A mixture of 4.6 g of benzylic acid, 3.2 g of 1,1'-carbonyldiimidazole, and 150 ml of DMF were mixed and stirred for 1 hour. A solution of 5.0 g of 4-amino-α-hexyl-1H-imidazole-1-acetic acid ethyl ester in DMF was added and the mixture stirred at room temperature overnight. The reaction mixture was concentrated in vacuo, ethyl acetate was added, and the organic solution was washed sequentially with water, a 10% sodium hydroxide solution, and water. The organic layer was dried over sodium sulfate and concentrated in vacuo. The residue was purified by HPLC eluting with 30% ethyl acetate in toluene. The appropriate fractions were combined and concentrated in vacuo to provide 1.4 g of the desired titled product.
