Synthesis of substituted 1-hydroxy-2-naphthanilides as potential cestodicidal agents.

A series of substituted 1-hydroxy-2-naphthanilides 4--14 has been synthesized by treating 1-hydroxy-2-naphthoic acids 2 with substituted anilines 3. The nitronaphthanilides, on reduction and subsequent treatment with thiophosgene, gave the corresponding substituted 2-naphthanilide isothiocyanates 30--33. Substitution of the chlorine of 8 by various cyclic amines gave 3'-nitro-4'-substituted 1-hydroxy-2-naphthanilides 15--21. Various 3-aryl-4-oxo-2,3-dihydro-1,3-naphthoxazine-2-thiones 34-43 and 3 aryl-2,4-dioxo-2,3-dihydro-1,3-naphthoxazines 44--51 have been prepared by reacting the corresonding naphthanilides with thiophosgene and ethyl chloroformate, respectively. All the compounds were tested for their cestodicidal activity against Hymenolepis nana infection in rats; 30 was found to be the most active compound of the series, showing 100% clearance of infection at a single oral dose of 7.5 mg/kg.