合成路线1

3-Amino-2-naphthoic acid (I) is diazotized with NaNO2/HCl, and the obtained diazonium salt is then isolated as the corresponding tetrafluoroborate (II). Subsequent thermal decomposition of the diazonium tetrafluoroborate (II) in refluxing xylene leads to 3-fluoro-2-naphthoic acid (III). After chlorination of (III) with oxalyl chloride, the resultant acid chloride (IV) is treated with NaN3 to produce the acyl azide (V), which undergoes Curtius rearrangement to the amine (VI) in refluxing aqueous DMF. Diazotization of (VI), followed by reduction with SnCl2 gives rise to hydrazine (VII). Treatment of ethyl 2,4-dioxovalerate (VIII) with O-methylhydroxylamine gives oxime (IX), which is then condensed with hydrazine (VII), yielding the intermediate pyrazole (X).