With the exclusion of moisture, 261 mg (1.00 mmol) of 3-amino-4-(3-chlorophenylamino)-1H-pyrazolo[3,4-d]pyrimidine (see Step 1.6) are dissolved in 2.5 ml of dioxane and 1 ml of DMEU; 137 I (1.1 mmol) of 3-chloro-phenyl isocyanate are added and the reaction mixture is stirred overnight at RT and finally for 16 hours at 60° C. Since, according to HPLC, not all of the pyrazolo-pyrimidine has reacted, a further 40 all of 3chloro-phenyl isocyanate are added and the mixture is stirred for a further 20 hours at 60° C. Working-up analogously to Example 66 and stirring in hot ethanol yield 4-(3-chloro-phenylamino)-3-[(3-chloro-phenyl-amino)-carbonylamino]-1H-pyrazolo[3,4-d]pyrimidine; HPLC: tRet(grad20-100)=12.4; FARMS: (M+H)+=414.
