Triphenylphosphine → 4-Methoxy-3-(2-morpholin-4-yl-ethoxy)benzoic acid methyl ester

Participants

Reaction Steps

To stirred solution of methyl 3-hydroxy-4-methoxybenzoate (2.00 g, 11.0 mmol), 4-(2-hydroxyethyl)morpholine (1.58 g, 12.0 mmol) and triphenylphosphine (3.17 g, 12.1 mmol) in ethyl acetate (60 mL) was added, dropwise, diethyl azodicarboxylate (1.9 mL, 12.1 mmol). The reaction was allowed to proceed overnight and then diluted with additional ethyl acetate and extracted with 1 N aqueous hydrochloric acid. The aqueous layer was washed with ethyl acetate, basified with concentrated ammonium hydroxide and then extracted with ethyl acetate. The organic extract was dried (sodium sulfate) and concentrated to afford 3.25 g of a 92:8 mixture of product (95%) and diethyl hydrazinedicarboxylate as an amber oil. This material was used without further purification in the next step: 1H NMR (CDCl3) δ 7.69 (dd, J=8.4, 2.0 Hz, 1H), 7.58 (d, J=2.0 Hz, 1H), 6.89 (d, J=8.4 Hz, 1H), 4.20 (t, J=6.0 Hz, 2H), 3.91 (s, 3H), 3.89 (s, 3H), 3.77-3.72 (m, 4H), 2.87 (t, J=6.0 Hz, 2H), 2.65-2.57 (m, 4H) ppm.

Provenance & Evidence