Acetylation and acetoxylation of 4-hydroxy-1,4-benzothiazin- and -benzoxazin-3(4H)-ones (cyclic hydroxamic acids)
作者:R. T. Coutts、N. J. Pound
DOI:10.1039/j39710002696
日期:——
with either acetyl chloride or acetic anhydride. Whereas the 4-acetoxy-lactam (IIIb) was formed by the action of acetyl chloride on 4-hydroxy-2H-1,4-benzoxazin-3(4H)-one (IIIa), treatment of this hydroxamic acid with acetic anhydride gave a mixture of the corresponding 6- and 7-acetoxy-lactams (IIIc and e). Mechanisms for the formation of these acetoxy-compounds are suggested, and some of their reactions
用乙酰氯处理4-羟基-2 H -1,4-苯并噻嗪-3(4 H)-一(Ia)及其6-甲基衍生物(Ie),得到4-乙酰氧基衍生物(Ib和f)。然而,当乙酸酐为乙酰化剂时,获得了2-乙酰氧基-内酰胺(Ic和g)。相反,当将对应于(Ia)的砜与乙酰氯或乙酸一起加热时,仅分离出4-乙酰氧基-2 H -1,4-苯并噻嗪-3(4 H)-1,1-二氧化物(IIb)。酐。而4-乙酰氧基-内酰胺(IIIb)是通过乙酰氯在4-羟基-2 H -1,4-苯并恶嗪-3(4 H)-(IIIa),用乙酸酐处理该异羟肟酸,得到相应的6-和7-乙酰氧基-内酰胺(IIIc和e)的混合物。提出了形成这些乙酰氧基化合物的机理,并描述了它们的一些反应。