Fvp of bis- and tris-(pyrazol-1-yl)methane. A radical reaction

An experimental (flash vacuum pyrolysis) and theoretical study of the tautomerism of pyrazolinones at high temperatures

“…For several years we have been interested in the flash vacuum pyrolysis (FVP) of pyrazoles and indazoles (benzopyrazoles). [1][2][3][4][5][6][7] Pyrazolinones have four tautomers, two of which, 1c and 1d, are 5-and 3-hydroxypyrazole derivatives: 8 As a natural extension of our work, we decided to subject some pyrazolinones to FVP and to calculate theoretically the effect of the temperature on the equilibria between the above represented tautomers of 1. In addition, we determined experimentally the variation of K T with the temperature by 1 H NMR in solution for a model compound.…”

Flash Vacuum Pyrolysis of Pyrazoles as an Alternative Way to Study Vinylcarbenes

“…Reactions of type a are typical of N -substituted compounds, and the kind of reaction depends on the N1 substituent. For example, pyrazole elimination occurs if this is an alkyl group with β H, isomerizations occur if it is aromatic,4a benzoyl,4b or adamantyl,4c and radical formation occurs if it is a benzoyl group 4b or if the compound is a polyazolylmethane …”

Reactivity of bis(pyrazol-1-yl)methanes functionalized by 2-hydroxyphenyl and 2-methoxyphenyl on the methine carbon atom with W(CO)5THF

“…The pyrolysis of bis(pyrazol-1-yl)methanes has been reported, and a radical mechanism was suggested to explain the formation of the corresponding pyrazole derivatives [37]. Based on these results and other known facts, plausible reaction pathways of L 1 -L 4 with W(CO) 5 In conclusion, reactions of bis(pyrazol-1-yl)methanes functionalized by 2-hydroxyphenyl and 2-methoxyphenyl on the bridgehead carbon atom with W(CO) 5 THF have been carried out.…”