Synthesis of 1-Hydroxy-Substituted Pyrazolo[3,4-<i>c</i>]- and Pyrazolo[4,3-<i>c</i>]quinolines and -isoquinolines from 4- and 5-Aryl-Substituted 1-Benzyloxypyrazoles
作者:Jan Pawlas、Per Vedsø、Palle Jakobsen、Per Olaf Huusfeldt、Mikael Begtrup
DOI:10.1021/jo000986v
日期:2000.12.1
1-Hydroxypyrazolo[3,4-c]quinoline (22), 1-hydroxypyrazolo[4, 3-c]quinoline (21), 1-hydroxypyrazolo[3,4-c]isoquinoline (20), and 1-hydroxypyrazolo[4,3-c]isoquinoline (19) were prepared from 1-benzyloxypyrazole (6), establishing the pyridine B-ring in the terminal step. The pyridine ring of pyrazoloquinolines 14 and 18 was formed via cyclization of a formyl group at C-4 or C-5 and an amino group of a
1-羟基吡唑并[3,4-c]喹啉(22),1-羟基吡唑并[4、3-c]喹啉(21),1-羟基吡唑并[3,4-c]异喹啉(20)和1-羟基吡唑并[由1-苄氧基吡唑(6)制备4,3-c]异喹啉(19),在末端步骤中建立吡啶B-环。吡唑并喹啉14和18的吡啶环通过在1-苄氧基吡唑中的C-4或C-5处的甲酰基和C-5或C-4处的2-氨基苯基取代基的氨基环化而形成。吡唑并异喹啉5和9的吡啶环是通过环化在C-4或C-5处的2-甲酰基苯基取代基中的甲酰基与亚苄基吡咯烷环的C-5或C-4上安装的亚氨基磷环基团环化而形成的通过使用Staudinger / aza-Wittig方案与甲苯磺酰叠氮化物然后与三丁基膦反应。通过区域选择性金属化在C-5或C-4处引入2-氨基苯基和2-甲酰基苯基取代基,然后重金属化成吡唑基锌卤化物,随后钯催化的与2-碘苯胺或2-溴苯甲醛的交叉偶联。反应顺序和单个序列中保护基的使用已得