Reaction #2446081

Reaction equation

1-((tert-butoxycarbonyl)(cyclohexyl)amino)propan-2-yl 2,4,6-trimethyl-benzoate

formaldehyde

sodium triacetoxyborohydride

acetic acid

→

1-(cyclohexyl(methyl)amino)propan-2-yl-2,4,6-trimethylbenzoate

Solvents

DCM

dioxane-HCl

Conditions

Workup

1. 1
   OtherSolvent was evaporated
2. 2
   workup.DISSOLUTIONCrude solid was dissolved in DCE (10 ml)
3. 3
   OtherThe resultant reaction mixture
4. 4
   workup.STIRRINGwas stirred at rt for 16 hours
5. 5
   Washwashed with 1N NaOH, water and brine
6. 6
   DryingThe organic layer was dried over sodium sulphate
7. 7
   Concentrationconcentrated to dryness
8. 8
   OtherThe crude compound was purified by column chromatography

Procedure

1-((tert-butoxycarbonyl)(cyclohexyl)amino)propan-2-yl 2,4,6-trimethyl-benzoate (1.0 g, 2.48 mmol) was dissolved in dioxane-HCl (15 mL). The reaction mixture was stirred at rt for 2 hours. Solvent was evaporated. Crude solid was dissolved in DCE (10 ml) and formaldehyde (0.34 mL, 3.96 mmol), and sodium triacetoxyborohydride (1.67 g, 7.92 mmol) and acetic acid (0.5 mL) were added at 0° C. The resultant reaction mixture was stirred at rt for 16 hours. The reaction mixture was diluted in DCM and washed with 1N NaOH, water and brine. The organic layer was dried over sodium sulphate and concentrated to dryness. The crude compound was purified by column chromatography to obtain 1-(cyclohexyl(methyl)amino)propan-2-yl-2,4,6-trimethylbenzoate. Yield: 0.6 (76%); 1H NMR (400 MHz, CDCl3) δ 6.82 (s, 2 H), 5.27-5.25 (m, 1 H), 2.64-2.62 (m, 1 H), 2.51-2.46 (m, 1 H), 2.29 (s, 9 H), 2.25 (s, 3 H), 1.75-1.74 (m, 4 H), 1.33-1.31 (d, J=6 Hz, 3 H), 1.18-1.13 (m, 4 H), 1.09-1.03 (m, 1H); LCMS: m/z=317.8 [M+H], RT=2.98 min (Column: X, Program: P1).

Source