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With hydrogenchloride; water; In ethanol; at 80℃; for 6h;
The 4-bromo-1-acetamido naphthalene obtained in the first step is dissolved in 100 mL of 95% ethanol, and the mass concentration of 4-bromo-1-acetylaminonaphthalene in the mixed solution is 30%, and the mass concentration is 37% added to the mixed solution. 50mL of concentrated hydrochloric acid, reacted at 80 C for 6h, filtered and dried to give 4-bromo-1-naphthylamine
Acetic anhydride (0.48 ml, 4.95 mmol) wasadded dropwise to a solution of 4-bromonaphthylamine (1 g, 4.5 mmol) in MeOH (8 ml) at0 C for 1 hr. The reaction mixture was refluxed for 1 hrs. The solvent was evaporated andthe residue was poured into water and extracted with ethyl acetate. The organic layer wasdried over anhydrous MgSO4, filtered and concentrated in vacuo to obtain product (95.8 %,skyblue solid). 1H - NMR (400 MHz, CDCl3) delta 8.28 (d, J = 8.1 Hz, 1H), 7.85 (d, J = 7.9 Hz,1H), 7.77 (d, J = 8.2 Hz, 1H), 7.64-7.58 (m, 1H), 7.58 (bs, 1H), 2.33 (s, 3H)