Sulfuric Acid → HCID 19922128, compound

Participants

Reaction Steps

A mixture of 0.86 g (1.39 mmol) of 2-[[5-[(3,4-dihydro-4-oxo-8-propyl-2H-1-benzopyran-7-yl)oxy]pentyl]oxy]-7-(2-ethoxy-2-oxoethoxy)-1-naphthalenepropanoic acid ethyl ester from the preceding example, 0.177 g (4.21 mmol) of lithium hydroxide monohydrate, 10.1 mL of tetrahydrofuran, and 10.1 mL of water was stirred at room temperature for 41.5 hr. A second saponification was carried out with 0.188 g (0.3 mmol) of the starting ester, 38 mg (0.9 mmol) of lithium hydroxide monohydrate, 2.2 mL of tetrahydrofuran and 2.2 mL of water. After combining the two reaction mixtures, 30 mL of 3N aqueous sulfuric acid was added, and the mixture was worked-up with ethyl acetate in the usual manner. The crude product was crystallized from hexane-ethyl acetate to give 0.803 g (84.3%) of the title compound as an off-white solid, mp 175°-177.5° C.

Provenance & Evidence