[CH2:1]([O:8][C:9]1[C:10]([C:29]([OH:31])=O)=[N:11][C:12]([CH2:16][C:17]2([C:22]3[CH:27]=[CH:26][C:25]([Br:28])=[CH:24][CH:23]=3)[CH2:21][CH2:20][CH2:19][CH2:18]2)=[N:13][C:14]=1[OH:15])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[Si:32]([O:39][CH2:40][CH2:41][NH:42][CH:43]([CH3:45])[CH3:44])([C:35]([CH3:38])([CH3:37])[CH3:36])([CH3:34])[CH3:33].O=P(Cl)(Cl)Cl>N1C=CC=CC=1>[Si:32]([O:39][CH2:40][CH2:41][N:42]([CH:43]([CH3:45])[CH3:44])[C:29]([C:10]1[C:9]([O:8][CH2:1][C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=2)=[C:14]([OH:15])[N:13]=[C:12]([CH2:16][C:17]2([C:22]3[CH:23]=[CH:24][C:25]([Br:28])=[CH:26][CH:27]=3)[CH2:21][CH2:20][CH2:19][CH2:18]2)[N:11]=1)=[O:31])([C:35]([CH3:38])([CH3:37])[CH3:36])([CH3:34])[CH3:33]To a stirred solution of 5-benzyloxy-2-[1-(4-bromophenyl)-cyclopentylmethyl]-6-hydroxypyrimidine-4-carboxylic acid (231) (2.0 g, 4.14 mmol) and [2-(tert-butyl-dimethylsilanyloxy)-ethyl]-isopropyl-amine (8b) (2.7 g, 12.41 mmol) in pyridine (25 ml), was added POCl3 (1.16 ml, 12.41 ml) at −10° C. The reaction mixture was stirred at this temperature for 5 h. After completion of the reaction, the reaction mixture was quenched with water and the mixture was extracted with ethyl acetate. The organic part was washed with water, separated and dried over Na2SO4. After evaporation, the crude product was purified by 100-200 silica gel column chromatography using 30% ethyl acetate in hexane as the eluent to give 5-benzyloxy-2-[1-(4-bromophenyl)-cyclopentylmethyl]-6-hydroxypyrimidine-4-carboxylic acid [2-(tert-butyl-dimethylsilanyloxy)-ethyl]-isopropylamide (232) (0.9 g, 32%) as a brown solid.
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