Original scientific paper

N 1-Substitution in 2-Methyl-4(5)-Nitroimidazole. II.

F. Kajfež ; »KRKA« Pharmaceutical and Chemical Works, Institute for Antibiotics, Pharmacy and Technology - Novo Mesta, Slovenia, Yugoslavia
D . Kolbah ; »KRKA« Pharmaceutical and Chemical Works, Institute for Antibiotics, Pharmacy and Technology - Novo Mesta, Slovenia, Yugoslavia
M . Oklobdžija ; »KRKA« Pharmaceutical and Chemical Works, Institute for Antibiotics, Pharmacy and Technology - Novo Mesta, Slovenia, Yugoslavia
T . Fajdiga ; »KRKA« Pharmaceutical and Chemical Works, Institute for Antibiotics, Pharmacy and Technology - Novo Mesta, Slovenia, Yugoslavia
M. Slamnik ; »KRKA« Pharmaceutical and Chemical Works, Institute for Antibiotics, Pharmacy and Technology - Novo Mesta, Slovenia, Yugoslavia
V . Šunjić ; »KRKA« Pharmaceutical and Chemical Works, Institute for Antibiotics, Pharmacy and Technology - Novo Mesta, Slovenia, Yugoslavia

Abstract

During the syntheses of some new derivatives of 2-methyl-4(5)nitroimidazole
with potential antitrichomonal activity, we have noticed
that the substitution on N 1 did not always depend on the pH
of the medium, as it has been stated by Pyman1- 4 and Grimison
et al.5- 8 • Therefore, we have approached the syste matic investigations
of the influence of pH on the formation of t h e 4-nitro and
5-nitroisomers of N1- s ubstituted 2-methyl-4(5)-nitroimidazole. The
results obtained indicate that the conclusion of Pyman1- 4 is valid
only when strongly alkylated agents are applied, e. g. dialkylsulphates
and alkyl tosylates9, since, with other alkylated agents
this conclusion could be applied only with restrictions· In addition,
we have measured pK:i constants for some isomer pairs prepared,
in order to apply the statem ent of Grimison et al.6 that the tautomer
ratio, calculated from pKa values, determines the ratio of the isomers
in the product mixture . In spite of the fact that the pKa
measurements were in goo d accordance with some earlier perform
e d6 ,10,15, N 1-substitution with a number of alkylating agents indicate that the statement of Grimison et al.5- 8 is of importance only for alkylation with dimethylsulphate under strictly d e termined
conditions.

Keywords

Hrčak ID:

208086

URI

https://hrcak.srce.hr/208086

Publication date:

15.10.1967.

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