Method for producing salts of cyclic amidines
AssigneeDegussa-Huels Aktiengesellschaft
InventorsDieter Most, Karlheinz Drauz
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Abstract
The present invention relates to a process for the production of salts of cyclic amidines of the general formula (I) The processes described hitherto as prior art enable salts of the compound (I) to be produced only at low yields. As a result of protecting ω-amino-α-amino acids selectively at the ω-amino function, oxidative decarboxylation of the latter protected compounds by means of halogen derivatives, and subsequent cyclisation of the oxidatively decarboxylated substances with the addition of acid, according to the invention salts of the compound (I) are achieved in better yields.
Claims36
A process for the production of a salt of formula (I)
- wherein X⊖represents an inorganic anion, m=1, 2, or 3, and R represents a linear (C1-C4)-alkyl radical,which comprises:
- a) reacting an ω-amino-α-amino acid with a compound of formula (IV)
- wherein Y=C1, Br or OMe or
- and R is linear (C1-C4)-alkyl radical or an aryl radical to give a compound of formula (II)
- b) oxidizing the compound of formula (II) to give a compound of formula (III)
- c) cyclizing the compound of formula (III) in the absence of water in the presence of an acid by ring closure to give the salt compound of formula (I).
The process according to claim 11, wherein the temperature for the reaction of step (a) ranges from 5 to 25° C.
Dependencies are inferred from the claim text.