Sodium borohydride in carboxylic acid media: a phenomenal reduction system

1998 ◽  
Vol 27 (6) ◽  
pp. 395 ◽  
Author(s):  
Gordon W. Gribble
Keyword(s):  
Carboxylic Acid ◽  
Sodium Borohydride ◽  
Acid Media ◽  
Reduction System

Cu(II)/sodium borohydride-based electrocatalytic system for reduction and dyeing of indigo

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaoyan Li ◽  
Zhihui Zhang ◽  
Jiming Yao ◽  
MengQian Wang ◽  
Na Yang
Keyword(s):  
Sodium Borohydride ◽  
Sewage Treatment ◽  
Integrated Analysis ◽  
Borohydride Reduction ◽  
Electrocatalytic Reduction ◽  
Content Type ◽  
Dyeing Performance ◽  
Sodium Hydrosulfite ◽  
Reduction System ◽  
Sodium Borohydride Reduction

Purpose To improve the problems as the heavy burden of sewage treatment and environmental pollution caused by the traditional sodium hydrosulfite reduction dyeing of indigo, this study aims to carry out the direct electrochemical reduction dyeing for indigo with the eco-friendly Cu(II)/sodium borohydride reduction system under normal temperature and pressure conditions. Design/methodology/approach The electrochemical behavior of Cu(II)/sodium borohydride reduction system was investigated by cyclic voltammetry. And, the dyeing performance of the Cu(II)/sodium borohydride reduction system was developed by optimizing the concentration of copper sulfate in the anode electrolyte, applied voltage and reduction time via single-factor and orthogonal integrated analysis. Findings The dyeing performance of the Cu(II)/sodium borohydride reduction system is superior to that of the traditional reduction dyeing with sodium hydrosulfite. In the case of the optimized condition, the soaping fastness and dry/wet rubbing fastness of the dyed fabric in the two reduction dyeing processes were basically comparable, the K/S value of electrocatalytic reduction of indigo by Cu(II)/NaBH4 is 11.81, which is higher than that obtained by traditional sodium hydrosulfite reduction dyeing of indigo. Originality/value The innovative electrocatalytic reduction system applied herein uses sodium borohydride as the hydrogen source combined with Cu(II) complex as the catalyst, which can serve as a medium for electron transfer and active the dye molecule to make it easier to be reduced. The electrochemical dyeing strategy presented here provides a new idea to improve the reduction dyeing performance of indigo by sodium borohydride.

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.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document