GB862127A - Derivatives of 2-hydroxy-3-naphthanilide - Google Patents

Abstract

The invention comprises compounds of the formula <FORM:0862127/IV (b)/1> (wherein R1 is hydrogen, an alkyl radical of at most 16 carbon atoms or a dialkylamino or aralkyl radical, R2 has the same values excluding hydrogen, or R1 and R2 are joined to form, together with the nitrogen atom, a saturated heterocyclic ring which may be alkyl substituted and wherein the benzene ring A bears at least one substituent selected from halogen atoms and alkyl of at most 6 carbon atoms, alkoxy of at most 6 carbon atoms, acyl, alkylaminosulphonyl, carboxy, benzamido, phenoxy and tolyloxy radicals provided that when this ring has a 2-methyl or 2-methoxy substituent at least one additional substituent is also present therein) and acid-addition salts thereof; and their preparation by reacting the corresponding 1 - unsubstituted - 2 - hydroxy - 3 - naphthanilide with formaldehyde or a functional derivative thereof and the amine R1R2NH. Suitably paraformaldehyde is used and the reaction is effected in a solvent such as aqueous ethanol or benzene. It may be accelerated or completed by the application of heat, by addition of excess amine or by the addition of a tertiary amine. Examples are given and hydrochlorides of some of the products are described. The Provisional Specification describes compounds of the formula <FORM:0862127/IV (b)/2> (wherein R and R1 are hydrogen or hydrocarbon radicals, optionally substituted, or form, together with the nitrogen atom, a heterocyclic ring, and the benzene ring A may optionally bear one or more substituents) other than the compounds disclosed in U.S.A. Specification 2,234,036.