4-Amino-3-(4-phenoxyphenyl)-1H-pyrazolo[3,4-d]pyrimidine (Compound 15) (4.9 g) in 200 mL dry dimethylacetamide was treated under nitrogen with 60% sodium hydride (2.0 g) and stirred 30 minutes. 1,4-dioxaspiro[4.5]dec-8-yl 4-methyl-1-benzenesulfonate (Intermediate Y) (15 g) was added and the mixture heated at 105° C. for 42 hours. Evaporation in vacuo and treating with water gave solid which was collected and washed well with water then dried in air. The solid was boiled with diethyl ether (6×120 mL) and the filtered solution evaporated. Treatment with acetone gave 1-(1,4-dioxaspiro[4.5]dec-8-yl)-3-(4-phenoxyphenyl)-1H-pyrazolo[3,4-d]pyrimidin-4-ylamine as an off-white solid which was collected and washed with acetone then dried in air m.p. 200-202.5° C. Calculated for C25H25N5O3 C 67.7 H 5.6 N 15.8 Found C 67.6H5.8 N15.4.
