Uses
1,4-dihydroxy-2naphthoic acid methyl ester can be used as organic synthesis intermediate and pharmaceutical intermediate, mainly used in laboratory research and development process and chemical production process.
Synthesis
To a stirred solution of LiOt-Bu (3.20 mmol) in THF (10 mL) at -78 C(CHCl3-liq N2 bath) under an inert atmosphere was added a solutionof isocyanophthalide (1.0 mmol) in THF (5 mL). The resulting yellowish solution was stirred at -78 C for 25 min, after which a solution of a Michael acceptor (1.0-1.5 equiv unless otherwise stated) in THF (5mL) was added. The cooling bath was removed after ca. 1 h at -78 C and the mixture was brought to r.t. over a period of 1 h and stirred fora further 2-6 h. The reaction was then quenched with 10% aq NH4Cl(15 mL) and the resulting solution was concentrated. The residue was diluted with EtOAc (50 mL) and the layers were separated. The aqueous layer was extracted with EtOAc (3 á 25 mL). The combined extracts were washed with H2O (15 mL) and brine (15 mL), dried (anhydNa2SO4), and concentrated under reduced pressure. The crude product was purified by column chromatography (silica gel) or by recrystallizationto obtain the pure product.
