The new compounds 6-methyl-8-morpholino-2H pyrimido[5’,4’:5,6][1,4]thiazino[3,2e][1,2,4]triazin-3(5H)-one (3a) and 6-methyl-8-(piperidin-1-yl)-2Hpyrimido[5’,4’:5,6][1,4]thiazino[3,2-e][1,2,4]triazin-3(5H)-one (3b) were obtained from cyclocondensation of 6-bromo-1,2,4-triazine-3,5(2H,4H)-dione (1) with appropriate 5-amino-6methylpyrimidine-4-thiol (2a, b) in dimethylformamide and in the presence of potassium carbonate under reflux. Reaction of compounds (3a, b) with phosphorous oxychloride gave 4-(3-chloro-6-methyl-5H-pyrimido[5’,4’:5,6][1,4]thiazino[3,2-e][1,2,4]triazin-8-yl)morpholine (4a) and 3-chloro-6-methyl-8-(piperidin-1-yl)-5H-pyrimido[5’,4’:5,6][1,4]thiazino[3,2-e][1,2,4]triazine (4b). Nucleophilic substitution of chlorine atom of compounds (4a, b) with typical secondary amines in DMF and K₂CO₃ produced the new derivatives of the 3,8-disubstituted-5H-pyrimido[5’,4’:5,6][1,4]thiazino[3,2-e][1,2,4]triazine ring systems (5a–f). All the synthesized products were characterized and confirmed by their spectroscopic and microanalytical data.

新化合物6-甲基-8-吗啉代2 H嘧啶[5'，4'：5,6] [1,4]噻嗪基[3,2 e ] [1,2,4]三嗪-3（5 H）- （3a）和6-甲基-8-（哌啶-1-基）-2 H嘧啶基[5'，4'：5,6] [1,4]噻嗪[3,2- e ] [1 1,2,4]三嗪-3（5 ħ） -酮（3b）中从6-溴-1,2,4-三嗪-3,5-环缩合的获得（2 ħ，4 ħ） -二酮（1）与在二甲基甲酰胺中，在碳酸钾存在下，在回流下，加入合适的5-氨基-6甲基嘧啶-4-硫醇（2a，b）。化合物（3a，b）的反应用三氯氧磷得到4-（3-氯-6-甲基-5 H-嘧啶基[5'，4'：5,6] [1,4]噻嗪[3,2- e ] [1,2,4]三嗪8-基）吗啉（4a）和3-氯-6-甲基-8-（哌啶-1-基）-5 H-嘧啶基[5'，4'：5,6] [1,4]噻嗪[3，2- e ] [1,2,4]三嗪（4b）。用DMF和K ₂ CO _3中的典型仲胺对化合物（4a，b）的氯原子进行亲核取代，生成了3,8-二取代-5 H-嘧啶基的新衍生物[5'，4'：5,6] [1,4]噻嗪基[3,2- e ] [1,2,4]三嗪环系统（5a–f）。所有合成的产物均通过其光谱学和微观分析数据进行了表征和确认。