6-Chloronicotinic acid → (2S)-1-[(6-Chloro-3-pyridinyl)carbonyl]-2-methyl-4-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

Participants

Reaction Steps

HATU (458 mg, 1.21 mmol) was added to a solution of 6-chloro-3-pyridinecarboxylic acid (supplied by Aldrich) (174 mg, 1.10 mmol) in DMF (4 ml) and the mixture was treated with DIPEA (0.437 ml, 2.50 mmol). This mixture was stirred for ca. 10 min at ambient temperature. (3S)-3-Methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine (may be prepared as described in Description 2) (308 mg, 1.0 mmol) was added and stirring was continued for 1.25 h. The reaction mixture was partitioned between DCM and saturated aqueous NaHCO3 solution (20 ml each). The layers were separated and the aqueous layer was washed with further DCM (2×20 ml). The combined organic layers were concentrated to leave a dark brown gum. Purification by silica chromatography (Biotage SP4, 25S cartridge), eluting with 12-100% ethyl acetate in pentane, gave the title compound (439 mg) as a pale yellow gum.

Provenance & Evidence