Cyclization of (2-hydroxyethyl)urea derivatives to give 3-nitroso-2-oxazolidinones under usual nitrosation conditions.
作者:MAKOTO MIYAHARA、MASAHIRO NAKADATE、SHOZO KAMIYA
DOI:10.1248/cpb.33.497
日期:——
Treatment of (2-hydroxyethyl) urea derivatives (Ia-e) with sodium nitrite in the presence of acids or with nitrosyl chloride in chloroform gave 3-nitroso-2-oxazolidinones (IIa-e) in 10-77% yields. These 3-nitroso-2-oxazolidinones were denitrosated with hydrogen chloride in methanol to give the corresponding 2-oxazolidinones (IIIa-e) in 35-60% yields. An N, N-disubstituted urea, 1-(2-hydroxyethyl)-1-methylurea (If) also cyclized to give 3-methyl-2-oxazolidinone (IIf) under the same conditions. The mechanism of this type of cyclization is discussed.
(2-羟乙基)脲衍生物(Ia-e)在酸的存在下与亚硝酸钠反应,或在氯仿中与亚硝基氯反应,得到了3-亚硝基-2-噁唑烷酮(IIa-e),产率为10-77%。这些3-亚硝基-2-噁唑烷酮在甲醇中与氯化氢脱亚硝,得到相应的2-噁唑烷酮(IIIa-e),产率为35-60%。一种N,N-二取代脲,即1-(2-羟乙基)-1-甲基脲(If)在相同条件下也环化,生成3-甲基-2-噁唑烷酮(IIf)。文中讨论了这种环化反应的机制。