C([O:3][C:4]([C:6]1[C:14]2[C:9](=[N:10][CH:11]=[C:12]([C:15]3[CH:20]=[C:19]([O:21][CH3:22])[C:18]([O:23][CH3:24])=[C:17]([O:25][CH3:26])[CH:16]=3)[N:13]=2)[N:8]([CH2:27][O:28][CH2:29][CH2:30][Si:31]([CH3:34])([CH3:33])[CH3:32])[C:7]=1[CH3:35])=[O:5])C.[OH-].[Na+].Cl>C1COCC1>[CH3:35][C:7]1[N:8]([CH2:27][O:28][CH2:29][CH2:30][Si:31]([CH3:32])([CH3:34])[CH3:33])[C:9]2=[N:10][CH:11]=[C:12]([C:15]3[CH:20]=[C:19]([O:21][CH3:22])[C:18]([O:23][CH3:24])=[C:17]([O:25][CH3:26])[CH:16]=3)[N:13]=[C:14]2[C:6]=1[C:4]([OH:5])=[O:3]To a solution of 6-Methyl-2-(3,4,5-trimethoxy-phenyl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid ethyl ester (110 mg, 0.22 mmol) in 1.0 mL of THF was added a 500 uL of 5.0 M aqueous NaOH. Heated to 60° C. for 3 days. Diluted with THF, made acidic with 1.0 M HCl and partitioned into methylene chloride. Dried the organic phase over Na2SO4, filtered, and concentrated. Collect 107 mg of 6-Methyl-2-(3,4,5-trimethoxy-phenyl)-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid sufficiently pure for the next step.
Wird geladen…