2,3-dihydro-7-hydroxy-8-propyl-4H-1-benzopyran-4-one → HCID 53861097, 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 0.66 g (1.4 mmol) of 2-[[5-[(methylsulfonyl)oxy]pentyl]oxy]-5-(5-methoxy-5-oxopentyloxy)benzenepropanoic acid methyl ester (from example 57), 5-(5-methoxy-5-oxopentyloxy)-2-[5-[(3,4-dihydro-4-oxo-8-propyl-2H-1-benzopyran-7-yl)oxy]pentyloxy]benzenepropanoic acid methyl ester was obtained in 61% yield (0.5 g) as a colorless solid. This diester (0.85 mmol) was saponified with 3 mL of 3N aqueous lithium hydroxide in 20 mL of tetrahydrofuran, at room temperature, for 24 hr. Work-up as in example 4 gave a crystalline acid which was flash-chromatographed on silica gel, eluting with 95:5:1 chloroform-methanol-acetic acid. There was obtained 0.44 g (93%) of pure 5-(4-carboxybutoxy)-2-[5-[(3,4-dihydro-4-oxo- 8-propyl-2H-1-benzopyran-7-yl)oxy]pentyloxy]benzenepropanoic acid. Recrystallization from ethyl acetate gave 0.35 g (74%) of a colorless solid, mp 138°-139° C.

Provenance & Evidence