To a stirred solution of Boc-DAB-OH (436 mg, 2.0 mmol) in 15 mL of methanol/H₂O mixture (5:2) was added benzaldehyde (204 µL, 2.0 mmol) and Pic-BH₃ (214 mg, 2.00 mmol). The solution was stirred at room temperature for four hours. After four hours the reaction was cooled to 0 °C and excess aqueous formaldehyde solution (37%) was added (1.6 mL). Caution: an exothermic reaction accompanied by gas evolution occurs on formaldehyde addition. The reaction was stirred for one hour and allowed to warm to room temperature. Volatiles were removed in vacuo and the crude residue was purified by silica gel chromatography (0-10% MeOH:DCM gradient, product Rf 0.45) to give the N-benzyl-N­-methylated intermediate as an off white solid (72% Yield, 460 mg, 1.43 mmol). The intermediate was dissolved in 25 mL of an isopropyl alcohol/H₂O mixture (1:5) and 43 mg of 10% Pd/C was added. The reaction mixture was stirred vigorously under a H₂ atmosphere for 12 hours. After 12 hours, total debenzylation was confirmed by LCMS. H₂ was purged from the reaction mixture with N₂ and the catalyst was removed by filtration through a plug of celite. The celite pad was washed with isopropyl alcohol (2 x 10 mL) and added to the filtrate. Volatiles were removed from the combined filtrates in vacuo to give quantitative isolation of the target mono N­-methylated product (Yield >95%, 332 mg, 1.43 mmol).