Process for producing amine-boranes

A method for producing an amine borane which comprises:

• (i) charging a reaction vessel with an amine;
• (ii) adding an alkali metal borohydride to said amine contained in said reaction vessel;
• (iii) thereafter concurrently adding a weak acid and water to said reaction vessel in an amount and for a time sufficient to produce the desired amine borane;
• (iv) thereafter adding aqueous alkali metal hydroxide to the reaction mixture produced by step (iii);
• (v) adding water to the product of step (iv) to provide an amine borane containing an upper layer and an aqueous lower layer;
• and
• (vi) separating said amine borane containing upper layer.

A method for producing pyridine-borane which comprises:

• (i) charging a reaction vessel with pyridine;
• (ii) adding an alkali metal borohydride to said pyridine contained in said reaction vessel;
• (iii) thereafter concurrently adding a weak acid and water to said reaction vessel in an amount and for a time sufficient to produce the pyridine-borane;
• (iv) thereafter adding aqueous alkali metal hydroxide to cause the reaction mixture produced by step (iii) to form an upper pyridine-borane containing layer and a lower aqueous layer;
• (v) separating said upper pyridine-borane containing layer and agitating said separated upper layer with a solid alkali metal hydroxide;
• (vi) thereafter removing unreacted pyridine from said upper layer;
• and
• (vii) recovering a substantially water white pyridine-borane product having a purity of 92% to 96% as determined by iodometric titration said product being recovered in approximately 80% yield, corrected for purity, based on said alkali metal borohydride added in step (ii).