Diisopropylethylamine → (S)-7-[3-[[(2,3-Dihydro-7-methoxy-1,4-benzodioxin-2-yl)methyl]amino]propoxy]-2H-1-benzopyran-2-one

Participants

Reaction Conditions

Reaction Steps

(S)-2,3-Dihydro-7-methoxy-1,4-benzodioxin-2-methanamine hydrochloride (11.5 g, 49.8 mmole), 7-(3-bromopropoxy)coumarin (14.2 g, 50.0 mmole), and diisopropylethylamine (12 ml, 68.9 mmole) were combined in 350 ml of DMF and heated at 90° C. for 24 hours under a nitrogen atmosphere. The solvent was then removed in vacuum and replaced with 300 ml of dichloromethane. Upon addition of an equal volume of saturated aqueous sodium bicarbonate, a white solid precipitated. This was filtered and redissolved in 550 ml of warm methanol and 35 ml of 4N isopropanolic HCl was added. The solution was boiled on a hot plate and the solvent gradually replaced with isopropanol. Upon cooling, 0.54 g of the title compound precipitated as a white solid, monohydrochloride, quarter hydrate, m.p. 225°-227° C. Subsequent crops yielded as additional 6.1 g of product.

Provenance & Evidence