Potential GABA B Receptor Antagonists. IX The Synthesis of 3-Amino-3-(4-chlorophenyl)propanoic Acid, 2-Amino-2-(4-chlorophenyl)ethylphosphonic Acid and 2-Amino-2-(4-chlorophenyl)ethanesulfonic Acid

1997 ◽  
Vol 50 (6) ◽  
pp. 523 ◽  
Author(s):  
Giovanni Abbenante ◽  
Robert Hughes ◽  
Rolf H. Prager
Keyword(s):  
Carboxylic Acid ◽  
Phosphonic Acid ◽  
Sulfonic Acid ◽  
Gabab Receptor ◽  
Propanoic Acid ◽  
Receptor Antagonists ◽  
Sulfonic Acids ◽  
Ethanesulfonic Acid

This paper describes the synthesis of 3-amino-3-(4-chlorophenyl)propanoic acid and the corresponding phosphonic and sulfonic acids, lower homologues of baclofen, phaclofen and saclofen respectively. The chlorinated acids were all weak specific antagonists of GABA at the GABAB receptor, with the sulfonic acid (pA2 4·0) being stronger than the phosphonic acid (pA2 3·8) and carboxylic acid (pA2 3·5).

Potential GABAB Receptor Antagonists. II. Synthesis of 1-[2-Amino-1-(4-chlorophenyl)ethyl]-3-oxo-1,3-dihydroisobenzofuran-1-carboxylic Acid

1989 ◽  
Vol 42 (5) ◽  
pp. 731 ◽  
Author(s):  
WK Janowski ◽  
RH Prager
Keyword(s):  
Carboxylic Acid ◽  
Michael Addition ◽  
Gabab Receptor ◽  
Receptor Antagonists ◽  
Polar Solvents ◽  
Gabab Receptor Antagonists

Michael addition of methyl 3-oxo-1,3-dihydroisobenzofuran-1-carboxylate to nitrostyrenes is catalysed by amine bases. In non-polar solvents, the use of both enantiomers of ψ-ephedrine as base (0.1 equiv.) leads to both enantiomers , respectively, of a single diastereoisomer. When the reaction mixture is heated, the reaction is neither diastereoselective nor enantioselective. The products have been converted into the potential GABAB analogue 1-[2-amino-1-(4-chlorophenyl )ethyl]-3-oxo-1,3-dihydroisobenzofuran-1-carboxylic acid.

Potential GABAB Receptor Antagonists. IV. Synthesis of 1-[2-Amino-1-(4-chlorophenyl)ethyl]-3-oxo-1,3-dihydro-isobenzofuran-1-yl phosphonic Acid

1991 ◽  
Vol 44 (3) ◽  
pp. 477 ◽  
Author(s):  
WK Janowski ◽  
RH Prager
Keyword(s):  
Phosphonic Acid ◽  
Gabab Receptor ◽  
Receptor Antagonists ◽  
Michael Adducts ◽  
Subsequent Conversion ◽  
Diastereoselective Addition ◽  
Gabab Receptor Antagonists

The diastereoselective addition of dimethyl 3-oxo-1,3-hydroisobenzofuran-1-ylphosphonate to nitrostyrene and p- chloronitrostyrene is reported, as is the subsequent conversion of the Michael adducts into 1-[2-amino-1-phenylethyl]-3-oxo-1,3-dihydroisobenzofuran-1-ylphosphonic acid, and 1-[2-amino-1-(4-chlorophenyl)ethyl]-3-oxo-1,3 dihydroisobenzofuran-1-ylphosphonic acid respectively.

Potential GABAB Receptor Antagonists. VI. The Synthesis of Saclofen and Other Sulfonic Acid Derivatives

1992 ◽  
Vol 45 (11) ◽  
pp. 1801 ◽  
Author(s):  
G Abbenante ◽  
RH Prager
Keyword(s):  
Sulfonic Acid ◽  
Gabab Receptor ◽  
Sulfonyl Chloride ◽  
Radical Addition ◽  
Hydroxy Derivative ◽  
Thioacetic Acid ◽  
Receptor Antagonists ◽  
Specific Antagonist ◽  
Gabab Receptor Antagonists

Saclofen, 3-amino-2-(4chlorophenyl) propanesulfonic acid (3), has been synthesized by two routes. Attempts to hydrogenolyse or dehydrate the 2-hydroxy derivative were unsuccessful, however. Radical sulfonation of 3-amino-1-bromo-2-(4-chlorophenyl) propene gave 3-amino-2- (4-chlorophenyl)propene-1-sulfonic acid (6) which was readily reduced to (3). Alternatively, 2-(4-chlorophenyl)-3-phthalimidopropene underwent radical addition of thioacetic acid, and oxidation of the product to the sulfonyl chloride and hydrolysis gave (3). The corresponding sulfonamide (4) was also prepared. The acid (3) is a powerful specific antagonist of GABA at the GABAB receptor, while (4) and (6) are only weak antagonists.

Effect of surface acidity on the catalytic activity and deactivation of supported sulfonic acids during dehydration of methanol to DME

2020 ◽  
Vol 44 (39) ◽  
pp. 16810-16820
Author(s):  
Rosanna Viscardi ◽  
Vincenzo Barbarossa ◽  
Daniele Mirabile Gattia ◽  
Raimondo Maggi ◽  
Giovanni Maestri ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Sulfonic Acid ◽  
Water Resistance ◽  
Surface Acidity ◽  
Acid Catalyst ◽  
Acid Sites ◽  
Sulfonic Acids ◽  
Effect Of Surface

Superiorty of the supported sulfonic acid catalyst in terms of the water resistance and efficiency of the acid sites compared to the commercial reference.

scholarly journals Enkephalin analogs containing amino sulfonic acid and amino phosphonic acid residues at position 5

FEBS Letters ◽  
1980 ◽  
Vol 117 (1-2) ◽  
pp. 308-310 ◽  
Author(s):  
S. Bajusz ◽  
A.Z. Rónai ◽  
J.I. Székely ◽  
A. Turán ◽  
A. Juhász ◽  
...  
Keyword(s):  
Phosphonic Acid ◽  
Sulfonic Acid
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