4-Halopyridine 1-Oxide, 4-Haloquinoline 1-Oxideの求核置換反応に関する知見

抄録

Heating of 2 moles of 4-chloropyridine 1-oxide or 4-bromoquinoline 1-oxide and 1 mole of sodium disulfide in aqueous solution results in formation of 4, 4′-thiodipyridine or 4, 4′-thiodiquinoline 1-oxide in 90% yield. Reaction of 1 mole each of the oxide and sodium disulfide gives 4-mercapto-pyridine or -quinoline 1-oxide in 90% yield, while the reaction with 1 mole of sodium thiosulfate affords 4, 4′-thiodipyridine or 4, 4′-thiodiquinoline 1-oxide in 80% yield.
Heating of 4-bromopyridine 1-oxide with potassium thiocyanate in ethanol does not result in the formation of a 4-thiocyanato compound but the same reaction with 3-nitro- or 3-bromopyridine 1-oxide gives 4-thiocyanato compound in 70% yield. 4-Bromoquinoline 1-oxide also undergoes this reaction to give 4-thiocyanatoquinoline 1-oxide in 81% yield. This 4-thiocyanato compound reacts with 2N sodium hydroxide or sodium carbonate when warmed and forms 4, 4′-thiodiquinoline 1, 1′-dioxide, which when warmed with sodium sulfide or reacted with 2N sodium hydroxide at room temperature forms 4-mercaptoquinoline 1-oxide. 4-Bromoquinoline 1-oxide reacts with potassium selenocyanide to form 4-selenocyanatoquinoline 1-oxide in 83.5% yield.