Abstract: A process for the preparation of compounds of formula (I) in which Z is hydrogen or --NHZ is an activated amine group capable of reacting with a surface, the groups R are the same or different and each is a straight or branched C.sub.1 -C.sub.4 alkyl group, preferably methyl, n is from 2 to 6, and X is a straight or branched C.sub.1-20 alkylene group, or X is a group of formula --(CH.sub.2 CH.sub.2 O).sub.b --, or --(CH.sub.2).sub.c --Ar--(CH.sub.2).sub.d -- where b is from 1 to 20, c and d are the same or different and each is from 0 to 5, and Ar is a para- or meta- disubstituted phenyl group (preferably a para-disubstituted phenyl group) which is optionally further substituted by one or more C.sub.1 -C.sub.4 alkyl groups, or an acid addition salt thereof or a hydrate thereof, new compounds of formula (I) and salts and hydrates thereof and the use of compounds of formula (I) and salts and hydrates thereof in treating surfaces to render them more biocompatible.

Abstract: Compounds of formula (I), in which the groups R are hydrogen or C.sub.1-4 alkyl, n is from 2 to 4, X is alkylene, poly(ethoxy) or an aryl-containing group, Y is a valence bond or a divalent functional or heterocyclic group or a trivalent alkylene group, and Z is a sulphur-containing group which contains a thiol or disulphide group are useful to provide biocompatible treatments of metal surfaces, such as silver and gold surfaces. Processes for the preparation of the compounds, intermediates useful in such processes, articles having a metal surface treated with such compounds and processes of rendering metal surfaces biocompatible which comprise treating the metal surfaces with them.