Cyclization Kinetics of N-(β-Haloalkyl)benzenesulfonamides

1966 ◽  
Vol 31 (2) ◽  
pp. 568-575 ◽  
Author(s):  
Walter J. Gensler ◽  
Barry A. Brooks
Keyword(s):  
Cyclization Kinetics ◽  
Kinetics Of

Kinetics and mechanism of cyclization of N-(2-methoxycarbonylphenyl)-N’-methylsulphonamide to 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide

1991 ◽  
Vol 56 (8) ◽  
pp. 1701-1710 ◽  
Author(s):  
Jaromír Kaválek ◽  
Vladimír Macháček ◽  
Miloš Sedlák ◽  
Vojeslav Štěrba
Keyword(s):  
Potassium Hydroxide ◽  
Acid Catalysis ◽  
Potassium Hydroxide Solution ◽  
Hydroxide Solution ◽  
General Base ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Cyclization Kinetics ◽  
Rate Limiting ◽  
Kinetics Of

The cyclization kinetics of N-(2-methylcarbonylphenyl)-N’-methylsulfonamide (IIb) into 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide (Ib) has been studied in ethanolamine, morpholine, and butylamine buffers and in potassium hydroxide solution. The cyclization is subject to general base and general acid catalysis. The value of the Bronsted coefficient β is about 0.1, which indicates that splitting off of the proton from negatively charged tetrahedral intermediate represents the rate-limiting and thermodynamically favourable step. In the solutions of potassium hydroxide the cyclization of dianion of the starting ester IIb probably becomes the rate-limiting step.

Cyclization kinetics of poly(acrylonitrile)

Carbon ◽  
1996 ◽  
Vol 34 (5) ◽  
pp. 561-566 ◽  
Author(s):  
L.A. Beltz ◽  
R.R. Gustafson
Keyword(s):  
Cyclization Kinetics ◽  
Kinetics Of ◽  
Poly Acrylonitrile

Cyclization kinetics and mechanism of N-benzoyl-N'-(1,2-dimethyl-3-oxo-1-butenyl)thiourea

1983 ◽  
Vol 48 (2) ◽  
pp. 578-585 ◽  
Author(s):  
Jaromír Kaválek ◽  
Tomáš Potěšil ◽  
Vojeslav Štěrba
Keyword(s):  
Hydrochloric Acid ◽  
Secondary Amines ◽  
Tertiary Amines ◽  
Cyclization Product ◽  
Ph Values ◽  
Hydroxyl Ion ◽  
Primary And Secondary Amines ◽  
Acids And Bases ◽  
Cyclization Kinetics ◽  
Kinetics Of

Cyclization kinetics of N-benzoyl-N'-(1,2-dimethyl-3-oxo-1-butenyl)thiourea have been studied in aqueous and methanolic solutions of acids and bases. In all cases the cyclization product is 4,5,6-trimethyl-2,5-dihydro-2-thioxopyrimidine or its protonated or deprotonated forms. In dilute methanolic and aqueous hydrochloric acid the substrate reacts in its monoprotonated form. The cyclization in basic media is catalyzed by methoxide or hydroxyl ion and also by primary and secondary amines at such pH values where the catalysis by lyate ion is practically insignificant. Tertiary amines and acetate ion do not catalyze the cyclization.

scholarly journals Reactive conformations and non-Markovian cyclization kinetics of a Rouse polymer

2013 ◽  
Vol 138 (9) ◽  
pp. 094908 ◽  
Author(s):  
T. Guérin ◽  
O. Bénichou ◽  
R. Voituriez
Keyword(s):  
Cyclization Kinetics ◽  
Kinetics Of

Kinetics of Cyclization of Methyl S-(2,4,6-Trinitrophenyl)mercaptoacetate to 2-Methoxycarbonyl-5,7-dinitrobenzo[d]thiazol-3-oxide

1997 ◽  
Vol 62 (9) ◽  
pp. 1429-1445 ◽  
Author(s):  
Marek Janík ◽  
Vladimír Macháček ◽  
Oldřich Pytela
Keyword(s):  
Rate Equation ◽  
Reaction Order ◽  
Gradual Decrease ◽  
Reaction Paths ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Cyclization Kinetics ◽  
The Given ◽  
Rate Limiting ◽  
Kinetics Of

The cyclization kinetics of methyl S-(2,4,6-trinitrophenyl)mercaptoacetate to 2-methoxycarbonyl-5,7-dinitrobenzo[d]thiazol-3-oxide have been studied in acetate, methoxyacetate or N-methylmorpholine buffers. In the acetate and methoxyacetate buffers, the cyclization obeys the rate equation v = [SH](k'MeO[CH3O-] + k'B[B-] + k'B,MeO[B-][CH3O-]) and goes by two reaction paths differing in the order of their reaction steps, the splitting off of the proton from C-H group being the rate-limiting step in either path. In the N-methylmorpholine buffers, increasing concentration of the base results in gradual decrease of reaction order in the base and change in the rate-limiting step of cyclization. Methyl S-(2,4-dinitrophenyl)mercaptoacetate undergoes cyclization neither in the given buffers nor in methoxide solution.

Kinetics and Mechanism of Cyclization of N-(2-Methoxycarbonylphenyl)-N-methylsulfonamide to 1-Methyl-(1H)-2,1,3-benzothiadiazine-4(3H)-one-2,2-dioxide

1992 ◽  
Vol 57 (6) ◽  
pp. 1282-1290 ◽  
Author(s):  
Jaromír Kaválek ◽  
Vladimír Macháček ◽  
Miloš Sedlák ◽  
Vojeslav Štěrba
Keyword(s):  
Potassium Hydroxide ◽  
Kinetics And Mechanism ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Conjugate Acid ◽  
Cyclization Kinetics ◽  
Rate Limiting ◽  
Kinetics Of ◽  
Cyclic Intermediate

The cyclization kinetics of N-(2-methoxycarbonylphenyl)-N-methylsulfonamide to 1-methyl-(1H)-2,1,3-benzothiadiazine-4(3H)-one-2,2-dioxide have been studied in glycinamide, morpholine, and butylamine buffers and in solutions of potassium hydroxide. The rate-limiting step consists in splitting off of the proton from the cyclic intermediate formed from the anion of the starting substrate. The value of the Bronsted coefficient β decreases with increasing pKa value of the conjugate acid of buffer. The calculated pKa value of the cyclic intermediate is 9.3.

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