Acetic Acid → Ethyl 4-(dibenzylamino)-2-ethylcyclopentanecarboxylate

Participants

Reaction Conditions

Reaction Steps

A round bottom flask was charged with ethyl 2-ethyl-4-oxocyclopentanecarboxylate (95.9 g, 521 mmol) and DCE (1.8 L). The solution was cooled to about 0° C. and AcOH (45 mL, 780 mmol) and dibenzylamine (120 mL, 625 mmol) were added dropwise, resulting in the formation of a thick suspension. The reaction mixture was warmed to about 10° C. and additional DCE (500 mL) was added. Sodium triacetoxyborohydride (166 g, 781 mmol) was added portionwise and the reaction mixture was stirred at ambient temperature for about 20 h. The reaction mixture was slowly poured into stirred saturated aqueous NaHCO3 (1.5 L), followed by the portionwise addition of solid NaHCO3 (175 g). The mixture was stirred for about 2 h and the organic layer was separated, dried over anhydrous Na2SO4, and coned under reduced pressure. The crude yellow oil was purified by silica gel chromatography eluting with 0-20% EtOAc in heptane to yield ethyl 4-(dibenzylamino)-2-ethylcyclopentanecarboxylate (136.6 g, 72%) as a white solid: LC/MS (Table 1, Method a) Rt=3.26 min; MS m/z: 366 (M+H)+

Provenance & Evidence