2,3-dihydro-7-hydroxy-8-propyl-4H-1-benzopyran-4-one → HCID 67780161, compound

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Reaction Steps

Using the procedure of example 11 and starting with 0.26 g (1.3 mmol) of 2,3-dihydro-7-hydroxy-8-propyl-4H-1-benzopyran-4-one and 0.76 g (1.3 mmol) of (E)-4-[3-(3-methoxy-3-oxo-1-propenyl)-4-[6-[(methylsulfonyl)oxy]hexyl]phenoxy]butanoic acid methyl ester (from example 113), (E)-4-[3-(2-carboxyethenyl)-4-[6[(3,4-dihydro-4-oxo-8-propyl-2H-1-benzopyran-7-yl)oxy]hexyl]phenoxy]butanoic acid methyl ester was obtained in 95% yield (0.36g) as a colorless oil which crystallized on standing. Recrystallization from ethyl acetate-hexane gave 0.51 g (69%) of a colorless solid, mp 65°-66° C. A 0.2 g (0.35 mmol) sample of diester prepared in this way was saponified with 2 mL of 3N aqueous lithium hydroxide in 10 mL of tetrahydrofuran, at room temperature, for 22 hr. Work-up as in example 4 gave a crude acid product which was purified by chromatography on silica gel (toluene-ethyl acetate containing 2% acetic acid) and recrystallization from acetonitrile. There was obtained 0.1 g (53%) of (E)-4-[3-(2-carboxyethenyl)-4-[6-[(3,4-dihydro-4-oxo-8-propyl-2H-1-benzopyran-7-yl)oxy]hexyl]phenoxy]butanoic acid as an off-white solid mp 140°-143° C.

Provenance & Evidence