7-(2-((2-(3,4-Dihydroxyphenyl)-2-hydroxyethyl)amino)ethyl)-3,7-dihydro-1,3-dimethyl-1H-purine-2,6-dione

Preparationsolution of 27 g of ω-chloroacetylcatechol in 150 ml of ethanol was added dropwise over 2 hours to a stirred reflux solution of 81 g of 7-(β-aminoethyl)theophylline in 200 ml of 60% ethanol. The mixture was then boiled for 3.5 hours under nitrogen purging. The precipitate was separated by filtration, washed with water, and dried. The product was suspended in alcohol and mixed with hydrochloric acid while heating until an acid reaction was observed. After cooling, the mixture was filtered. In this manner, 37 g of 7-[β-(β'-3,4-dihydroxyphenyl-β'-oxoethylamino)ethyl]theophylline hydrochloride with a melting point of 246-249 °C was obtained. To obtain an analytically pure product, the hydrochloride was dissolved in water and precipitated with acetone. 7.1 g of 7-[β-(β'-3,4-dihydroxyphenyl-β'-oxoethylamino)ethyl]theophylline hydrochloride was dissolved in 500 ml of distilled water and hydrogenated at 48°C in the presence of 1 g of platinum oxide. When no further hydrogen absorption occurred after approximately 5 hours, the mixture was evaporated to dryness under vacuum. Purification was performed by absorbing methanol and mixing with ethyl acetate. The Theodrenaline hydrochloride crystals obtained after several days were separated by suction filtration and dried in a desiccator to give 6.1 g.