Monopyrrolische VorHiufer fur die Synthese des Uroporp hyrinogen -octani trils

Sa？etak Syntheses of the pre-uroporphinoid monopyrrolic derivatives porphobilinogen dinitrile, deaminomethyl-porphobilinogen dinitrile and 5-deaminomethyl-2-hydroxymethyl-porphobilinogen dinitrile make multiple use of the crystalline Mannich salt dimethyl- -methylidene-iminiumjodide as areagent for the introduction of cyanomethyl and ,B-cyanoethylside chains at the ,B-positionof the pyrrol nucleus. The paper is the first in a series of reports on the chemistry of uroporphyrinogen octanitrile