Research I, aboratory, Kodak Limited 'l'hc, condensation of dithio-oxaniidt: with arornaticalilc~ hyt1i: s was first described hy I': phraim (I). Mow recently, Johnson and Ketcham (2) htudicd the reaction and established the structurr: of the resulting parcnt hetwocycle as thiazolo [5, 4-d 1 thiaeole (I).