4-Hydroxybenzoic Acid → Benzyl 4-Hydroxybenzoate

Participants

Reaction Steps

A neat solution of 18.6 mL (15g, 118.8 mmol) of 1,3-diisopropylcarbodiimide and 60 mg (0.6 mmol) of cuprous chloride was placed under a blanket of argon and then cooled to 0° C. in an ice bath. To this reaction mixture was added dropwise (via syringe) 12.9 mL (13.5 g, 124.7 mmol) of benzyl alcohol. The resultant green reaction mixture was allowed to stir at 0° C. overnight, filtered through celite (rinsing with hexane) and the filtrate then Kugelrohr distilled (105° C., 2 mm Hg) to give 2-benzyl-1,3-diisopropyl isourea as a clear, colorless oil. To a solution of 650 mg (4.7 mmol) of 4-hydroxybenzoic acid in 20 mL of tetrahydrofuran was added 1.1 g (4.7 mmol) of 2-benzyl-1,3-diisopropyl isourea. The reaction mixture was allowed to stir at ambient temperature overnight, filtered (rinsing with tetrahydrofuran) and then concentrated in vacuo. Purification by flash chromatography (silica, 25% ethyl acetate in hexane) gave the title compound as a white solid. PMR (CDCl3): δ 5.22 (1 H, s), 5.35 (2 H, s), 6.87 (2 H, d, J=8.8 Hz), 7.34-7.50 (5 H, m), 8.01 (2 H, d, J=8.8 Hz).

Provenance & Evidence