ChemInform Abstract: SYNTHESIS OF 2-AMINO-5,6-DIHYDRO-4H-1,3-THIAZINES AND RELATED COMPOUNDS BY ACID CATALYZED CYCLIZATION OF ALLYLIC ISOTHIURONIUM SALTS

1978 ◽  
Vol 9 (18) ◽  
Author(s):  
N. COHEN ◽  
B. L. BANNER
Keyword(s):  
Acid Catalyzed ◽  
Related Compounds

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.

scholarly journals Acid-catalyzed rearrangement of hinesol and related compounds to eudesmane derivatives.

1983 ◽  
Vol 31 (6) ◽  
pp. 1991-1997 ◽  
Author(s):  
HIDEJI ITOKAWA ◽  
HIROSHI NAKANISHI ◽  
SUSUMU MIHASHI
Keyword(s):  
Acid Catalyzed ◽  
Related Compounds

Synthesis of 5H-dibenzo[a,d]cycloheptene-5-carboxylic acid and related compounds. 1,5-Hydride transfer to inductively destabilized carbonium ions

1968 ◽  
Vol 46 (23) ◽  
pp. 3665-3670 ◽  
Author(s):  
D. E. Horning ◽  
J. M. Muchowski
Keyword(s):  
Carboxylic Acid ◽  
Carbonyl Group ◽  
Isotope Effect ◽  
Hydride Transfer ◽  
Large Magnitude ◽  
Carbonium Ion ◽  
Carbonium Ions ◽  
Acid Catalyzed ◽  
Derivatives Of ◽  
Related Compounds

The synthesis of 10,11-dihydro-5H-dibenzo[a,d]cycloheptene-5-carboxylic acid (2) and several derivatives of 5H-dibenzo[a,d]cycloheptene-5-carboxylic acid (1; a–c) from 5-hydroxy-10,11-dihydro-5H-dibenzo[a,d]cycloheptene-5-carboxylic acid and derivatives thereof (3; a–c) is described.The p-toluenesulfonic acid-catalyzed elimination of water (at 110.6° in toluene) from the deuterated hydroxy ester (3b; C-10, 11 d2) resulted in the incorporation of deuterium at C-5 of the olefinic ester 1b with a KH/KD of 2.76. The large magnitude of this isotope effect indicated that the reaction proceeded via a rate-determining transannular 1,5-hydride transfer from one of the benzylic positions of 3b to the carbonium ion generated alpha to the methoxy-carbonyl group.

scholarly journals Carcinogenic effects of N-nitroso compounds in the environment

2020 ◽  
pp. 25-41
Author(s):  
Divya Jain ◽  
Priya Chaudhary ◽  
Nidhi Varshney ◽  
Pracheta Janmeda
Keyword(s):  
Reactive Nitrogen Species ◽  
Population Studies ◽  
Nitroso Compounds ◽  
Nitrogen Compounds ◽  
Nitrogen Species ◽  
Gi Tract ◽  
Main Site ◽  
Carcinogenic Effects ◽  
Acid Catalyzed ◽  
Related Compounds

N-nitroso compounds (NOC) are produced by the acid catalyzed reaction of nitrite with certain nitrogen compounds. The gastrointestinal tract (GI) is the main site for the formation of reactive nitrogen species (RNS). Bacteria present on the GI tract surface reduced the dietary nitrate or nitrite into Nitric oxide NO and other related compounds. The clinical sign of NOC carcinogenicity varies according to species, dose, and route of administration. Humans are exposed to preformed N-nitroso compounds and endogenous NOC via the environmental food chain. Several NOC are potential human carcinogens, including DENA and NDMA, but evidence from population studies is inconsistent.

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