Hydrochloric Acid → 6-[3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionylamino]-nicotinic acid

Participants

Reaction Conditions

Reaction Steps

A solution of 6-[3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionylamino]-nicotinic acid methyl ester (prepared as in Example 45, 188 mg, 0.45 mmol) in tetrahydrofuran (3 mL) was treated with a 3N aqueous hydrochloric acid solution (3 mL). The resulting reaction mixture was heated under reflux at 60° C. for 4 h. After such time, the reaction was cooled to 25° C., diluted with water (5 mL), and then extracted with ethyl acetate (3×20 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 90/10 hexanes/ethyl acetate with 1% acetic acid) afforded 6-[3-cyclopentyl-2(R)-(3,4-dichloro-phenyl)-propionylamino]-nicotinic acid (8 mg, 4%) as a white solid: [α]23589=−41.4° (c=0.099, chloroform); FAB-HRMS m/e calcd for C20H20Cl2N2O3 (M+H)+ 407.0930, found 407.0928.

Provenance & Evidence