2-Naphthalenecarboxylic acid, 6-(diMethylaMino)-4-hydroxy-, Methyl ester synthesis

Yield:263026-75-1 85 g

Reaction Conditions:

with sulfuric acid for 5 h;Reflux;

Steps:

Synthesis of methyl 6-(dimethylamino)-4-hydroxy-2-naphthoate (6)

Compound 5 (100g, 0.43mol, 1eq) dissolved in 2L methanol and slowly added 25mL concentrated H₂SO₄ inside the reaction mixture and reflux for 5h. After that methanol was evaporated on rotary and reaction mixture was neutralized using NaOH, extracted with ethyl acetate and water (due to low solubility product, ethyl acetate and water ratio was kept 1.5:1), dried the ethyl acetate layer with MgSO₄ evaporated the excess solvent on rotary left behind solid product of 6, yield (85g, 80%). ¹H NMR (CDCl₃, ppm): δ 3.13 (s, 6H), 3.94 (s, 3H), 6.05 (s, 1H), 7.15 (s, 1H), 7.20 (d, 1H), 7.75 (s, 1H), 7.75 (d, 1H), 8.08 (s, 1H).

References:

Kim, Moon-Hwan;Saleem, Muhammad;Seo, Ji-Su;Choi, Chang-Shik;Lee, Ki Hwan [Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy,2015,vol. 136,# PC,p. 1291 - 1297]