CA2100158A1 — 3-hydroxypyridin-4-one derivatives as pharmaceutical compositions

USPTO Abstract

3-Hydroxypyridin-4-ones of formula (I) in which R1 is selected from hydrogen, C1-3 aliphatic hydrocarbon groups, 2-hydroxyethyl, C1-4 aliphatic hydrocarbon groups substituted by a single carboxy, sulpho, sulphamoyl or N-methyl or N-ethyl sulphamoyl group, and an ethyl group substituted at the 1- or 2-position by a carboxy, sulpho, sulphamoyl or N-methyl or N-ethyl sulphamoyl group and at the 2-position by a hydroxy group, and R2, R3 and R4 are each separately selected from hydrogen, C1-3 aliphatic hydrocarbon groups, hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 2-methoxymethyl, C1-4 aliphatic hydrocarbon groups substituted by a single carboxy, sulpho, sulphamoyl or N-methyl or N-ethyl sulphamoyl group, and an ethyl group substituted at the 1- or 2-position by a carboxy, sulpho, sulphamoyl or N-methyl or N-ethyl sulphamoyl group and at the 2-position by a hydroxy group, but with the provisos firstly that one of R1 to R4 is a C1-4 aliphatic hydrocarbon group substituted by a single carboxy, sulpho, sulphamoyl or N-methyl or N-ethyl sulphamoyl group, or an ethyl group substituted at the 1- or 2-position by a carboxy, sulpho, sulphamoyl or N-methyl or N-ethyl sulphamoyl group and at the 2-position by a hydroxy group, secondly that either R2 or R3 is a group other than hydrogen and thirdly that the total number of atoms other than hydrogen present in R1 to R4 is no more than eight, the compound optionally being in the form of a physiologically acceptable salt and/or pro-drug thereof, are of value for the treatment of conditions caused by iron dependent parasites, particularly malaria.