scholarly journals A General Stereoselective Approach to 1,2,4-Triazepane-3-thiones/ones via Reduction or Reductive Alkylation of 2,4,5,6-Tetrahydro-3H-1,2,4-triazepine-3-thiones/ones

Proceedings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 14
Author(s):  
Anastasia A. Fesenko ◽  
Anatoly D. Shutalev
Keyword(s):  
Carboxylic Acid ◽  
Sodium Borohydride ◽  
Reductive Alkylation ◽  
Sodium Cyanoborohydride

A general stereoselective approach to previously unknown 1,2,4-triazepane-3-thiones/ones based on reduction or reductive alkylation of readily available 2,4,5,6-tetrahydro-3H-1,2,4-triazepine- 3-thiones/ones has been developed. The approach involved treatment of tetrahydrotriazepines with sodium cyanoborohydride in MeOH at pH 3 or with sodium borohydride and excess of carboxylic acid in tetrahydrofuran to give 1-unsubstituted or 1-alkyl-substituted 1,2,4-triazepane-3- thiones/ones, respectively. The latter were also prepared by reaction of 1-unsubstituted 1,2,4- triazepane-3-thiones/ones with sodium cyanoborohydride and aldehyde in MeOH in the presence of AcOH.

Synthesis and Antibacterial Activity of Some 3-Hydroxyquinolones

1992 ◽  
Vol 57 (1) ◽  
pp. 188-193 ◽  
Author(s):  
Stanislav Rádl ◽  
Magda Janichová
Keyword(s):  
Antibacterial Activity ◽  
Carboxylic Acid ◽  
Hydroxy Group ◽  
Sodium Borohydride ◽  
Selenium Dioxide ◽  
Prolonged Heating

A reductive decarboxylation of 7-chloro-1-ethyl-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (Id) with sodium borohydride provided the respective 1,2,3,4-tetrahydro derivative Va, which was treated with selenium dioxide to give product of dehydrogenation VIa. 3-Acetyl-1-ethyl-1,4-dihydroquinolin-4-ones VIb and VIc were oxidized with 3-chloroperoxybenzoic acid to the respective 3-hydroxyderivatives IIIa and IIIb. Compound IIIb was benzylated on a hydroxy group at position 3 to corresponding 3-benzyloxy derivative VIf which after prolonged heating with N-methylpiperazine in a sealed tube provided directly 3-hydroxy-7-(4-methyl-1-piperazinyl) derivative IIIc.

Catalyst-Free One-Pot Reductive Alkylation of Primary and Secondary Amines and N,N-Dimethylation of Amino Acids Using Sodium Borohydride in 2,2,2-Trifluoroethanol

Synthesis ◽  
2010 ◽  
Vol 2011 (03) ◽  
pp. 490-496 ◽  
Author(s):  
Mahmood Tajbakhsh ◽  
Rahman Hosseinzadeh ◽  
Heshmatollah Alinezhad ◽  
Somayeh Ghahari ◽  
Akbar Heydari ◽  
...  
Keyword(s):  
Amino Acids ◽  
Sodium Borohydride ◽  
Secondary Amines ◽  
Reductive Alkylation ◽  
One Pot ◽  
Catalyst Free ◽  
Primary And Secondary Amines

Synthesis of l,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acids and homologous pyridine and azepine analogues thereof

1982 ◽  
Vol 60 (18) ◽  
pp. 2295-2312 ◽  
Author(s):  
Humberto Carpio ◽  
Edvige Galeazzi ◽  
Robert Greenhouse ◽  
Angel Guzmán ◽  
Esperanza Velarde ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
Acid Derivative ◽  
Sodium Borohydride ◽  
Acid Ester ◽  
Keto Acid ◽  
Acid Salt ◽  
Keto Ester ◽  
Acetic Acid Esters ◽  
Acid Esters

Several syntheses of the previously unknown 1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acid and various 5- and 6-substituted derivatives thereof have been devised. Some of these processes have been extended to the heretofore unreported 5,6,7,8-tetrahydropyrrolo[1,2-a]pyridine-8-carboxylic acid and 5,6,7,8-tetrahydro-9H-pyrrolo[1,2-a]azepine-9-carboxylic acid derivatives.Two new processes were developed for the conversion of pyrroles into the corresponding pyrrol-2-acetic acid esters. Both processes were based on the use of the readily available ethoxalylpyrrole derivatives as the starting material. One sequence involved saponification of the α-keto ester, followed by Wolff–Kishner reduction of the crude α-keto acid salt and subsequent esterification of the acetic acid derivative thus produced. The second synthesis commenced with reduction of the 2-ethoxalpyrrole with sodium borohydride to the α-hydroxy ester, which was further reduced to the acetic acid ester with an equimolar mixture of triphenylphosphine and triphenylphosphine diiodide.

An improved method for reductive alkylation of amines using titanium(IV) isopropoxide and sodium cyanoborohydride

1990 ◽  
Vol 55 (8) ◽  
pp. 2552-2554 ◽  
Author(s):  
Ronald J. Mattson ◽  
Kahnie M. Pham ◽  
David J. Leuck ◽  
Kenneth A. Cowen
Keyword(s):  
Improved Method ◽  
Reductive Alkylation ◽  
Sodium Cyanoborohydride

Nuclear analogs of β-lactam antibiotics. I. Synthesis of O-2-isocephams

1977 ◽  
Vol 55 (3) ◽  
pp. 468-483 ◽  
Author(s):  
Terrence William Doyle ◽  
Bernard Belleau ◽  
Bing-Yu Luh ◽  
Carrado F. Ferrari ◽  
Michael Patrick Cunningham
Keyword(s):  
Schiff Base ◽  
Carboxylic Acid ◽  
Total Synthesis ◽  
Sodium Borohydride ◽  
Boron Trifluoride ◽  
Cycloaddition Reaction ◽  
Phenoxyacetic Acid ◽  
Azido Group ◽  
Borohydride Reduction ◽  
Sodium Borohydride Reduction

The preparation by total synthesis of a saturated cephalosporin analog 7-β-phenoxyacet-amido-3-ethoxy-O-2-isocepham-4-α-carboxylic acid 30, is described. Compound 30 was prepared via cycloaddition of azidoacetyl chloride to the cinnamylidene Schiff base of ethyl 2-amino-3, 3-diethoxypropionate 13b to give the cis-3-azido-4-styryl β-lactam 15b. Ozonolysis of 15b followed by sodium borohydride reduction gave the alcohol 18b. Boron trifluoride treatment of 18b gave ethyl 7-β-azido-3- β-ethoxy-O-2-isocephem-4-carboxylate 27. Reduction of the azido group followed by coupling with phenoxyacetic acid and saponification of the ester gave 30. The mechanism of the cycloaddition reaction and the stereochemical assignments are also discussed.

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