An Efficient Method for Synthesis of N-tert-Butyl Amides Using Oxalic Acid Dihydrate in Solvent-Free Condition

Masoud Mokhtary,Seyedeh Khadijeh Nasernezhad

doi:10.1155/2014/617153

Abstract

An efficient method for the synthesis of N-tert-butyl amides by reaction of nitriles with tert-butyl acetate or tert-butanol is described using oxalic acid dihydrate in solvent-free condition. The result showed that tert-butyl acetate served as a relatively better source of tert-butyl carbocation than tert-butanol.

Highlights

Solvent-free reactions obviously reduce pollution and bring down handling costs due to simplification of experimental procedure, work-up technique, and saving energy
The NMR spectra were recorded in CDCl3 with TMS as an internal standard on a Bruker advance DRX 400 MHz spectrometer
Products were identified by comparison of the obtained FT-IR and 1H NMR spectra with those reported for authentic samples

Summary

Introduction

Solvent-free reactions obviously reduce pollution and bring down handling costs due to simplification of experimental procedure, work-up technique, and saving energy. Ritter reaction using tert-butyl acetate instead of alcohol was reported to be catalyzed by sulfuric acid [14, 15], FeCl3⋅6H2O [16], ZnCl2-SiO2 [17], and I2 [18] Most of these methods suffer from at least one of the following disadvantages such as vigorous reaction conditions, high cost and toxicity of the reagent, tedious work-up procedures, and instability and hygroscopic nature of the reagent. In connection of our research to develop application of oxalic acid dihydrate for oxygenation of sulfides to sufoxides in the presence of H2O2 [23], we found thatoxalic acid dihydrate can be used for preparation of N-tert-butyl amide derivatives in good yields This method often leads to the development of simple and ecofriendly protocols for preparation of Ntert-butyl amides via modified Ritter reaction.

Materials and Measurements

Experimental

Characterization Data

Results and Discussion

Conclusions