Patent ID: 7524477

Claim:
A method of preparing B 18 H 22 from boric acid comprising the steps of: (a) preparation of borate ester from boric acid and a primary, secondary, or tertiary alcohol; (b) reducing the borate ester with NaAIH 4 or NaH to form NaBH 4 ; (c) preparing R 4 NBH 4 from NaBH 4 and R 4 NX either in situ or after isolation of NaBH 4 , wherein R is a hydrocarbon and X is an anion; (d) pyrolysis of solid R 4 NBH 4 at about 185 ° C. to form B 10 H 10 2− ; (e) oxidation of B 10 H 10 2− to give B 20 H 18 2−; (f) contacting a solution of B 20 H 18 2− with acidic cation exchange resin; (g) decomposing the resultant acid to give B 18 H 22 ; (h) extracting the residue with solvent in which boric acid byproduct is insoluble; (i) repeating steps (g) and (h) until no further B 18 H 22 is produced; (j) contacting the residues with solvent to dissolve any B 20 H 18 2− containing salts and excluding boric acid byproduct; (k) repeating steps with (f)-(j) at least once; and (l) concentrating the combined hydrocarbon solutions to afford B 18 H 22 .