In previous the reactions of ureas with N-alkyl-and N-arylthioureas to give excellent ethoxymethylene derivatives of diethyl malonate, yields of 5-carbethoxy-2-thiouracils (11). Equally ethyl cyanoacetate and ethyl oxalacetate were good yields of 5-carbethoxy-2- thiocytosines (I11 j shown to yield carbethoxypyrimidines. In this and 5-cyano-2- thiocytosines (V) were obtained from present work, ethoxymethylene derivatives of this the ...
