D 1715 (OTTO) Diethyl ethoxymethylidenemalonate, 99% Cas 87-13-8 - used as a precursor to synthesize pyrimidinones, thiazolopyrimidines, thiazolopyrimidinones, triazolo [1, 5-a] pyrimidines, pyrimido[2,1-b]benzothiazoles and ethyl 3-amino-5-oxoisoxazolidine-4-carboxylate derivatives.