A dispersion of 5.4 g of 2-hydroxy-3,6-dichloro carbonylnaphthalene in 20.0 g of dry tetrahydrofuran was added with 14.8 g of n-dodecylamine solution in 30 g of dry tetrahydrofuran and reacted under reflux for 12 hours. To the reaction mixture, 50 g of water was added and the precipitates were collected by filtration, washed with water and thus obtained crystal was washed with 30 g of methanol under reflux. The obtained mixture was cooled to 30° C. and filtrated, washed with methanol and dried to provide 3.3 g of 2-hydroxy-3,6-di-n-dodecylaminocarbonylnaphthalene (decomposition point: 382.9° C.).
