反应详情

In a solvent mixture (120 ml) of ethyl acetate and N,N-dimethylformamide (5:1) was dissolved N-carbobenzoxy-11-aminoundecanoic acid (10.1 g, 30 m mols) and p-nitrophenol (4.59 g, 33 m mols), followed by addition of N,N'-dicyclohexylcarbodiimide (6.80 g, 33 m mols). The mixture was stirred at room temperature for 15 hours, after which the precipitate was filtered off. The solvent was distilled off and the residue was crystallized in petroleum ether, recovered by filtration and recrystallized from ethyl acetate-petroleum ether. By the above procedure there was obtained 7.65 g of N-carbobenzoxy-11-aminoundecanoic acid p-nitrophenyl ester. m.p. 72°-73° C.; Rf1 =0.94.

1. filtrationafter which the precipitate was filtered off
2. distillationThe solvent was distilled off
3. customthe residue was crystallized in petroleum ether
4. filtrationrecovered by filtration
5. customrecrystallized from ethyl acetate-petroleum ether