Zaklady Farmaceutyczne Polpharma S.a.

Jerzy Drygas

Robert Rynkiewicz

Marcin Szulc

Roman Szramka

The method of synthesizing vardenafil base, in anhydrous conditions, by chlorosulfonation of 2-(2-etoxy-phenyl)-5 -methyl-7-propyl-iH-imidazo[5,1-fJ[1,2,4]triazin-4-one in a mixture of thionyl chloride and sulfurochloridic acid followed by amidation of the product, 4-etoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydroimidazo[5,1-f][1,2,4]triazin-2-yl)benzene-sulfonic acid chloride with N-ethylpiperazine, in an aprotic solvent, in the presence of an inorganic base and the method of conversion the product, vardenafil base, to yield vardenafil monohydrochloride trihydrate having a melting point of 234&#xb0; C. by contacting with water of the anhydrous modification V of vardenafil monohydrochloride in an organic solvent. The subject of the invention is also the anhydrous modification V of vardenafil monohydrochloride and its use in the preparation of vardenafil monohydrochloride trihydrate having a melting point of 234&#xb0; C.

Growing community of inventors

Krotoszyn, Poland

Jerzy Drygas