Method for producing methyl-{ 4,6-diamino-2-1-(2-fluorobenzyl)-1h-pyrazolo3,4-bpyridino-3-ylpyrimidino-5-yl} methyl carbamate and its purification for use thereof as pharmaceutical substance

摘要

Disclosed herein is a process for preparing methyl { 4,6-diamino-2-[1-(2-fluorobenzyl)-1H -pyrazolo[3,4-b]pyridin-3-yl]pyrimidin-5-yl} methylcarbamate, the process including: cleaving 2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-5-[(E)-phenyldiazenyl]pyrimidine-4,6-diamine by catalytic hydrogenation; and , after filtration of the catalyst, precipitating 2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-4,5,6-pyrimidinetriamine from a C1-C4-alcohol and/or water without intermediate formation of salts; and utilising the 2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-4,5,6-pyrimidinetriamine so obtained in the preparation of methyl { 4,6-diamino-2-[1-(2-fluorobenzyl)-1H -pyrazolo[3,4-b]pyridin-3-yl]pyrimidin-5-yl} methylcarbamate. The process further comprises purification of the crude methyl { 4,6-diamino-2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]pyrimidin-5-yl} methylcarbamate which is dissolved in dimethyl sulphoxide and the resulting methyl { 4,6-diamino-2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]pyrimidin-5-yl} methylcarbamate sulphinyldimethane is isolated and the dimethyl sulphoxide is removed by boiling in a pharmaceutically acceptable solvent. These compounds are suitable for use in the treatment of cardiovascular disorders and erectile dysfunction.