1,1'-Carbonyldiimidazole → NGB 2904 hydrochloride

Participants

Reaction Steps

A mixture of 9H-fluorene-2-carboxylic acid (100 mg, 0.48 mmol) and 1.1'-carbonyldiimidazole (80 mg, 0.5 mmol) in 10 mL of anhydrous tetrahydrofuran was stirred for 8 hours. A solution of 4-[4-(2,3-dichlorophenyl)-1-piperazinyl]-1-aminobutane (150 mg, 0.5 mmol) in 1 mL of tetrahydrofuran was added and the resulting mixture was stirred for 30 minutes. The reaction mixture was partitioned between ethyl acetate and water. The organic layer was washed with aqueous Na2CO3 solution, dried (Na2SO4) and concentrated in vacuo to give the title compound (185 mg, 78%). Hydrochloride salt was prepared by treating the free base with a solution of hydrogen chloride in ethyl acetate (mp 262-4° C.).

Provenance & Evidence