The syntheses of tert-alkyl nitroso compounds RCH2CMe2N=O from commercially available tert-alkyl amines RCH2CMe2NH2 proceed cleanly via the intermediacy of the benzoyl derivatives RCH2CMe2NHOC(O)Ph and the corresponding hydroxylamines RCH2CMe2NHOH. Since the intermediates require no purification in the course of the transformations, the overall yields of the isolated crystalline nitroso dimers (75-80% for R = H, 75% for R = Me and 66% for R = Me3C) are based on the corresponding amine precursors. In the latter case (R = Me3C), significant steric demands and hydrophobicity of Me3CCH2CMe2 group necessitate the application of more efficient reagents and conditions on the debenzoylation and oxidation steps. The syntheses are perfectly suitable for scale-up and were successfully performed on up to 500-mmol scale.
从市售的叔烷基胺 RCH2CMe2NH2 合成叔烷基亚
硝基化合物 RCH2CMe2N=O 的过程,通过
苯甲酰基衍
生物 RCH2CMe2NHOC(O)Ph 和相应的羟基胺 RCH2CMe2NHOH 的中间产物进行,过程干净利落。由于这些
中间体在转化过程中无需纯化,因此分离出的亚硝基二聚体结晶的总产率(R = H 为 75-80%,R = Me 为 75%,R = Me3C 为 66%)是以相应的胺前体为
基础的。在后一种情况下(R = Me3C),由于 Me3CCH2CMe2 基团具有明显的立体性和疏
水性,因此需要在去
苯甲酰化和
氧化步骤中使用更有效的试剂和条件。这些合成非常适合放大,并已成功进行到 500 毫摩尔的规模。