反应详情

1,3-Cyclopentane dicarboxylic acid (8.0 g., 51 mmole) was converted to the anhydride by refluxing for 3 hours in 100 ml. of acetic anhydride. The excess solvent was removed under vacuum and the residue was stored in vacuum for 18 hours. The crude anhydride thus obtained was combined with 14 g. (50 mmole) of 1-(4-aminobutyl)-4-benzylpiperazine hydrochloride and 5.0 g. (50 mmole) of triethylamine in 500 ml. of xylene. The mixture was refluxed for 48 hours with water separation via a Dean-Stark trap. The product was concentrated under vacuum and chromatographed on 200 g. of silica gel with 2% ethanol/chloroform. The product was crystallized from ethanol by addition of 4N HCl/isopropyl alcohol to obtain cyclopentane-1,3-dicarboxylic-N-[4-(4-benzyl-1-piperazinyl)butyl]imide dihydrochloride; m.p. 273°-275° C.

1. temperatureby refluxing for 3 hours in 100 ml
2. customThe excess solvent was removed under vacuum
3. customThe crude anhydride thus obtained
4. concentrationThe product was concentrated under vacuum
5. customchromatographed on 200 g
6. customThe product was crystallized from ethanol by addition of 4N HCl/isopropyl alcohol