Pyridine-2 -thione

Pyridin-4-ones, from 5-hydroxy-THISs. 10 Pyridin-4-thiones, from 5-hydroxy-THISs. 

FIGURE 3. Thiocarbonyl ligands involved in Tables 20-25 (a) pyridine-2-thione, (b) pyridine-4-thione, (c) pyrimidine-2-thione, (d) l,3-imidazoline-2-thione, (e) benz-l,3-imidazoline-2-thione, (f) l,3-imidazolidine-2-thione, (g) l,3-thiazoline-2-thione, (h) benz-1,3-thiazoline-2-thione, (i) 1,3-thiazolidine-2-thione, (j) 1,2,4-triazoline-3(5)-thione, (k) 1,2,3,4-tetrazoline-5-thione... 

Calculate number of sulfhydryl groups (molar extinction coefficient of 19800 for the modified, pyridine-4-thione, thiol groups). 

Ion cyclotron resonance studies confirm earlier conclusions based on photoelectron spectroscopic data that pyridine-4-thione exists mainly as the thiol tautomer in the gas phase. The potential of this technique for measuring tautomeric equilibrium constants in the gas phase is discussed. Alkylation of ambident anions of the type [N—C—S] , e.g. pyridine-2-thione, in the presence of a phase-transfer catalyst (Bu4N Br") leads exclusively to the, S-alkylated products. Yields are generally superior to those obtained by more conventional methods, and easier experimental work-up procedures are claimed for a variety of systems, including pyridine-2-thione, pyrimidine-2-thione, and benz-oxazoline-2-thione. Energies and Alkylations of Tautomeric Heterocyclic... 

This probably arises from the intermediate (58) by ring opening of the vic-triazole ring, as is suggested by the observation that l,5-dihydro-4H-t ic-triazolo[4,5-c]pyridine-4-thione (57) in refluxing propanol gives rise to an equilibrium mixture of (56) and (57). The reconversion (70%) of (56) into... 

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