Azole derivatives of 1,4-benzothiazine as antifungal agents

New Routes for the Synthesis Novel Heterocyclic via Formation of C-N Bond and via Cleavage a Thiazine Ring of Benzothiazine

“…We have reports here the behavior of both 2-amino thiophenol1and 1-(3-methyl-4H-benzo[b] [1,4]thiazin-2 -yl) ethanone 2toward carbon and nitrogen nucleophiles in the synthesis of pyridine, pyrazole, pyrazolopyridine derivatives. The importance and the utility of 1,4-benzothiazine (1,4-BT) derivatives have led to the development of a wide variety of methods for the preparation of 1,4-benzothiazines have been reported [9].…”

“…Therefore, treatment of compound 1 with enaminone 5 in the refluxing ethanol afforded the red crystal 6 in excellent yield and identified as 4H-benzo[b] [1,4]thiazin-2-yl) (thiophen-2-yl) methanone (6). The structure of 6 was confirmed on the basis of elemental analysis and spectral data (cf.…”

“…When the reaction is carried according to this method and under the same reaction conditions reported in Literature [10], the 1-(3-methyl-4H-benzo[b] [1,4]thiazin-2-yl)ethanone 2 is not isolated. In our hand, we isolate 1-( 2-methyl -2,3 -dihydrobenzo [d] thiazol -2-yl) propan -2-one 3 from the reaction of 1 with acetyl acetone in refluxing ethanol in an excellent yield.…”

“…Benzothiazines are considered to be suitable candidates for different pharmacological activities, such as anticancer [1] antiproliferative agents [2], antimicrobial [3], antifungal activity [4].In some cases 1,4-benzothiazines are also known for their utility as dyes, photographic developers, ultraviolet absorbers light and antioxidants [5]. In continuation of our interest in the synthesis of functionally substituted heterocyclic compounds [6][7][8], we report here the behavior of 2-acetyl-3-methyl-4H-benzo[b] [1,4]thiazine toward carbon and nitrogen nucleophiles in the synthesis of pyrazole, pyridine and pyrazolopyridine derivatives.…”

“…In continuation of our interest in the synthesis of functionally substituted heterocyclic compounds [6][7][8], we report here the behavior of 2-acetyl-3-methyl-4H-benzo[b] [1,4]thiazine toward carbon and nitrogen nucleophiles in the synthesis of pyrazole, pyridine and pyrazolopyridine derivatives.…”