Studies on 1,3-benzoxazines. III. Reaction of imidoyl chlorides of 1,3-benzoxazines with 2-hydroxy- or 2-mercaptopyridine N-oxides: A novel S-N bond formation via electrocyclic rearrangement.
作者:RYUJI TACHIKAWA、KAZUYUKI WACHI、SADAO SATO、ATSUSUKE TERADA
DOI:10.1248/cpb.29.3529
日期:——
A novel S-N bond formation through 3, 3-sigmatropic rearrangement in the reaction of imidoyl chlorides of 1, 3-benzoxazines (1) with 2-mercaptopyridine N-oxide (8) is described. Treatment of the imidoyl chlorides (1a-f) with 2-hydroxypyridine N-oxide (2) afforded the corresponding pyridone derivatives (3a-f). When 2-mercaptopyridine N-oxide (8) was used instead of 2, the thiopyridones (7) or N-oxides (9) were obtained and both compounds were transformed to 3-(2-pyridylthio)-4-oxo-2, 3-dihydro-1, 3-benzoxazines (13) through electrocyclic rearrangement on heating in a suitable solvent.
描述了一种通过3,3-信号迁移重排形成S-N键的新方法,该反应涉及1,3-苯并噁嗪的亚氨基氯化物(1)与2-巯基吡啶N-氧化物(8)的反应。用2-羟基吡啶N-氧化物(2)处理亚氨基氯化物(1a-f)得到了相应的吡啶酮衍生物(3a-f)。当用2-巯基吡啶N-氧化物(8)替代2时,得到了硫吡啶酮(7)或N-氧化物(9),这两种化合物通过在适当溶剂中加热进行电环重排转化为3-(2-吡啶基硫)-4-氧-2,3-二氢-1,3-苯并噁嗪(13)。