反应详情

温度

80 °C

In order to remove residual water, some solvent is distilled off from a suspension of 75.8 g (216 mmol) of 3-benzylamino-4-(3-chloro-phenylamino)-1H-pyrazolo[3,4-d]-pyrimidine in 1.5 liters of benzene. Then, with exclusion of moisture, the suspension is introduced into 84 g of aluminum chloride (Fluka, Buchs/Switzerland) in 500 ml of benzene. The reaction mixture is heated at 80° C. for 2.5 hours and then cooled to RT. The supernatant benzene phase is poured into 2 kg of ice-water (leaving behind a green, oily residue) and the solid that precipitates is filtered with suction and rinsed thoroughly with water (→K1). Using a rotary evaporator, the benzene is evaporated off from the filtrate, and the aqueous phase that remains is added, together with 1 kg of ice, to the green, oily residue and hydrolysis is carried out for 2 hours at 40° C. The crystalline product is filtered with suction and rinsed with water (→K2). K1 and K2 are taken up in 1 liter of methanol, acidified with 4N aqueous HCl and partially concentrated by evaporation. Water is added and the methanol is evaporated off completely. The crystals are filtered off and rinsed with water. The same purification procedure is repeated with semi-saturated Na2CO3 solution/methanol and water/methanol. Stirring at 50° C. in methanol, precipitation with diethyl ether, filtering and drying yield 3-amino-4-(3-chloro-phenylamino)-1H-pyrazolo[3,4-d]pyrimidine; m.p. 232-234° C.; TLC: Rf =0.50 (ethyl acetate).

1. customIn order to remove residual water
2. temperaturecooled to RT
3. customleaving behind a green, oily residue) and the solid
4. customthat precipitates
5. filtrationis filtered with suction
6. washrinsed thoroughly with water (→K1)
7. customa rotary evaporator
8. customthe benzene is evaporated off from the filtrate
9. additionthe aqueous phase that remains is added, together with 1 kg of ice
10. customto the green, oily residue and hydrolysis
11. filtrationThe crystalline product is filtered with suction
12. washrinsed with water (→K2)
13. concentrationpartially concentrated by evaporation
14. additionWater is added
15. customthe methanol is evaporated off completely
16. filtrationThe crystals are filtered off
17. washrinsed with water
18. customThe same purification procedure
19. customprecipitation with diethyl ether
20. filtrationfiltering
21. customdrying