Hydroxyphenylacetic acid → 4-(3-Adamantan-1-yl-ureido)butyric Acid 4-Ethoxycarbonylmethylphenyl Ester

Participants

Reaction Steps

To a solution of 4-(3-adamantan-1-yl-ureido)butyric acid 822 (0.15 g, 0.54 mmol), DMAP (0.07 g, 0.54 mmol), and 4-hydroxyphenylacetic acid (0.09 g, 0.59 mmol) in methylene chloride (20 mL) was added EDCI (0.11 g, 0.59 mmol) at room temperature. After stirring for 12 h, the reaction mixture was washed with water (20 mL), and the methylene chloride solution dissolving the product was dried over Na2SO4 and concentrated to give conjugated product. This crude mixture in DMF (30 mL) was treated with bromoethane (0.15 g, 1.34 mmol) and K2CO3 (0.18 g, 1.34 mmol) at room temperature and stirred for 12 h at room temperature. The ethyl ester product was extracted with ether (30 mL), and the ether solution was washed with 1 N NaOH aqueous solution (20 mL) and water (30 mL), dried over Na2SO4, and concentrated. The residue was purified by column chromatography on silica gel eluting hexane and ethyl acetate (5:1) to give 852 (47 mg, 20%) as a white solid: 1H NMR (CDCl3) 1.40 (3H, t, J=6.9 Hz), 1.66-1.68 (6H, m), 1.89-1.95 (8H, m), 2.05-2.07 (3H, m), 2.62 (2H, t, J=6.9 Hz), 3.25 (2H, q, J=6.9 Hz), 3.60 (2H, s), 4.07 (1H, s), 4.16 (2H, q, J=6.9 Hz), 4.29 (1H, s), 7.08-7.10 (2H, m), 7.28-7.30 (2H, m); LC-MS (ESI) m/z calcd for C25H34N2O5 [M+H]+ 443.25. found [M+H]+ 443.25; mp 95-97 C. Anal. (C25H34N2O5) C, H, N.

Provenance & Evidence