反应详情

A solution of 1,2-bis-(4-chloro-phenyl)-ethanone (100 mg, 0.38 mmol) in dichloroethane (1 mL) is stirred at room temperature while TiCL4 (143 mg, 0.75 mmol) is added in dropwise. After the addition, the mixture is stirred at room temperature for 5 min and a solution of 5-amino-1-phenyl-1H-pyrazole-4-carboxilic acid ethyl ester (97 mg, 0.42 mmol) in dichloroethane (1 mL) is added dropwise. After the addition, the mixture is heated to 125° C. for 5 h. After cooling down the mixture, it is poured into a mixture of ice cold saturated aqueous NaHCO3 solution (15 mL) and EtOAc (15 mL). The resulted mixture is filtered through celite to remove the precipitate and washed with EtOAc (2×5 mL). The filtrate is extracted by EtOAc (3×5 mL). The organic layers are combined and washed with brine and dried (MgSO4). After filtering off the drying agent, the filtrate is concentrated and purified by preparative LC/MS to provide the titled compound 5,6-bis-(4-chloro-phenyl)-1-phenyl-1H-pyrazolo[3,4-b]pyridin-4-ol as light yellow solid. (55 mg, 31%). 1H NMR (MeOD) δ(ppm) 8.37 (s, 1H), 8.23 (d, 2H), 7.53 (t, 2H), 7.34 (t, 1H), 7.31 (d, 2H), 7.29 (d, 2H), 7.23 (d, 2H), 7.15 (d, 2H); HPLC-MS calculated for C24H15C12N3O (M+1+): 432.1. Found: 432.2.

1. additionis added in dropwise
2. additionAfter the addition
3. additionAfter the addition
4. temperaturethe mixture is heated to 125° C. for 5 h
5. temperatureAfter cooling down the mixture, it
6. filtrationThe resulted mixture is filtered through celite
7. customto remove the precipitate
8. washwashed with EtOAc (2×5 mL)
9. extractionThe filtrate is extracted by EtOAc (3×5 mL)
10. washwashed with brine
11. dry with materialdried (MgSO4)
12. filtrationAfter filtering off the drying agent
13. concentrationthe filtrate is concentrated
14. custompurified by preparative LC/MS