A mixture of 8.32 g (0.0185 mole) of the compound of Example 16, 0.9 g of 10% Pd-C catalyst, and 150 cc of tetrahydrofuran containing 20 cc of 1 M NaOH is shaken in a Paar hydrogenator under about 5.4 atm. of hydrogen pressure until hydrogenolysis is completed. The catalyst is filtered and the mother liquor is concentrated to remove the solvent. The residue is taken up with methylene chloride, and washed with water. Upon evaporating the solvent, 6.1 g of a crude product are obtained which is recrystallized from acetone yielding 4.74 g of the compound of the title. M.p. 181.5°-182.5° C.
