoxycarbonyl-1H-pyridin-2-thiolate does not react under these conditions.     

Effect of the magnetic flux trapping upon the temperature dependence of the flow stress change at the superconducting transition

The effect of the superconducting transition on the flow stress in single and polycrystals of Pb-In and Pb-Sn alloys has been studied in the temperature range 1.8 K to T_e. Unlike earlier efforts, these experiments involved investigation of the magnetic flux trapping. Two types of temperature dependences of the magnetic flux trapping, B₀(T), were revealed. In Pb-1.9 at.% In and Pb-6 at.% Sn alloys (subjected to various thermal treatment), B₀ monotonically rises with lowering temperature. In Pb-1.8, 3 at.% Sn single crystals the flux trapping arises at high strains (> 50%) and low temperatures (<2.5 K). In this case B₀ magnitude depends on the strain rate. The difference in the B₀(T) behaviour is associated with dissimilar flux pinnig by pinning centres. The date on B₀(T) obtained give an insight into the two types of the Δσ(T) dependences; taking into account of the flux trapping allowed the Δσ values to be corrected, so that as a result, a single Δσ_SN(T) curve was obtained for all the alloys and structures studied.