Acetic Acid → Ethyl 4-(4-ethyl-1,4-diazepan-1-yl)benzoate

Participants

Reaction Conditions

Reaction Steps

A solution of ethyl 4-(1,4-diazepan-1-yl)benzoate (0.621 g, 2.5 mmol), acetaldehyde (0.701 mL, 12.50 mmol) and acetic acid (0.286 mL, 5.00 mmol) in tetrahydrofuran (30 mL), methanol (3 mL) was treated with sodium cyanoborohydride (0.393 g, 6.25 mmol) at 20° C. The resulting solution was stirred at 60° C. for 18 h. The reaction mixture was cooled and extra amount of acetaldehyde (2.146 mL, 38 mmol) and sodium triacetoxyborohydride (1.060 g, 5.00 mmol) were added. The reaction was stirred at room temperature for 18 h. The reaction mixture was filtered and evaporated to dryness. The residue was dissolved in 2N HCl (5 ml) and methanol (20 ml). The solution of crude product was purified by ion exchange chromatography, using a SCX column. The desired product was eluted from the column using 7M NH3/MeOH and pure fractions were evaporated to dryness to afford ethyl 4-(4-ethyl-1,4-diazepan-1-yl)benzoate (0.526 g, 76%)

Provenance & Evidence