2,3-dihydro-7-hydroxy-8-propyl-4H-1-benzopyran-4-one → HCID 54554587, compound

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Reaction Steps

Using the procedure of example 11 and starting with 0.28 g (1.4 mmol) of 2,3-dihydro-7-hydroxy-8-propyl-4H-1-benzopyran-4-one and 0.7 g (1.4 mmol) of 2-[5-(methylsulfonyl)oxypentyloxy]-5-(3-ethoxycarbonylpropoxy)benzenepropanoic acid ethyl ester (from example 46), 5-(3-ethoxycarbonylpropoxy)-2-[5-[(3,4-dihydro-4-oxo-8-propyl-2H-1-benzopyran-7-yl)oxy]pentyloxy]benzenepropanoic acid ethyl ester was obtained in 83.6% yield (0.7 g) as a solid. This diester (1.17 mmol) was saponified with 3 mL of 3N aqueous lithium hydroxide in 25 mL of tetrahydrofuran, at room temperature, for 37 hr. Work-up as in example 4gave a light-brown oily acid which was flash-chromatographed on silica gel, eluting with 95:5:1 chloroform-methanol-acetic acid. There was obtained 0.39 g (61.5%) of pure 5-(3-carboxypropoxy)-2-[5-[(3,4-dihydro-4-oxo-8-propyl-2H-1-benzopyran-7-yl)oxy]pentyloxy] benzenepropanoic acid. Recrystallization from hexane-ethyl acetate gave a colorless solid, mp 119°-124° C.

Provenance & Evidence