ORGANIC SULFUR COMPOUNDS: PART I. BENZOTHIAZINE HYDROXAMIC ACIDS AND RELATED COMPOUNDS
作者:R. T. Coutts、H. W. Peel、Elizabeth M. Smith
DOI:10.1139/v65-449
日期:1965.12.1
2H-1,4-Benzothiazine hydroxamic acids of type V (see Table I) are readily prepared by reducing suitably substituted (o-nitrophenylthio)acetates (II, R″ = Me or Et) by means of sodium borohydride and palladium–charcoal. The ester precursors can be prepared by the interaction of o-nitrothiophenols and α-bromoesters, but such a method is limited in scope. Diethyl bromomalonate, for example, reacts atypically
V 型 2H-1,4-苯并噻嗪异羟肟酸(见表 I)可通过硼氢化钠和钯-木炭还原适当取代的(邻硝基苯硫基)乙酸盐(II,R″ = Me 或 Et)来制备。酯前体可以通过邻硝基苯硫酚和α-溴酯的相互作用来制备,但这种方法的范围有限。例如,溴丙二酸二乙酯与邻硝基苯硫酚的反应异常。酯前体通过相应酸的 Fischer-Speier 酯化 (II, R" = H) 更好地制备,而这些酸又是 α-巯基酸对合适的邻氯-(或溴-)硝基苯进行亲核攻击的产物. 这种通用的制备方法在两种情况下都失败了。邻氯硝基苯或4-氯-3-硝基甲苯与α-巯基异丁酸反应时,