Synthesis, structure, electrostatic properties and spectroscopy of 3-methyl-4,5,6,7-tetrafluoro-1H-indazole. An experimental and ab initio computational study †

Hathaway, Bruce A.; Day, Graeme M.; Lewis, Michael Bevan; Glaser, Rainer

doi:10.1039/a805580g

Cited by 17 publications

(23 citation statements)

References 27 publications

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“…In the condensation of the PFBA with the hydrazine, the (E)-and (Z)-hydrazone form. While (E)-isomer undergoes next a condensation with an appropriate azine formation [508][509][510], the (Z)-isomer reacts in different manner, its cyclization reaction gives 4,5,6,7-tetrafluoro-1H-indazole (Scheme 47 [508]). …”

Section: Chemical Reactions Of Pentafluorobenzaldehyde With Nitrogen mentioning

confidence: 99%

Pentafluorobenzaldehyde and its utilizing in organic synthesis

Pažitný

Solčan

Végh

2009

Journal of Fluorine Chemistry

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Section: Chemical Reactions Of Pentafluorobenzaldehyde With Nitrogen mentioning

confidence: 99%

Pentafluorobenzaldehyde and its utilizing in organic synthesis

Pažitný

Solčan

Végh

2009

Journal of Fluorine Chemistry

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“…3-Methyl-1H-indazole (6), 15,16 3-trifluoromethyl-1H-indazole (7), 17,18 and 3-methyl-4,5,6,7-tetrafluoro-1H-indazole (8) 19 are known compounds whereas 3-trifluoromethyl-4,5,6,7-tetrafluoro-1H-indazole (9) is new. In this study, we have prepared 7 via another approach, the aromatization of the corresponding tetrahydroindazole.…”

Section: Synthesismentioning

confidence: 99%

“…The chemical shifts and coupling constants of compounds 6-9 are reported in Table 2 ( 1 H in CDCl 3 solution), [11][12][13] There has been no previous study on 19 F NMR of indazoles. Obviously, the CF 3 signals are easy to identify, having chemical shifts very similar to those of trifluoromethylpyrazoles.…”

Section: Nmr Spectroscopymentioning

confidence: 99%

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The structure of fluorinated indazoles: the effect of the replacement of a H by a F atom on the supramolecular structure of NH-indazoles

et al. 2007

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The structures of three NH-indazoles (3-methyl, 3-trifluoromethyl and 3-trifluoromethyl-4,5,6,7tetrafluoroindazoles) have been determined by X-ray crystallography. These three compounds, together with 3-methyl-4,5,6,7-tetrafluoroindazole, whose X-ray structure could not be determined, have been studied using multinuclear magnetic resonance spectroscopy, including solid-state CPMAS. They all are 1H-tautomers. In the crystal, 3-methyl-1H-indazole forms hydrogen bonded dimers, whereas 3-trifluoromethyl-1H-indazole and 3-trifluoromethyl-4,5,6,7tetrafluoro-1H-indazole crystallize as catemers. These catemers are chiral space group P3 2. They are the first examples of indazoles crystallizing in the form of helices of threefold screw axis. Attempts at rationalizing this behavior on the basis of supramolecular interactions (hydrogen bonds and aromatic interactions) and GIAO calculations are discussed. The present paper focuses on the four related 1H-indazoles 6-9 depicted in Scheme 2. Scheme 1 Indazoles and a 3-trifluoromethylpyrazole of biological relevance.

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“…Another variation involves the cyclization of arylhydrazines possessing a leaving group in the ortho position (F, NO 2 , OH or OR) [243,[257][258][259][260][261]. These methods also require harsh experimental conditions, such as very high temperatures (200-270 C), although there are references to the synthesis of indazoles by the reaction of ortho-fluorobenzophenone or pentafluoroacetophenone with hydrazine in refluxing ethanol or toluene, respectively [243,262]. Treatment of 2 0 ,6 0 -(dialkoxy-or dihydroxy)acetophenone or benzophenone hydrazones 288 with polyphosphoric acid gives 4-(alkoxy-or hydroxy)-3-substituted-1H-indazoles 289 in moderate to good yields (Scheme 8.85) [263,264].…”

Section: Formation Of One N1àc7a Bondmentioning

confidence: 99%