This paper presents the Synthesis of 2-R5-Oxo 5-H 6-Carbomorpholin 7-Phenyl 1;3,4-madiazolo- [3,2-a] pyrimidine through reaction of 2-R 5-Oxo 5-H 6-Ethylcarboxilate 7- phenyl 1,3,4-Thiadiazolo-[3,2-a] pyrimidine with morpholin. In particular, for the new antibacterial drugs in these homologousseries of compounds, we have syntehsized 2-R 5-Oxo 5-H 6-Carbomorpholin 7-phenyl 1, 3, 4-thiadiazolo- [3, 2-a] pyrimidine.