An efficient method for the N-debenzylation of aromatic heterocycles
摘要:
The treatment of N-benzylated heterocycles with potassium tert-butoxide/DMSO and oxygen at room temperature cleanly affords N-debenzylated products in high yield. This procedure can be utilized on a variety of functionalized nitrogen-containing heterocycles such as imidazoles, benzimidazoles, pyrazoles, indazoles, carbazoles, and indoles. (C) 2002 Published by Elsevier Science Ltd.
Rearrangement of N-(alkylamino)azoles in acid media: a new entry to C-amino-N-substituted azoles
作者:Loreto Salazar、Modesta Espada、Carmen Avendano、Rosa Maria Claramunt、Dionisia Sanz、Jose Elguero
DOI:10.1021/jo00031a042
日期:1992.2
A ring-opening/ring-closure mechanism for the thermal rearrangement of 1-(alkylamino)pyrazoles into 5-amino-1-alkylpyrazoles in acid medium has been established. 1-(Benzylamino)pyrazoles show a different reactivity, affording bis(5-amino-1-benzyl-4-pyrazolyl)phenylmethanes. The reaction was extended to 1-(alkylamino)indazoles but failed in the case of 1-(alkylamino)-1,2,4-triazoles.
An efficient method for the N-debenzylation of aromatic heterocycles
作者:Aubrey A. Haddach、Audrey Kelleman、Melissa V. Deaton-Rewolinski
DOI:10.1016/s0040-4039(01)02192-x
日期:2002.1
The treatment of N-benzylated heterocycles with potassium tert-butoxide/DMSO and oxygen at room temperature cleanly affords N-debenzylated products in high yield. This procedure can be utilized on a variety of functionalized nitrogen-containing heterocycles such as imidazoles, benzimidazoles, pyrazoles, indazoles, carbazoles, and indoles. (C) 2002 Published by Elsevier Science Ltd.
A mild halogenation of pyrazoles using sodium halide salts and Oxone
作者:Kathryn L. Olsen、Matthew R. Jensen、James A. MacKay
DOI:10.1016/j.tetlet.2017.09.042
日期:2017.10
A mild, inexpensive, and operationally simple pyrazole halogenation method utilizing Oxone and sodium halide salts is reported. This work documents 17 examples of alkyl, aryl, allyl, and benzyl substituted 4-chloro and 4-bromopyrazoles, obtained in up to 93% yield. Reactions are performed in water under ambient conditions and generation of organic byproducts is avoided.