Process for preparing methyl {4,6-diamino-2-[5-fluoro-1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]pyrimidin-5-yl}carbamate

The present application relates to a novel and efficient process with high yield for preparing methyl {4,6- diamino-2-[5-fluoro-1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]pyrimidin-5-yl}carbamate of the formula (I) in the crystalline form of modification I, wherein the x-ray diffractogram of the compound of the formula (I) in modification I exhibits peak maxima of the 2 theta angle at 5.9, 6.9, 22.7, in very high purity which is significantly more cost-effective than the process known from the art and can be performed in customary pilot- and production plant-equipment (stirred tank/devices for isolation).