| abstract |
Intermediates and processes are disclosed which are useful for the preparation of a substantially pure compound of the formula: ##STR1## wherein R 6 and R 7 are each hydrogen or R 6 and R 7 are independently selected from ##STR2## wherein R a and R b are independently selected from hydrogen, loweralkyl and phenyl and R c , R d and R e are independently selected from hydrogen, loweralkyl, trifluoromethyl, alkoxy, halo and phenyl; and ##STR3## wherein the naphthyl ring is unsubstituted or substituted with one, two or three substitutents independently selected from loweralkyl, trifluoromethyl, alkoxy and halo; or n R 6 is as defined above and R 7 is R 7a OC(O)-- wherein R 7a is loweralkyl or benzyl; or n R 6 and R 7 taken together with the nitrogen atom to which they are bonded are ##STR4## wherein R f , R g , R h and R i are independently selected from hydrogen, loweralkyl, alkoxy, halogen and trifluoromethyl and R 8 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 independently selected from loweralkyl, trifluoromethyl, alkoxy and halo; or an acid addition salt thereof. |