Efficient Preparation of Biologically Important 1,2-Amino Alcohols

Abstract

An efficient three-step methodology developed for the preparation of 1,2-amino alcohols. In the first step a rapid coupling between bromoketones and potassium phthalimide in ionic liquid produced α-phthalimido ketones in quantitative yields, which is followed by a facile reduction using NaCNBH₃ in acetic acid to give corresponding phthalimido alcohols and finally effecting hydrazinolysis in water at 60 °C to yield biologically important 1,2-amino alcohols.

GRAPHICAL ABSTRACT

Keywords:

• β-Amino alcohols
• hydrazinolysis
• ionic liquid
• NaCNBH₃
• α-phthalimidoketones

ACKNOWLEDGMENT

One of the authors (A. R.) is thankful to the Council of Scientific and Industrial Research, New Delhi, India, for the award of a junior research fellowship.

Notes

Notes. Phth, phthalimide; T (min), time in minutes; Y (%), isolated yield in %.

Notes. Phth, phthalimide; T (h), time in hours; Y (%), isolated yield in %; ND, not detected. The structures of the products were established from their spectral (¹H, ¹³C NMR, and MS) and analytical data.

^a anti/syn = > 99 (using NMR).

^b anti/syn = 43:57.

^c anti/syn = 1:1.

2-eq. of hydrazine hydrate was used and yield mentioned was isolated yield; structures of the final products were confirmed by spectroscopic analysis.