Thioxanthene derivatives with neurotropic activity; synthesis of 9-(3-dimethylaminopropylidene)-2-(methylthiomethyl)thioxanthene and of some related compounds

1984 ◽  
Vol 49 (7) ◽  
pp. 1722-1730 ◽  
Author(s):  
Vojtěch Kmoníček ◽  
Václav Bártl ◽  
Miroslav Protiva
Keyword(s):  
Sulfuric Acid ◽  
Title Compound ◽  
Neurotropic Activity ◽  
Tertiary Alcohol ◽  
Dilute Sulfuric Acid ◽  
Acid Catalyzed ◽  
Sodium Methanethiolate ◽  
Related Compounds

A reaction of 2-(bromomethyl)thioxanthone with sodium methanethiolate with sodium methanethiolate gave 2-(methylthiomethyl)thioxanthone (II) which was transformed by treatment with 3-dimethylaminopropylmagnesium chloride to the tertiary alcohol IV. Its dehydration by heating with dilute sulfuric acid afforded the title compound I. An attempt at preparing the analogous 2-(methoxymethyl) derivative proceeded similarly but failed in the stage of the acid-catalyzed dehydration of the tertiary alcohol V. Acids VIII-XII and the nitrile XIII were prepared as potential intermediates. Compound I has properties of a tranquilizer with a weak cataleptic activity.

Antiaminic agents derived from thieno[2,3-c]-2-benzothiepin: 4-(1-Methyl-4-piperidylidene)-4,9-dihydrothieno[2,3-c]-2-benzothiepin and some related compounds

1983 ◽  
Vol 48 (2) ◽  
pp. 623-641 ◽  
Author(s):  
Zdeněk Polívka ◽  
Miroslav Rajšner ◽  
Jan Metyš ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Sulfuric Acid ◽  
Title Compound ◽  
Amino Alcohol ◽  
Hydrogen Sulfate ◽  
Geometric Isomers ◽  
Pure Alcohol ◽  
Acid Catalyzed ◽  
Anticataleptic Activity ◽  
Related Compounds

In the reaction of thieno[2,3c]-2-benzothiepin-4(9H)-one (VI) with 1-methyl-4-piperidylmagnesium chloride 7-(1-methyl-4-piperidyl)thieno[2,3-c]-2-benzothiepin-4(9H)-one (VIII) is formed in addition to the expected amino alcohol VII. The title compound I was obtained by the acid catalyzed dehydration of the pure alcohol VII. Compound I (pipethiadene) has outstanding antihistamine, antiserotonin, antireserpine and anticataleptic activity and was recommended to clinical trials as a potential antimigraine agent. For pharmacokinetic and metabolic studies there were prepared the NC2H3 analogue of pipethiadene IV and further, as potential metabolites, the demethyl analogue III, S-oxide X, demethyl S-oxide XI, N-oxide XIII and N,S-dioxide XIV. The Witting reaction of the ketone VI with 3-dimethylaminopropylidenetriphenylphosphorane resulted in a mixture of geometric isomers of 4-(3-dimethylamino-propylidene)-4,9-dihydrothieno[2,3-c]-2-benzothiepin with the strongly predominating Z-isomer XVI which was isolated from the mixture by crystallization of the hydrogen maleate. The mixture with the predominating Z-isomer XVI was converted by the treatment with 80% sulfuric acid and dilution with water to a mixture with the predominating E-isomer XV (dithiadene) which was isolated by crystallization of the hydrogen sulfate. Some further new thieno[2,3-c]-2-benzothiepin derivatives were synthesized as potential intermediates.

Statistical Optimization of Sugarcane Leaves Hydrolysis into Simple Sugars by Dilute Sulfuric Acid Catalyzed Process

Sugar Tech ◽  
2011 ◽  
Vol 14 (1) ◽  
pp. 53-60 ◽  
Author(s):  
R. O. Moutta ◽  
Anuj K. Chandel ◽  
R. C. L. B. Rodrigues ◽  
M. B. Silva ◽  
G. J. M. Rocha ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Statistical Optimization ◽  
Dilute Sulfuric Acid ◽  
Acid Catalyzed

Levulinic acid production by two-step acid-catalyzed treatment of Quercus mongolica using dilute sulfuric acid

2017 ◽  
Vol 225 ◽  
pp. 183-190 ◽  
Author(s):  
Hanseob Jeong ◽  
Soo-Kyeong Jang ◽  
Chang-Young Hong ◽  
Seon-Hong Kim ◽  
Su-Yeon Lee ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Production ◽  
Levulinic Acid ◽  
Quercus Mongolica ◽  
Dilute Sulfuric Acid ◽  
Acid Catalyzed

scholarly journals Rearrangements in the acid-catalyzed formation of lactones from 2-hydroxynorbornane-2-acetic acid derivatives and related compounds

1992 ◽  
Vol 70 (9) ◽  
pp. 2491-2501 ◽  
Author(s):  
Peter Yates ◽  
Magdy Kaldas
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Ethyl Esters ◽  
Alkyl Groups ◽  
Acid Lactone ◽  
Concentrated Sulfuric Acid ◽  
Acid Catalyzed ◽  
Preliminary Study ◽  
Related Compounds ◽  
Acetic Acids

A mixture of the epimeric ethyl 2-hydroxynorbornane-2-acetates (1) on treatment with concentrated sulfuric acid is converted in turn to the lactones of exo-2-hydroxynorbornane-1-acetic acid (4), endo-6-hydroxynorbornane-endo-2-acetic acid (5), and exo-3-hydroxynorbornane-exo-2-acetic acid (6). With trifluoroacetic acid or 50% sulfuric acid, 1 gives 4, but this does not react further. In concentrated sulfuric acid the parent acids of 1 (7) and (E)- and (Z)-(norborn-2-ylidene)acetic acids (8 and 9) and their ethyl esters (10 and 11) give 6 as the infinity product. A mixture of 5-norbornene-endo- and exo-2-acetic acid (30 and 31) on treatment with 50% sulfuric acid gives 4, 5, 6, and exo-2-hydroxynorbornane-syn-7-acetic acid lactone (33). Routes are proposed for the formation of the lactones that involve protonation and carbocation formation followed by rearrangement via Wagner–Meerwein, endo-6,2-hydride, and exo-3,2-hydride shifts in decreasing order of preference. It is postulated that the usual inhibition of the rearrangement of tertiary to secondary norbornyl carbocations is not operative when the third substituent is a carboxymethyl group or its derivatives because of the electron-withdrawing properties of such groups relative to simple alkyl groups. A preliminary study has shown that exo-5-acetyloxy-endo-2-hydroxynorbornane-exo-2-acetic acid (35) with 50% sulfuric acid gives four products that are considered to be the γ-lactones of endo-5-acetyloxy- and endo-5-hydroxynorbornane-1-acetic acid (38 and 39) and exo-2-acetyloxy-1-hydroxy-and 1,2-dihydroxynorbornane-syn-7-acetic acid (40 and 41). Protonation of either the hydroxyl or acetyloxyl group is postulated, giving two carbocations that undergo rearrangements as in the case of 1, together with 3,2-hydroxyl shifts. The structures of the lactones are assigned on the basis of spectroscopy, reactivity, and analogy. The reactions of the lactones, which lead to a variety of hydroxy- and oxonorbornaneacetic acids, illustrate their synthetic potential.

Sign in / Sign up

Export Citation Format

Share Document