| 摘要 |
A process is disclosed for the preparation of the substantially pure compound of the formula: <IMAGE> comprising catalytic hydrogenation of a compound of the formula: <IMAGE> wherein R6 and R7 are independently selected from <IMAGE> (i) wherein Ra and Rb are independently selected from hydrogen, loweralkyl and phenyl and Rc, Rd and Re are independently selected from hydrogen, loweralkyl, trifluoromethyl, alkoxy, halo and phenyl; and ubstituted or substituted with one, two or three substitutents independently selected from loweralkyl, trifluoromethyl, alkoxy and halo; or R6 and R7 taken together with the nitrogen atom to which they are bonded are <IMAGE> wherein Rf, Rg, Rh and Ri are independently selected from hydrogen, loweralkyl, alkoxy, halogen and trifluoromethyl; or an acid addition salt thereof. |
