011 known aziridine intermediates. 6 These beginnings, marked by a high level of activity, were then expanded into a series of homologs and analogs. The two routes that led to the S- 2-(w-aminoalkylamino) ethyl dihydrogen phosphorothioates 3 are outlined in Scheme I; one involved the Cortese conversion'of hydroxyethylated cqw-alkanediamines, and the other involved the Gabriel synthesis from intermediates made available by the recently developed