Process of making penicillamine
AssigneeDeutsche Gold- und Silber-Scheideanstalt vormals Roessler
InventorsFriedrich Asinger, Wolf-Dieter Pfeifer, Heribert Offermanns, Paul Scherberich, Gerd Schreyer
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Abstract
Penicillamine or a homolog thereof is obtained by reacting a 2-disubstituted-5,5-alkyl-thiazolidine nitrile, alkyl having 1 to 6 carbon atoms, with a mineral acid in a two-stage proceeding wherein in the first stage relatively low temperatures and a relatively high concentration of the mineral acid are employed while in the second stage the concentration of the acid is relatively low and the temperatures are relatively high, the term "relatively" referring to the relationship of said two stages of the reaction with mineral acid.
Claims7
A process for the production of a compound having the formula ##STR3## wherein:
- R.sub.3 and R.sub.4 are each alkyl of 1 to 6 carbon atoms or which together form a closed ring,
- which process comprises heating in two stages in the presence of at least a stoichiometric amount of water and hydrochloric acid a thiazolidine-4-carbonitrile having the formula:
- ##STR4## wherein:
- R.sub.3 and R.sub.4 have the meaning as above, and
- R.sub.1 and R.sub.2 are each alkyl of 1 to 6 carbon atoms
- or which together form a closed ring, or are alkenyl of 2-4 carbon atoms or alkyl-substituted aryl, the alkyl substituent having a total of 1-2 carbon atoms,
- the heating in the first stage being conducted at a temperature between 20.degree. and 80.degree. C in hydrochloric acid having a concentration of at least 30% by weight of hydrogen chloride, and the heating in the second stage being conducted at a temperature between 80.degree. and 110.degree. C in hydrochloric acid having a concentration of at least 10 and at most 30% by weight of hydrogen chloride and extracting the compound above I or its hydrochloride from the mixture.
Dependencies are inferred from the claim text.