C([O:5][C:6]([C:8]1[C:13]([O:14][CH2:15][C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)=[C:12]([OH:22])[N:11]=[C:10]([CH2:23][C:24]2([C:29]3[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=3)[CH2:28][CH2:27][CH2:26][CH2:25]2)[N:9]=1)=[O:7])(C)(C)C>O1CCCC1.O>[CH2:15]([O:14][C:13]1[C:8]([C:6]([OH:7])=[O:5])=[N:9][C:10]([CH2:23][C:24]2([C:29]3[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=3)[CH2:25][CH2:26][CH2:27][CH2:28]2)=[N:11][C:12]=1[OH:22])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1To a stirred solution of 5-benzyloxy-6-hydroxy-2-(1-phenyl-cyclopentylmethyl)-pyrimidine-4-carboxylic acid tert-butyl ester (282) (1.6 g. 3.48 mmol) in a mixture of tetrahydrofuran:water (2:1) (90 mL), was added lithium-hydroxide monohydrate (2.9 g, 69.57 mmol) and the reaction mixture was refluxed for 18 h. After completion of the reaction, all volatiles were evaporated, added water (30 mL) and washed with ethyl acetate (2×20 mL) to remove non acidic impurities. The separated aqueous part was acidified with 1N HCl to reach a pH of about 5 to 6. The acidified aqueous part was extracted with ethyl acetate (4×50 mL), dried and concentrated to get 5-benzyloxy-6-hydroxy-2-(1-phenyl-cyclopentylmethyl)-pyrimidine-4-carboxylic acid (283) (780 mg, 55.44%) as a white solid.
Loading…