[C:1]([C:5]1[CH:6]=[C:7]([C:16]2[C:24]3[C:19](=[N:20][CH:21]=[CH:22][CH:23]=3)[NH:18][N:17]=2)[CH:8]=[C:9]([C:12]([CH3:15])([CH3:14])[CH3:13])[C:10]=1[OH:11])([CH3:4])([CH3:3])[CH3:2].C(=O)([O-])[O-].[K+].[K+].[C:31]([O:34][CH2:35][CH2:36]Br)(=[O:33])[CH3:32]>CN(C)C=O>[C:31]([O:34][CH2:35][CH2:36][N:18]1[C:19]2=[N:20][CH:21]=[CH:22][CH:23]=[C:24]2[C:16]([C:7]2[CH:8]=[C:9]([C:12]([CH3:15])([CH3:14])[CH3:13])[C:10]([OH:11])=[C:5]([C:1]([CH3:2])([CH3:3])[CH3:4])[CH:6]=2)=[N:17]1)(=[O:33])[CH3:32]To a solution of 40 g of 3-(3,5-di-tertiary butyl-4-hydroxyphenyl)-1H-pyrazolo[3,4-b]pyridine in 300 ml of dimethylformamide are added 34,2 g of potassium carbonate and 31 g of 2-acetoxyethyl bromide, and the mixture is stirred at 60° C. for 11 hours. The resulting mixture is poured into ice-cold water and the precipitate is extracted with ethyl acetate and then the extract is washed with water, dried and concentrated. The resulting residue is recrystallized from isopropyl alcohol to give 43 g of 1-(2-acetoxyethyl)-3-(3,5-di-tertiary butyl-4-hydroxyphenyl)-1H-pyrazolo[3,4-b]pyridine as white crystals, melting at 115°-116° C.
Loading…