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2-Hydroxy-2-(polyhaloalkyl)chroman-4-ones react with diethoxymethyl acetate at 140-150°C for 15 minutes to give 3-(polyhaloacyl)chromones in good yields. The reactions of these compounds with amines proceeds at C-2 with pyrone ring-opening and formation of 2-(alkyl/arylaminomethylene)-2-hydroxy-2-(polyfluoroalkyl)chroman-4-ones.

Condensation of 4 acetyl 5 hydroxy 3 methyl 1 phenylpyrazole with R F CO 2 Et (R F = CF 2 H, CF 3 ) in the presence of LiH affords 4 di(tri)fluoroacetoacetyl 5 hydroxy 3 methyl 1 phenylpyrazoles from which 6 di(tri)fluoromethyl and 5 di(tri)fluoroacetyl 3 methyl 1 phenylpyrano[2,3 c]pyrazol 4(1H ) ones were synthesized. The reactions of pyrano pyrazoles with hydrazine hydrate, ethyl mercaptoacetate, or aromatic amines proceed at the C(6) atom with pyrone ring opening and formation of aminoenones, pyrazoles, or thiophenes with the 5 hydroxy 3 methyl 1 phenyl 4 pyrazolyl fragment.Key words: 6 di(tri)fluoromethyl and 5 di(tri)fluoroacetyl 3 methyl 1 phenylpyra no[2,3 c]pyrazol 4(1H ) ones, diethoxymethyl acetate, substituted pyrazoles, thiophenes and thieno[3´,2´:4,5]pyrano[2,3 c]pyrazol 5(3H ) one.

Pyrazole derivativesPyrazole derivatives R 0180 2-Polyfluoroalkylchromones. Part 11. Synthesis and Structures of 5-Hydroxy- 3-(2-hydroxyaryl)-5-polyfluoroalkyl-∆ 2 -pyrazolines and 3(5)-(2-Hydroxyaryl)-5(3)-polyfluoroalkylpyrazoles. -Reactions of 2-polyfluoroalkylchromones and related 2-hydroxychromanones with hydrazine, phenylhydrazine, and methylhydrazine affording various previously undescribed pyrazolines and pyrazoles with 2-hydroxyaryl and polyfluoroalkyl substituents in positions 3 or 5 are described. -(SOSNOVSKIKH*, V. Y.; BARABANOV, M. A.; SIZOV, A. Y.; Russ.

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