| abstract |
The present invention relates to a process for the preparation of {4,6-diamino-2- [1- (2-fluorobenzyl) -1H-pyrazolo [3,4-b] pyridin-3-yl] pyrimidin-5- Methyl} methyl methyl carbamate of the formula (I) and a process for the purification of the crude product of the compound of formula (I) for use as a pharmaceutically active substance, being isolated for purification as intermediate or produced as intermediate in this purification process , where appropriate, in a mixture {4,6-diamino-2- [1- (2-fluorobenzyl) -1H-pyrazolo [3,4-b] pyridin-3-yl] pyrimidin-5-yl} methylcarbamate of methyl sulfinyldimethane (1: 1), that is, a compound of the formula (II). |