Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... A rapid and efficient synthesis of imidazo [1,2-a] and 1,2,4-triazolo [4,3-a]-piperazine car☐ylic acids. ... Department of Chemistry, Recherche Synthex France, Leuville-sur-Orge, 91310 Montlhe'ry, France. ... A simple and general synthesis of novel cyclic α-amino acids by a ...