反应详情

To a mixture of (R)-3-[(1-benzyl-1H-tetrazole-5-carbonyl)-amino]-4-biphenyl-4-yl-butyric acid ethyl ester and (R)-3-[(2-benzyl-2H-tetrazole-5-carbonyl)-amino]-4-biphenyl-4-yl-butyric acid ethyl ester (180 mg, 0.383 mmol) in EtOH (1 mL) and THF (1 mL) is added aqueous 1M LiOH (2 mL). After stirring for 0.5 hour, the reaction mixture is acidified with aqueous 1M HCl. The mixture is extracted with ethyl acetate, dried over Na2SO4, and concentrated under reduced pressure. The residue is dissolved in MeOH and hydrogenated with 10% Pd/C at room temperature for 3 hours and at 40° C. for 2 hours. The reaction mixture is concentrated and purified by reverse phase HPLC to give (R)-4-biphenyl-4-yl-3-[(1H-tetrazole-5-carbonyl)-amino]-butyric acid. HPLC retention time=1.18 minutes (condition D); MS (m+1)=352; 1H NMR (400 MHz, DMSO-d6) ppm 2.56 (dd, J=5.81, 15.92 Hz, 1H), 2.67 (dd, J=7.58, 15.92 Hz, 1H), 2.85-2.99 (m, 2H), 4.55-4.64 (m, 1H), 7.26-7.35 (m, 3H), 7.43 (dd, J=7.83, 7.83 Hz, 2H), 7.56 (d, J=8.08 Hz, 2H), 7.62 (d, J=7.07 Hz, 2H), 9.28 (d, 8.84 Hz, 1H), 12.28 (s, 1H).

1. extractionThe mixture is extracted with ethyl acetate
2. dry with materialdried over Na2SO4
3. concentrationconcentrated under reduced pressure
4. dissolutionThe residue is dissolved in MeOH and hydrogenated with 10% Pd/C at room temperature for 3 hours and at 40° C. for 2 hours
5. concentrationThe reaction mixture is concentrated
6. custompurified by reverse phase HPLC