New derivatives of alkaloids ergot alkaloids, their preparation and their application as medicinal products

摘要

The present invention provides compounds of formula I, IMAGE I wherein X is hydrogen, chlorine or bromine and Y is hydrogen or bromine, with the proviso that when X is chlorine Y is hydrogen, Z is carbonyl or sulphonyl, R1 is alkyl of 1 to 4 carbon atoms, and either (i) R2 is hydrogen or alkyl of 1 to 5 carbon atoms, and R3 is hydrogen, alkyl of 1 to 5 carbon atoms, or phenyl, or (ii) R2 together with R3 is a radical of formula IMAGE wherein R4, R5, R6 and R7 are, independently, hydrogen or alkyl of 1 to 4 carbon atoms, or (iii) R2 together with R4 is a radical of formula -(CH2)2-A-(CH2)2- wherein A is a bond, oxygen, sulphur or NR8 wherein R8 is hydrogen, alkyl of 1 to 4 carbon atoms, phenyl or alkoxyphenyl, useful as venotonising agents.