On Cyclic Intermediates in Substitution Reactions. II. Steric Effects in the Alkaline Hydrolysis of the Epimeric 3-Chloro-6//7-cholestane-dicarboxylic Acids1

1951 ◽  
Vol 73 (5) ◽  
pp. 2392-2394
Author(s):  
Donald W. Wujciak ◽  
Robert L. Feller ◽  
John F. Lane
Keyword(s):  
Alkaline Hydrolysis ◽  
Steric Effects ◽  
Substitution Reactions ◽  
Hydrolysis Of

Neuroleptic 2-chloro-11-(2-piperazineethoxy)-10,11-dihydrodibenzo[b,f]thiepins: Synthesis and pharmacology

1984 ◽  
Vol 49 (8) ◽  
pp. 1810-1815 ◽  
Author(s):  
Václav Bártl ◽  
Jiří Jílek ◽  
Jiřina Metyšová ◽  
Martin Valchář ◽  
Antonín Dlabač ◽  
...  
Keyword(s):  
Alkaline Hydrolysis ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Dopamine Metabolism ◽  
Substitution Reactions ◽  
Activity Profile ◽  
Hydrolysis Of ◽  
Brain Striatum ◽  
Hydroxyethyl Piperazine ◽  
Central Depressant

A reaction of 8-chloro-10,11-dihydrodibenzo[b,f]thiepin-10-ol with 2-bromoethanol and boron trifluoride etherate produced the 2-bromoethyl ether II which was subjected to substitution reactions with 1-methylpiperazine, 1-(2-hydroxyethyl)piperazine, 1-(3-hydroxypropyl)piperazine and 1-ethoxycarbonylpiperazine to give the title piperazinoethoxy compounds IV-VII. Alkaline hydrolysis of the carbamate VII afforded the monosubstituted piperazine VIII. Compounds IV-VI are neuroleptics with an interesting activity profile: they are little toxic, have strong central depressant and antimorphine activity, mild cataleptic effects, they intensively increase the dopamine metabolism in the rat brain striatum and are almost free of the peripheral adrenolytic efficacy.

Thiohydantoins. XI Kinetic Studies of the Alkaline Hydrolysis of 1-Acyl-2-thiohydantoins

1972 ◽  
Vol 50 (23) ◽  
pp. 3780-3788 ◽  
Author(s):  
Wayne I. Congdon ◽  
John T. Edward
Keyword(s):  
Carboxylic Acid ◽  
Alkaline Solution ◽  
Alkaline Hydrolysis ◽  
Ground State ◽  
Kinetic Studies ◽  
Steric Effects ◽  
Hydroxide Ion ◽  
Entropy Of Activation ◽  
Hydrolysis Of ◽  
Conjugate Base

1-Acyl-2-thiohydantoins ionize in alkaline solution (pK ∼ 7). In solutions more alkaline than pH > 11 they are rapidly hydrolyzed to 2-thiohydantoin and a carboxylic acid, by attack of a hydroxide ion on the conjugate base of the 1-acyl-2-thiohydantoin. Possible mechanisms to accord with the entropy of activation, which is less negative than usual for base-catalyzed amide hydrolyses, are discussed. 1-Benzoyl-2-thiohydantoin hydrolyzes more rapidly than 1-acetyl-2-thiohydantoin, possibly because the ground state of the former molecule is destabilized by steric effects.

Potential antipsychotic agents: 2-Chloro- and 2-methyl-11-(2-piperazinoethoxy)-6,11-dihydrodibenzo[b,e]thiepins and some related compounds; Synthesis and pharmacology

1984 ◽  
Vol 49 (11) ◽  
pp. 2520-2530 ◽  
Author(s):  
Václav Bártl ◽  
Karel Šindelář ◽  
Vladimír Valenta ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Alkaline Hydrolysis ◽  
Antipsychotic Agents ◽  
Similar Reaction ◽  
Substitution Reactions ◽  
Single Product ◽  
Hydrolysis Of ◽  
Related Compounds ◽  
Hydroxyethyl Piperazine ◽  
Neuroleptic Activity

Reactions of 2-chloro- and 2-methyl-6,11-dihydrodibenzo[b,e]thiepin-11-ol with 2-bromoethanol in the presence of sulfuric acid in boiling benzene afforded the 2-bromoethyl ethers VIa and VIb which were transformed by substitution reactions with 1-methylpiperazine, 1-(2-hydroxyethyl)-piperazine and 1-(ethoxycarbonyl)piperazine to the title compounds. Alkaline hydrolysis of the carbamate IVa gave the secondary amine IIIa. Treatment of the bromo ether VIa with 4-(4-chloro-3-trifluoromethylphenyl)piperidin-4-ol resulted in the piperidine derivative VIIa. Substitution reaction of 11-chloro-6,11-dihydrodibenzo[b,e]thiepin with 1-(2-methoxyethyl)piperazine and 1-(2-ethoxyethyl)piperazine led to the amino ethers VIII and IX. Reaction of 11-chloro-11-phenyl-6,11-dihydrodibenzo[b,e]thiepin with 2-dimethylaminoethanethiol in dimethylformamide at 90°C gave a mixture of two isomeric bases which was separated to the expected sulfide X and the base XII, resulting evidently after the rearrangement of the primary carbocation. A similar reaction of 3-dimethylaminopropanethiol afforded a single product of structure XI. Out of the compounds prepared, the ether VIII was found most interesting: it is little toxic and has significant antireserpine activity in two tests (is considered a potential antidepressant). The ethers Iab, Iab, IIIa and VIIa did not reveal the expected neuroleptic activity.

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