Abstract: 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° 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° C.

Abstract: 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° 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° C.

Abstract: A process for the preparation of [1-hydroxy-2-(1H-imidazol-1-yl)-ethylidene]bisphosphonic acid consists of the reaction of aqueous solution of 1H-imidazole-1-acetic acid hydrochloride with phosphorus trichloride followed by removal of the excess of phosphorus trichloride, addition of water and hydrolysis of the reaction products. In order to isolate the product the post-reaction mixture is filtered and the anti-solvent is added to the aqueous filtrate in order to crystallize out [1-hydroxy-2-(1H-imidazol-1-yl)-ethylidene]bisphosphonic acid monohydrate.

Abstract: The invention relates to a novel process for the preparation of [1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid and hemipentahydrate monosodium salt thereof comprising (a) reacting an aqueous solution of 3-pyridyl acetic acid hydrochloride with phosphorus trichloride; (b) removing unreacted phosphorus trichloride; (c) adding water and hydrolyzing; (d) isolating crystalline [1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid; (e) suspending said crystalline [1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid in water; (f) adding sodium hydroxide, filtering off, and washing; and (g) drying obtained hemipentahydrate monosodium salt of 1-hydroxy-2-(3-pyridinyl)ethylidene]bisphosphonic acid.

Abstract: A process for the preparation of [1-hydroxy-2-(1H-imidazol-1-yl)-ethylidene]bisphosphonic acid consists of the reaction of aqueous solution of 1H-imidazole-1-acetic acid hydrochloride with phosphorus trichloride followed by removal of the excess of phosphorus trichloride, addition of water and hydrolysis of the reaction products. In order to isolate the product the post-reaction mixture is filtered and the anti-solvent is added to the aqueous filtrate in order to crystallize out [1-hydroxy-2-(1H-imidazol-1-yl)-ethylidene]bisphosphonic acid monohydrate.

Abstract: A novel process for the preparation of a sodium salt of 1-(((1(R)-(3-(2-(7-chloro-2-quinolinyl)-ethenyl)phenyl)-3-(2-(1-hydroxy-1-methyl-ethyl)phenyl)propyl)sulfanyl)methyl)cyclopropaneacetic acid, comprising: a) reacting a compound of Formula 1 with methanesulfonyl chloride in the presence of a tertiary amine to yield a crude solution of a compound of Formula 2; b) filtering the crude solution of compound of Formula 2 obtained in a) to remove solid amine hydrochloride, reacting the filtrate without isolation or further purification with a compound of Formula 3, and isolating 1-(((1(R)-(3-(2-(7-chloro-2-quinolinyl)-ethenyl)phenyl)-3-(2-(1-hydroxy-1-methylethyl)phenyl)propyl)sulfanyl)methyl)cyclopropaneacetic acid; c) reacting the 1-(((1(R)-(3-(2-(7-chloro-2-quinolinyl)-ethenyl)phenyl)-3-(2-(1-hydroxy-1-methylethyl)phenyl)propyl)sulfanyl)methyl)cyclopropaneacetic acid isolated in b) with tert-butylamine to yield a compound of formula 4; d) isolating and purifying the compound of formula 4; and e) converting th

Abstract: The invention relates to a novel process for the preparation of [1-hydroxy-2-(3-pyridinyl)ethylidene] bisphosphonic acid and hemipentahydrate monosodium salt thereof comprising (a) reacting an aqueous solution of 3-pyridyl acetic acid hydrochloride with phosphorus trichloride; (b) removing unreacted phosphorus trichloride; (c) adding water and hydrolyzing; (d) isolating crystalline [1-hydroxy-2-(3-pyridinyl)ethylidene] bisphosphonic acid; (e) suspending said crystalline [1-hydroxy-2-(3-pyridinyl)ethylidene] bisphosphonic acid in water; (f) adding sodium hydroxide, filtering off, and washing; and (g) drying obtained hemipentahydrate monosodium salt of 1-hydroxy-2-(3-pyridinyl)ethylidene] bisphosphonic acid.

Abstract: A method and apparatus for reducing electromagnetic emissions from switching-type battery chargers safely and at low cost. The method and apparatus generally comprises enclosing the battery charger in a conductive metal case, electrically and physically isolating the low voltage, high current output components from the remainder of the circuitry, reducing the loop area of the output circuit, use of ferrite beads on various conductors, use of an output common-mode inductor wound within a ferrite core, use of inductors and transformers having foil windings, and use of a fusible resistor to protect internal circuitry. The battery charger includes a secondary assembly printed circuit board and a primary assembly printed circuit board which are supported in a spaced apart, substantially parallel arrangement.

Abstract: A method and apparatus for reducing electromagnetic emissions from switching-type battery chargers safely and at low cost. The method and apparatus generally consists of enclosing the battery charger in a conductive metal case, electrically and physically isolating the low voltage, high current output components from the remainder of the circuitry, reducing the loop area of the output circuit, use of ferrite beads on various conductors, use of an output common-mode inductor wound within a ferrite core, use of inductors and transformers having foil windings, and use of a fusible resistor to protect internal circuitry.