57 results about "Curtius rearrangement" patented technology

A preparation method of 2, 3, 4, 9-tetrahydro-beta-carboline-1-one comprises: chloridizing indole-3-propionic acid (III) with a chloridizing agent in an aprotic solvent to prepare indole-3- propionyl chloride (IV), or carrying out condensation reaction between indole-3-propionic acid (III) and chloro-formate in an aprotic solvent under catalysis of an acid binding agent to prepare an active mixed acid anhydride (V); then carrying out an azidation reaction with an azidation reagent to prepare indolepropionyl azide (VI); carrying out a Curtius rearrangement reaction to prepare indoleethyl isocyanate(VII); and finally preparing 2, 3, 4, 9-tetrahydro-beta-carbolin-1-one through a cyclization reaction under catalysis of an acid catalyst. The method is mild in reaction conditions, simple to operate, less in pollution, cheap and accessible in raw materials, simple in technology, high in yield, and ingenious in technology design; and the azidation reaction, Curtius rearrangement and the cyclization are carried out by one-pot synthesis; and in the reaction process, there are not complex operations such as column chromatography, repeated recrystallization and the like, and the technology scaling-up is easy to operate.