Pyridine → [(4E)-2-[[4-[(2,4-dioxo-1,3-thiazolidin-5-yl)methyl]phenoxy]methyl]-2,5,7,8-tetramethyl-4-(pyridine-3-carbonyloxyimino)-3H-chromen-6-yl] pyridine-3-carboxylate

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Reaction Steps

A mixture of 1 g of 5-{4-[6-hydroxy-4-(E)-hydroxyimino-2,5,7,8-tetramethylchroman-2-ylmethoxy ]benzyl}thiazolidine-2,4-dione (prepared as described in Example 13), 1.1 g of nicotinoyl chloride hydrochloride, 12 ml of pyridine and 12 ml of dimethylformamide was allowed to stand for 6 days at room temperature, after which it was heated for 8 hours at 60°-80° C. An aqueous solution of potassium carbonate and ethyl acetate were added to the reaction mixture. The organic layer was separated and dried over anhydrous sodium sulfate. The solvent was distilled off, and the residue was purified by silica gel column chromatography eluted with a 2:3 by volume mixture of hexane and ethyl acetate, followed by preparative thin layer silica gel chromatography (developing solvent, hexane:ethyl acetate=1.10 by volume), to give the title compound, softening at 123°-130° C.

Provenance & Evidence