Abstract Benzil was reacted with cyanoacetohydrazide under microwave irradiation to give 3-oxo-5,6-diphenyl-2,3-dihydropyridazine-4-carbonitrile 1 which used as starting material for the synthesis of new heterocyclic compounds. Chlorination of pyridazinone 1 with POCl3 afforded the chloro-pyridazine derivative 3, which then condensed with 2-aminothiazole or hydrazine hydrate to produce 3,4-diphenyl-5H-thiazolo[3′,2′:1,2]pyrimido[4,5-c]pyridazin-5-one 5 or 3-hydrazinyl-5,6-diphenylpyridazine-4-carbonitrile 6, respectively. New Schiff bases were obtained by condensation reactions of compound 6 with different aldehydes. On the other hand, compound 6 reacted with different carbon electrophiles naming acetyl acetone, diethyl malonate, and phenyl isothiocyanate producing new pyarazolo-pyridazine derivatives 11, 12, and 14, respectively. Chemical structures of all newly synthesized compounds were confirmed on the basis of spectral data and had been screened for antimicrobial and antioxidant activity. GRAPHICAL ABSTRACT

中文翻译：

---

新型环状哒嗪衍生物的合成及其抗氧化和抗菌活性研究

摘要 苄基与氰基乙酰肼在微波辐射下反应，得到3-oxo-5,6-diphenyl-2,3-dihydropyridazine-4-carbonitrile 1，可作为合成新杂环化合物的原料。用 POCl3 氯化哒嗪酮 1 得到氯哒嗪衍生物 3，然后与 2-氨基噻唑或水合肼缩合生成 3,4-二苯基-5H-噻唑并[3',2':1,2]嘧啶[4， 5-c]pyridazin-5-one 5 或 3-hydrazinyl-5,6-diphenylpyridazine-4-carbonitrile 6。通过化合物6与不同醛的缩合反应得到新的席夫碱。另一方面，化合物 6 与命名为乙酰丙酮、丙二酸二乙酯和异硫氰酸苯酯的不同碳亲电子试剂反应，分别生成新的吡唑并哒嗪衍生物 11、12 和 14。所有新合成化合物的化学结构均根据光谱数据得到确认，并已筛选出抗微生物和抗氧化活性。图形概要