1959

This invention relates to the reaction of organic substituted hydrazines with sulfur dioxide. In one specific aspect, it relates to a novel process for making organic substituted hydrazinium hydrazinesulfinates. In yet another aspect, it relates to the composition of matter produced thereby.

Syntheses of pyrazolo [3,4-d]pyrimidines with an amino group in 3- or 4-position are described. For the preparation of the 3-amino derivatives a 4-chloro-5-cyano-pyrimidine is condensed with various hydrazines. The 4-amino-pyrazolo [3,4-d]pyrimidines are obtained by reacting 3-amino-4-carbethoxy-pyrazoles with formamide, chlorinating thc 4-hydroxy-pyrazolo [3,4-d]pyrimidines, and substituting the halogen by amino groups. Some of the compounds show diuretic and cardiac activity, others inhibit tumor-growth.

The preparation of the paraxanthine, theobromine and theophylline isomers 1,5-; 2,5- and 1,7-; 2,7- and 5,7-dimethyl-4,6-dioxo-4,5,6,7-tetrahydro-pyrazolo[3,4-d]-pyrimidines is described and their structure established. A structurally specific synthesis of the caffeine and isocaffeine isomers 1,5,7- and 2,5,7-trimethyl-4,6- dioxo-4,5,6,7-tetrahydro-pyrazolo [3,4-d]pyrimidines has been realized.

This invention relates to the preparation of an adduct of iodine and polymeric 1-vinyl-2-pyrrolidone (hereinafter referred to as polyvinylpyrrolidone) whereby there is fomred a composition which is readily soluble in water to form a stable solution and which provides iodine in readily available germicidally and bactericidally active form which is essentially non-toxic to warm-blooded animals.