Medicaments, vicinal dihydroxyalkylxanthines contained therein, process for the preparation of these xanthine compounds and intermediate products suitable for these

Abstract From the Canadian patent

The invention relates to the preparation of xanthine derivatives of the formula I, (I), in which one of the radicals R1 R2 and R3 represents a, group of the formula IV (IV), or IX, (IX), R4 denoting hydrogen or methyl R6 and R7, independently of, one another being hydrogen, lower alkyl, phenyl-alkyl having up to 2 C atoms in the alkyl moiety or phenyl and n when R4 is hydrogen, denoting 2 to 6 and when R4 is methyl denoting 1 to 5, the rest of the radicals R1 R2 and R3, independently of one another denote hydrogen or alkyl, having 1 to 12 C atoms in the positions R1 and R3 and having 1 to 4 C atoms in the position R2, and the total of carbon atoms in these two radicals, being a maximum of …