• Journal of the Korean Chemical Society
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• v.20 no.3
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• pp.221-228
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• 1976

The kinetics of hydrolysis of hydrazonyl bromides $(p-H,\;p-CH_3,\;p-OCH_3,\;p-Br,\;p-Cl\;&\;p-NO_2)$ have been investigated by UV spectrometry in $60{\%}$ dioxane-water at $25^{\circ}C$ and a rate equation which can be applied over wide pH range was obtained. Below pH2, the rate of hydrolysis of a series of hydrazonyl bromide is accelerated by electrondonating group (${\rho}$ = -0. 94) whereas at the pH values greater than 4, the ${\rho}$-value is 0.54. The rate equation, solvent-, substituent-and bromide ion-effect on the rate of hydrolysis are rationalized in terms of $S_N1$ and $S_N2$ mechanism: below pH 2, the hydrolysis proceed through $S_N2$, however, above pH 4, the hydrolysis is started by the attack of hydroxide ion and in the range pH 2{\sim}$4, these two reactions occur competitively.

• Archives of Pharmacal Research
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• v.14 no.3
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• pp.266-270
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• 1991

Synthesis of C-(2-furyl)-N-(4-nitrophenyl)methanohydrazonyl bromide 2 is described. Treatment of 2 with uncleophiles affords the corresponding substitution products 3-7. Also, compound 2 reacts with selenocyanate anion and thiocyanate anion and give the corresponding selenadiazoline and thiadiazoline 8 and 9, respectively. Moreover, reaction of 2 with enolates of various active methylene compounds afforded the pyrazole derivatives 17-20.