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][C:32]([Br:35])=[CH:31][CH:30]=3)[CH2:28][CH2:27][CH2:26][CH2:25]2)[N:9]=1)=[O:7])(C)(C)C.O[Li].O>O1CCCC1>[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:30]=[CH:31][C:32]([Br:35])=[CH:33][CH:34]=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-2-[1-(4-bromophenyl)-cyclopentylmethyl]-6-hydroxypyrimidine-4-carboxylic acid tert-butyl ester (230) (7.9 g, 14.64 mmol) in tetrahydrofuran (200 mL) was added an aqueous solution (100 mL) of LiOH.H2O (6.15 g, 146.44 mmol). The resulting mixture was refluxed for 16 h. After completion of the reaction the organic solvent was removed on a rotary evaporator and water (30 mL) was added. The aqueous solution was acidified (pH 5) with concentrated HCl at 0° C. to give a white solid which was filtered off. The solid residue was triturated in diethyl ether and filtered. After drying, 5-benzyloxy-2-[1-(4-bromophenyl)-cyclopentylmethyl]-6-hydroxypyrimidine-4-carboxylic acid (231) was obtained (6.3 g, 89%) as a white solid.
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