compounds of the present invention may be prepared from a heterocyclic aldehyde of the formula str3 the heterocyclic aldehyde i is first converted to an amino acid by known methods for example by the well known strecker amino acid synthesis ann 75 27 1850 91 349 1854 this method involves the synthesis of u03b1 amino acids by the simultaneous reaction of aldehydes with ammonia and hydrogen cyanide followed by hydrolysis of the resulting amino nitriles as applied to the heterocyclic aldehyde i of the present invention the reaction is as follows str4 in addition various well known modifications of the strecker synthesis may be employed for example the erlenmeyer modification str5 the amino acid of the formula str9 produced by any suitable method for example those described above is then reacted with an alkali metal cyanate or an alkaline earth metal cyanate to form an u03b1 ureido compound of the formula str10 this reaction takes place by treating an aqueous suspension of the u03b1 amino acid with the alkali or alkaline earth metal cyanate acidification with hydrochloric acid precipitates the u03b1 ureido acid in good yield a solution of the u03b1 ureido acid in an organic solvent containing a tri lower alkyl amine is converted to a mixed carbonic or other anhydride iv by treating with an anhydride forming reagent e g a lower alkyl.