Methylparaben → methyl (S)-4-(2-amino-1-propoxy)benzoate

Participants

Reaction Steps

To a cooled (0° C.) solution of (S)-2-(N-tert-butoxycarbonylamino)-1-propanol (1.02 g, 5.82 mmol), methyl 4-hydroxybenzoate (0.89 g, 5.85 mmol), and Ph3P (1.98 g, 7.55 mmol) in THF (20 mL) was added diisopropyl azodicarboxylate (DIAD) (1.49 mL, 7.57 mmol), and the resulting mixture was heated under reflux overnight. The solution was evaporated and the residue was dissolved in CH2Cl2 (20 mL) and TFA (10 mL). The mixture was stirred at room temp for 1.5 hr. The solution was concentrated in vacuo and the residue was treated with sat. NaHCO3. The mixture was extracted with CHCl3, washed with brine, dried over Na2SO4 and evaporated. The residue was purified by column chromatography on silica-gel with CHC3:MeOH (50:1, v/v) to give 480 mg (2 steps 39%) methyl (S)-4-(2-amino-1-propoxy)benzoate as a pale yellow oil. 1H-NMR (CDCl3) δ1.19 (d, 3 H, J=6.4 Hz), 3.35-3.39 (m, 1 H), 3.72-3.76 (m, 1 H), 3.89 (s, 3 H), 3.90-3.94 (m, 1 H), 6.92 (d, 2 H, J=8.8 Hz), 7.99 (d, 2 H, J=8.8 Hz).

Provenance & Evidence