Methylparaben → methyl 4-((2S,4S)-1-tert-butoxycarbonyl-4-(2-naphthyloxy)-2-pyrrolidinylmethoxy)benzoate

Participants

Reaction Steps

To a stirred mixture of (2S,4S)-1-tert-butoxycarbonyl-4-(2-naphthyloxy)-2-pyrrolidinyl methanol (640 mg, 1.86 mmol), methyl 4-hydroxybenzoate (283 mg, 1.86 mmol) and PPh3 (488 mg, 1.86 mmol) in THF (18 ml) was added DIAD (0.37 ml, 1.86 mmol) at room temperature under an atmosphere of nitrogen. The mixture was stirred over night. After removal of the solvent, the resulting residue was chromatographed on silica gel [100 g, n-hexane/EtOAc(2/1)], to give methyl 4-[(2S,4s)-1-tert-butoxycarbonyl-4-(2-naphthyloxy)-2-pyrrolidinyl]methoxybenzoate (830 mg, 93%) as a colorless oil. 1H-NM (CDCl3) δ 1.50 (d, J=8.3 Hz, 9H), 2.34 (m, 1H), 2.53 (d, J=14.2 Hz, 1H), 3.72–3.85 (m, 1H), 3.86 and3.87 (s, 3H, amide isomers), 4.17 (m, 1H), 4.26–4.52 (m, 2H), 5.06 (br, 1H), 6.87 (d, J=8.8 Hz, 1H), 6.94 (d, J=8.8 Hz, 2H), 7.04 (br, 2H), 7.33 (t, J=7.3 Hz, 1H), 7.42 (t, J=7.3 Hz, 1H), 7.64–8.02 (m, 5H).

Provenance & Evidence