Microwave assisted synthesis and structure–activity relationship of 4-hydroxy-N′-[1-phenylethylidene]-2H/2-methyl-1,2-benzothiazine-3-carbohydrazide 1,1-dioxides as anti-microbial agents

详细信息    查看全文

• 作者：Naveed Ahmad ; Muhammad Zia-ur-Rehman ; Hamid Latif Siddiqui ; Muhammad Fasih Ullah ; Masood Parvez
• 关键词：1 ; 2-Benzothiazine 1 ; 1-dioxide ; Benzothiazine carbohydrazides ; Microwaves assisted synthesis ; 1 ; 4-Dihydropyrazolo[4 ; 3-c][1 ; 2]benzothiazin-3-ol 5 ; 5-dioxide ; Sodium saccharin
• 刊名：European Journal of Medicinal Chemistry
• 出版年：2011
• 出版时间：June 2011
• 年：2011
• 卷：46
• 期：6
• 页码：2368-2377
• 全文大小：388 K

文摘

A series of 4-hydroxy-N′-[1-phenylethylidene]-2H/2-methyl, 1,2-benzothiazine-3-carbohydrazide 1,1-dioxides was synthesized from commercially available sodium saccharin. Base catalyzed ring expansion of methyl (1,1-dioxido-3-oxo-1,2-benzisothiazol-2(3H)-yl)acetate followed by ultrasound mediated hydrazinolysis and subsequent reaction with 1-phenylethanones under the influence of microwaves yielded the title compounds. Besides, microwave assisted synthesis of 1,4-dihydropyrazolo[4,3-c][1,2]benzothiazin-3-ol 5,5-dioxide and 4-methyl-1,4-dihydropyrazolo[4,3-c][1,2]benzothiazin-3-ol 5,5-dioxide is also discussed. Most of the synthesized compounds were found to possess moderate to significant anti-microbial (anti-bacterial and anti-fungal) activities. It is found that compounds with greater lipophilicity (N-methyl analogues) possessed higher anti-bacterial activities.