Hydrochloric Acid → (2S)-2-methyl-1-[(6-methyl-3-pyridinyl)carbonyl]-4-{[2-methyl-4-(trifluoromethyl)phenyl]sulfonyl}piperazine hydrochloride

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Reaction Conditions

Reaction Steps

(2S)-4-{[2-bromo-4-(trifluoromethyl)phenyl]sulfonyl}-2-methyl-1-[(6-methyl-3-pyridinyl)carbonyl]piperazine (may be prepared as described in Description 31) (216 mg, 0.427 mmol), potassium carbonate (153 mg, 1.109 mmol) in 1,4-dioxane (9 ml) were stirred for 5 min then trimethylboroxin (0.154 ml, 1.109 mmol) and Pd(PPh3)4 (84 mg, 0.073 mmol) were added and the reaction mixture heated at 100° C. for 1 h. The reaction mixture was concentrated under vacuum, dissolved in MeOH and filtered through a 5 g SCX column. LCMS showed still some triphenylphosphine oxide and another small impurity so the product was dissolved in EtOAc (40 ml) and extracted with HCl 2N (40 ml). 2 N NaOH was added to the aqueous layer until pH12 and product extracted with EtOAc (100 ml). The organic phase was dried on a phase separation cartridge and concentrated under vacuum. LCMS of the first EtOAc layer showed it contained some of the product so was extracted again with 2 N HCl (40 ml). 2 N NaOH was added to the aqueous layer until pH12 and product extracted with EtOAc (100 ml). The organic layer was dried on a phase separation cartridge and the two batches were combined and concentrated under vacuum to give the free base of the product. The product was suspended in DCM, 0.5 ml of 1 N HCl in ether was added and the solvent was evaporated to give the title compound (193 mg).

Provenance & Evidence