2,3-dihydro-7-hydroxy-8-propyl-4H-1-benzopyran-4-one → 5-chloro-2-[5-[(3,4-dihydro-4-oxo-8-propyl-2H-1-benzopyran-7-yl)oxy]pentyloxy]benzenepropanoic acid

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Reaction Steps

Using the procedure of example 4,5-chloro-2-[5-[(3,4-dihydro-4-oxo-8-propyl-2H-1-benzopyran-7-yl)oxy]pentyloxy]benzenepropanoic acid methyl ester, a pale-yellow oil, was prepared in quantitative yield starting from 0.62 g (3 mmol) of 2,3-dihydro-7-hydroxy-8-propyl-4H-1-benzopyran-4-one and 1.21 g (3.33 mmol) of 2-[(5-bromopentyl)oxy]-5-chlorobenzenepropanoic acid methyl ester. Saponification using the procedure of example 4 afforded 1.01 g (71%) of 5-chloro-2-[5-[(3,4-dihydro-4-oxo-8-propyl-2H-1-benzopyran-7-yl)oxy]pentyloxy]benzenepropanoic acid as a colorless solid, mp 101°-103° C.

Provenance & Evidence