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Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, [5] is an inorganic compound with the formula Na B H 4 (sometimes written as Na[BH 4]). It is a white crystalline solid, usually encountered as an aqueous basic solution .
Bases are proton acceptors; a base will receive a hydrogen ion from water, H 2 O, and the remaining H + concentration in the solution determines pH. A weak base will have a higher H + concentration than a stronger base because it is less completely protonated than a stronger base and, therefore, more hydrogen ions remain in its solution.
At 25 °C (77 °F), solutions of which the pH is less than 7 are acidic, and solutions of which the pH is greater than 7 are basic. Solutions with a pH of 7 at 25 °C are neutral (i.e. have the same concentration of H + ions as OH − ions, i.e. the same as pure water). The neutral value of the pH depends on the temperature and is lower than 7 ...
At low pH values, it efficiently reduces aldehydes and ketones. [7] As the pH increases, the reduction rate slows and instead, the imine intermediate becomes preferential for reduction. [ 7 ] For this reason, NaBH 3 CN is an ideal reducing agent for one-pot direct reductive amination reactions that don't isolate the intermediate imine.
The pH at the end-point depends mainly on the strength of the acid, pK a. The pH at the end-point is greater than 7 and increases with increasing concentration of the acid, T A, as seen in the figure. In a titration of a weak acid with a strong base the pH rises more steeply as the end-point is approached. At the end-point, the slope of the ...
Lithium borohydride (LiBH 4) is a borohydride and known in organic synthesis as a reducing agent for esters.Although less common than the related sodium borohydride, the lithium salt offers some advantages, being a stronger reducing agent and highly soluble in ethers, whilst remaining safer to handle than lithium aluminium hydride.
Sodium borohydride can, under some circumstances, be used for ester reduction, especially with additives. [ 1 ] Forming aldehydes from carboxylic acid derivatives is challenging because weaker reducing agents (NaBH 4 ) are often very slow at reducing esters and carboxylic acids, whereas stronger reducing agents (LiAlH 4 ) immediately reduce the ...
BMS is commercially available at much higher concentrations than its tetrahydrofuran counterpart (10 M) and does not require sodium borohydride as a stabilizer, which could result in undesired side reactions. [2] In contrast, BH 3 ·THF requires sodium borohydride to inhibit reduction of THF to tributyl borate (B(OCH 2 CH 2 CH 2 CH 3) 3). [2]