The preparation of the caffeine isomers 1,5,7- and 2,5,7-trimethyl-4, 6-dioxo-4,5,6,7-tetrahydro-pyrazolo[3,4-d]pyrimidines is described and their structures established. The compounds exhibit diuretic and cardiac activity.
This invention relates to a process of stabilizing a dry powered adduct of iodine and polymeric 1-vinyl-2-pyrrolidone (hereinafter referred to as polyvinyl pyrrolidone) whereby a stable composition is obtained which when dissolved in water will not change its pH and maintain a constant available iodine content.
