399 
However the comparison of the oxidation produet of haemopyrro- 
line with the syntheticaily prepared imide showed that they are 
not identical — their melting points differ not inconsiderably (the 
difference amounts to 7°C). The authors named were not able 
however to analyze the acid obtained from haemopyrroline and the 
results, it may be hoped, are not absolutely binding. 
In view of the great probability of the haemopyrroline formula 
as given above, and having started synthetical experiments with 
the view to prepare artificially haemopyrroline at the same time 
as Küster, and in any case independently from this author, we 
have decide to test the said formula by a method differing from 
the one followed up by Küster. Our idea was to reduce the imide 
of methyl-n- propyl-maleie acid and compare the product obtained 
with haemopyrroline, formed by haemin. 
The preparation of methyl-n-propyl-maleie anhydride does 
not offer any diffieulties: propylacetoacetie ether is eondensed with 
prussie acid. the product obtained saponified and the methyl-propyl 
malie acid produced distilled The reaction takes place smoothly, 
exactly in accordance with other similar synthesis described by 
Michael and Tissot. The properties of the anhydride agree in 
general with the descyiption given by Küster and Haas and 
we may pass over at present any details. The imide we obtained by 
prolonged heating of the anhydride with alcoholie ammonia to 110°. 
Whereas Küster and Haas describe crystalls of this substance 
we never were so fortunate as to get it in the crystalline state. 
The imide we tried to convert into haemopyrroline in exactly the 
same ‘manner as Bell converted suceinie imide into pyrroline, 
viz. we heated it with a large excess of zinc dust in the pre- 
sence of hydrogen. There distilled very soon a thick liquid which 
possessed a smell similar to that of haemopyrroline, and which on 
being treated with diluted hydrochlorie acid dissolved partly, leaving 
a brown, greasy substance behind. The solution in dilute hydro- 
ehlorie acid gave, on being left over night in the presence of air, 
a reddish brown precipitate, which dissolved easily in alcohol with 
a brownish red eolour; this solution showed an absorption speetrum 
similar to that of urobilin and gave with ammoniacal zine chloride 
a fluorescent (greenish) liquor, showing a spectrum similar to that 
of zine urobilin. In other words, the reduction product of methyl- 
n-propyl-maleie imide yields under the influence of oxygen of the 
1* 
