摘要 |
By reaction of a compound of the formula II <IMAGE> or a salt thereof with an agent introducing a radical of the formula -A-CO-CH3 (III> in particular by reaction of a compound of the formula II with a ketone of the formula CH2=CR-CO-CH3 (V> wherein in the above formulae the radicals R1, A and R have the meanings given in Patent Claims 1 and 4, the corresponding 7-substituted xanthine derivatives are obtained. During the reaction, the carbonyl group of the radical of the formula III or of the compound of the formula V is optionally intermediately protected. The novel compounds are useful medicaments for the treatment of disorders of the cardiovascular system, since they improve the circulation of the skeletal musculature and/or decrease or prevent arrhythmias. |