Benzoyl isothiocyanate → 1-[2-(6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-benzo[1,2-b]pyran-2-yl)ethyl]-3-benzoylthiourea

Participants

Reaction Steps

A solution of benzoylisothiocyanate (28.0 g) in acetone (200 ml) was added dropwise to a solution of amine (prepared in reference example 3, 34.3 g) in acetone (800 ml). The solution was stirred for 15 hours at room temperature. The reaction solution was evaporated. The residue was purified by column chromatography on silica gel (hexane:ethyl acetate=10:1→4:1→2:1) to give the title compound (32.0 g) having the following physical data.

Provenance & Evidence