91904-57-3

An effective approach for amino protection and construction of a seven-membered ring has been developed. The method uses imidazolium chloride to carry out the Michael addition reaction at low temperatures and perform amino deprotection or construction of a seven-membered ring at high temperatures.

The invention provides an amino protection method which realizes multi-substituted amino protection by using imidazole hydrochloric acid as an accelerator to push derivatives of primary amine, secondary amine and acrylamide to perform Michael addition at a relatively low temperature, wherein the imidazole hydrochloric acid promotes a carbon-nitrogen bond to crack back to the derivatives of primaryamine and acrylamide at a high temperature. The method provided by the invention is simple and economical, high in practicability, free of any other catalysts or additives, capable of protecting amino to have good functional group tolerance and excellent yield and purity, short in reaction time, free from harsh reaction conditions and suitable for industrial production.

A novel method to synthesize β-amino amide has been developed via conjugated addition of amine to bulky α,β-unsaturated amides promoted by silica gel. The silica gel worked efficiently to accelerate the reaction and afforded the related adduct in good to excellent yield.