PROCESS FOR THE PREPARATION OF A SUBSTITUTED 2,5-DIAMINO-3-HYDROXYHEXANE

Intermediates and processes are disclosed which are useful for the preparati on of a substantially pure compound of formula (3), wherein R6 and R7 are each hydrogen or R6 and R7 are independently selected from (i), wherein Ra and Rb are independently selected from hydrogen, loweralkyl and phenyl and Rc, Rd a nd Re are independently selected from hydrogen, loweralkyl, trifluoromethyl, alkoxy, halo and phenyl; and (ii) wherein the naphthyl ring is unsubstituted or substituted with one, two or three substituents independently selected fr om loweralkyl, trifluoromethyl, alkoxy and halo; or R6 is as defined above and R7 is R7aOC (O)-wherein R7a is loweralkyl or benzyl; or R6 and R7 taken togethe r with the nitrogen atom to which they are bonded are (a) or (b), wherein Rf, Rg, Rh and Ri are independently selected from hydrogen, loweralkyl, alkoxy, halogen and trifluoromethyl and R8 is hydrogen or -C(O)R" wherein R" is loweralkyl, alkoxy, benzyloxy or phenyl wherein the phenyl ring is unsubstituted or substituted with one, two or three substituents independent ly selected from loweralkyl, trifluoromethyl, alkoxy and halo; or an acid addition salt thereof.