Nucleophilic substitutions in mixed solvents. Part II. Acid chlorides and alcohols in carbon tetrachloride

1966 ◽  
pp. 766 ◽  
Author(s):  
R. F. Hudson ◽  
G. W. Loveday
Keyword(s):  
Carbon Tetrachloride ◽  
Mixed Solvents ◽  
Acid Chlorides ◽  
Nucleophilic Substitutions

Substituent and solvent effects on the reaction between 2,6-Di-t-butyl-α-(3,5-di-t-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)-p-tolyloxyl (galvinoxyl) and phenols

1978 ◽  
Vol 31 (6) ◽  
pp. 1201 ◽  
Author(s):  
N Nishimura ◽  
K Okahashi ◽  
T Yukutomi ◽  
A Fujiwara ◽  
S Kubo
Keyword(s):  
Carbon Tetrachloride ◽  
Binary Mixtures ◽  
Solvent Effects ◽  
Rate Constants ◽  
Isotope Effects ◽  
Mixed Solvents ◽  
Transition States ◽  
Activation Parameters ◽  
Substituted Phenols ◽  
Kinetic Behaviour

Rate constants and associated activation parameters for the reaction of galvinoxyl with substituted phenols were obtained in carbon tetrachloride and in cyclohexane-dioxan binary mixtures. Substantial isotope effects were observed for O-deuterated phenols. The rate constants are correlated with σ+ values. These findings are discussed by considering the polar contribution of substituents to the stabilization of the transition states. In the mixed solvents, the kinetic behaviour is well expressed by the equations which are based on the theory of Kondo and Tokura.

Pyridazino[3,4,5-de]phthalazines. I. Synthesis of the heterocyclic system and key intermediates

1979 ◽  
Vol 57 (24) ◽  
pp. 3320-3331 ◽  
Author(s):  
John E. Francis ◽  
Karl J. Doebel ◽  
Paula M. Schutte ◽  
Edgar C. Savarese ◽  
Stephen E. Hopkins ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Clinical Trials ◽  
Free Radical ◽  
Carbon Tetrachloride ◽  
Hydrazine Hydrate ◽  
Nitrous Acid ◽  
Heterocyclic System ◽  
Acid Chlorides ◽  
Test Models ◽  
Methyl Cellosolve

1H-Pyridazino[3,4,5-de]phthalazine (4) and 3-hydrazino-1(or 9) H-pyridazino[3,4,5-de]-phthalazine (6) represent intramolecular hydrazones of the drugs hydralazine and dihydralazine, respectively. These novel heterocycles were synthesized by several different routes starting from 2,6-dimethylbenzoic acid, 3-methylphthalic anhydride, or hemimellitic acid. Tetrabromination of 2,6-dimethylbenzoic acid with bromine and carbon tetrachloride under free radical conditions followed by treatment with dilute aqueous hydrazine hydrate produced pure 4 in yields up to 58%. Treatment of 3-methylphthalic anhydride with 2 mol of N-bromosuccinimide under radical conditions followed by reaction of the dibromo compound with hydrazine hydrate in methyl Cellosolve produced 3-oxo-3H-2,9(or 1,2)-dihydropyridazino[3,4,5-de]phthalazine in 60% yield. This intermediate was converted to the 3-thiono compound or 3-chloro-1(or 9)H-pyridazino[3,4,5-de]phthalazine from which the hydrazine 6 was generated by hydrazine hydrate treatment. This hydrazine was further characterized by conversion with acid chlorides to novel tetracyclic condensed triazoles or by nitrous acid to a tetracyclic condensed tetrazole. The unsubstituted heterocycle 4 was uninteresting in pharmacological screens but the hydrazine 6 resembled hydralazine by lowering blood pressure in several animal test models and in limited clinical trials.

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