N-Boc-O-对甲苯磺酰羟胺在温和条件下将氨基转变为肼

末端Boc保护的取代肼是氮杂多肽及N-取代吡唑合成中的重要中间体。尽管已有较多方法可以实现，但大多要么涉及复杂的后处理，要么用于芳香取代产物时产率非常低。用N-(叔丁氧基羰基)-O-对甲苯磺酰基羟胺  (CAS No.105838-14-0)与胺反应，可以在非常温和的条件下，获得理想的产物和产率。

 

由芳香胺制备肼试验流程：(以对甲氧基苯胺为例)

To a stirred solution of 4-methoxyaniline (1 g, 8.13 mmol) in DMF (10 ml) was added K2CO3 (1.46 g, 10.57 mmol), and the reaction mixture was cooled to ca. 10 °C. To this was added BocNHOTs (2.8 g, 9.76 mmol) and stirred at r.t. for 2 h. Reaction mixture was diluted with H2O, and the resulting solid was filtered and dried under suction. The dried solid was crystallized from 3% EtOAc in PE to afford the pure product as brown solid.

由脂肪胺制备肼试验流程：(以吗啡啉为例)

To a stirred solution of morpholine (0.5 g, 5.74 mmol) in CH2Cl2 (10 mL) was added NMM (0.75 g, 7.46 mmol), and the reaction mixture was cooled to ca. 10 °C and then added BocNHOTs (1.98 g, 6.90 mmol), and the reaction mixture was stirred at r.t. for 18 h. Reaction mixture was diluted with H2O and extracted with CH2Cl2 (2 × 10 mL). The combined organic layer was dried over Na2SO4 and concentrated. The crude obtained was purified by flash column chromatography to get the pure product as yellow liquid. 

 

Synlett 2011, No. 14, 1993–1996