反应详情

A mixture of 2,4-difluoro-4′-(3-nitro-benzyloxy)-biphenyl (26.3 mg, 0.077 mmol) and 10% Pd/C (5.3 mg) in EtOH (3 mL) containing 2 drops 2N HCl was hydrogenated at 50 psi for 2 hrs. The reaction mixture was filtered and evaporated. The crude product was dissolved in DMF (1 mL) with rac-(trans)-cyclopentane-1,2-dicarboxylic acid monobenzyl ester (19.5 mg, 0.77 mmol), triethylamine (32 uL, 0.231 mmol) and BOP (33 mg, 0.077 mmol). The mixture was stirred for 1 hr at RT. DMAP (1 mg) was added and stirring continued overnight. The reaction mixture was diluted with EtOAc (20 mL), washed with 2.5% KHSO4 (3×10 mL), 50% saturated NaHCO3 (10 mL), saturated NaCl (10 mL), dried over MgSO4, filtered and evaporated. The crude ester was purified by flash chromatography with a 0-20% gradient of ethyl acetate in hexanes to yield 18.3 mg of (trans)-2-[3-(2′,4′-difluoro-biphenyl-4-yloxymethyl)-phenylcarbamoyl]-cyclopentanecarboxylic acid benzyl ester as a clear oil. This material was dissolved in EtOH (3 mL) with 10% Pd/C (4 mg) and hydrogenated at 50 psi for 1 hr. The reaction mixture was filtered through Celite and evaporated to give (trans)-2-[3-(2′,4′-difluoro-biphenyl-4-yloxymethyl)-phenylcarbamoyl]-cyclopentanecarboxylic acid as a white solid (16.4 mg, 47%). LC-MS (ES) calculated for C26H23F2NO4, 451.47; found m/z 450.2 [M−H]−.

1. filtrationThe reaction mixture was filtered
2. customevaporated
3. stirringstirring continued overnight
4. washwashed with 2.5% KHSO4 (3×10 mL), 50% saturated NaHCO3 (10 mL), saturated NaCl (10 mL)
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. customevaporated
8. customThe crude ester was purified by flash chromatography with a 0-20% gradient of ethyl acetate in hexanes