(2S)-1-[(6-Chloro-2-methyl-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine (may be prepared as described in Example 24) (67 mg, 0.15 mmol) was weighed into a microwave vial, and dissolved in isopropanol (0.7 ml). Ethylamine, 2.0M in methanol (1.5 ml, 3.0 mmol) was added, and the clear solution was heated in the microwave to 120° C. for 6 h with stirring. LCMS analysis showed <20% conversion. The mixture was treated with further ethylamine, 2.0M in methanol (0.75 ml, 1.50 mmol) and returned to the microwave for 18 h at 120° C. with stirring. LCMS analysis showed ˜50% conversion. The reaction mixture was treated with further ethylamine, 2.0M in methanol (1.5 ml, 3.0 mmol), and again heated in the microwave for 18 h at 120° C. with stirring. LCMS now showed adequate conversion, >65%. The reaction mixture was concentrated to give the crude material as a yellow gum (76 mg). This was purified by MDAP to give the free base of the title compound as a pale yellow gum (34 mg).
