Fluorinated Nitrogen Heterocycles via Cyclization. I. Trifluoromethyl-2-pyridones from Fluorinated 1,3-Dicarbonyls and Cyanoacetamide

Regioselective synthesis and properties of 3-cyano-6-methyl-4-trifluoromethylpyridine-2(1H)-thione. Molecular and crystal structure of 3-cyano-2-ethylthio-6-methyl-4-trifluoromethylpyridine

“…The reactions of 3-cyanopyridine-2( 1H)-thiones with halogenocarbonyl compounds are widely used in the synthesis of fused pyridines.LZ, 4 We found that N-arylehloroaeetamides 8--10 readily reacted with pyridinethione 1 to form pyridylthioacetoamides 11--13. When compounds 11--13 were treated with an aqueous KOH solution in DMF, 3-aminothieno[2,3-b]pyridinecarboxamides 14--16 were obtained in good yields.…”

“…4 Only the structure of 3-cyano-6-phenyl-4-trifluoromethylpyridine-2(114)-thione was determined by oxidative desulfurization of this compound to the corresponding pyridone, s…”

Fluorinated nitrogen heterocycles via cyclization. IV. s‐Triazolo[4,3‐a] pyridines and tetrazolo[1,5‐a] pyridines from 4‐trifluoromethyl‐2‐hydrazinopyridines

“…trifluoromethyl-2-hydrazinopyridines (I) were prepared by the action of hydrazine hydrate on the appropriate 2-chloropyridine compound (l), themselves obtained from the respective 2-pyridone(15).Weak absorptions of the -C=N-grouping of the ring system are shown by both series of compounds in the 1640-1660 cm-' region(Table 11) ( 3 ) . Bands characteristic of pyridine ring stretching (16) appear in the region 1410-1600 c m -' .…”

Fluorinated nitrogen heterocycles via cyclization. III. 3‐trifluoromethyl‐1‐(4‐trifluoromethyl‐2‐pyridyl)‐pyrazoles from fluorinated 1,3‐diketones and 4‐trifluoromethyl‐2‐hydrazinopyridines

“…The preparation of trifluoromethylpyrazoles from hydrazine and fluorinated 1,S-diketones has been sparsely reported (l,2). In continuation of work on the preparation of new fluorinated nitrogen heterocycles (3,4), this laboratory has extended this reaction to the fluorinated hydrazinopyridines. I t was found that when 4-trifluoromethyl-2hydrazinopyridines (IV, Table 111) were reacted with fluorinated 1 ,3-diketones having the general structure CP3COCH2COKI, where K 1 = CH3, C6H5, 2-C4H3S (2thienyl) or 2-C4 H 0(2-furyl), cyclizations occurred giving, in most cases, the desired pyrazole compounds (Va-j, Table IV).…”