Sodium Bicarbonate → tert-butyl (1S,2S,4S)-4-(dibenzylamino)-2-methylcyclohexylcarbamate tert-butyl (1R,2R,4R)-4-(dibenzylamino)-2-methylcyclohexylcarbamate

Participants

Reaction Steps

To (1S,3S,4S)—N1,N1-dibenzyl-3-methylcyclohexane-1,4-diamine/(1R,3R,4R)—N1,N1-dibenzyl-3-methylcyclohexane-1,4-diamine (1.851 g, 6 mmol) in dioxane (200 mL) and saturated aqueous NaHCO3 solution (100 mL) was added BOC-anhydride (2.438 mL, 10.50 mmol), dissolved in dioxane (˜5 mL). The resulting white suspension was stirred vigorously for 18 hr. The mixture was extracted with DCM (4×300 mL) and EtOAc (1×100 mL). The combined organic layers were concentrated in vacuo. The resulting residue was dissolved in EtOAc, washed with brine, dried over Na2SO4, filtered of and concentrated in vacuo. The resulting residue was purified by column chromatography [SiO2, 120 g, DCM/MeOH=100/0 to 95/5]. Fractions containing product were combined, concentrated in vacuo providing tert-butyl (1S,2S,4S)-4-(dibenzylamino)-2-methylcyclohexylcarbamate/tert-butyl (1R,2R,4R)-4-(dibenzylamino)-2-methylcyclohexylcarbamate. Yield: 778 mg. LCMS (m/z): 409.2 [M+H]+; Retention time=0.84 min.

Provenance & Evidence