57 results about "Curtius rearrangement" patented technology

The invention provides a method for synthesizing 2-(1-imidazol)ethylamine, which uses imidazole and ethyl acrylate as raw material, and includes steps of preparing intermediate (1) ethyl 2-(1-imidazol)propionate from the raw material through Michel addition reaction; preparing intermediate (2) 2-(1-imidazol)propionohydrazide from the intermediate (1) through hydrazinolysis reaction; and obtainingthe object product 2-(1-imidazol)ethylamine from the intermediate (2) through Curtius rearrangement reaction. The invention has total yield of 72% by imidazole, stable reaction, mild condition, and convenient operation and control.

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.

The invention prepares amine compounds based on novel catalytic Curtius rearrangement reaction. Transition metal catalyzed sp 2 C‑N bond formation is an efficient method for the synthesis of arylamines, catalyzing sp 3 The coupling reaction of C-N bond is also reported from time to time, but at the same time, sp 2 and sp 3 Methods for C‑N bond generation are relatively underdeveloped. The present invention uses resource-rich organic carboxylic acids as carbon sources and easily prepared alkane / aryloxyacyl azides as nitrogen sources, at as low as 0.1 mol% of DMAP and Cu(OAc) 2 Under catalysis, with gas N 2 and CO 2 One-pot generation of protected alkyl, alkenyl, and aryl amines as the only by-product. The reaction can be applied to the late functionalization of natural products and drug molecules, the synthesis of chiral alkylamines, and the rapid construction of different ureas and primary amines. Mechanistic studies reveal that the reaction proceeds through a cascade of carboxylic acid activation, azidation, Curtius rearrangement, and nucleophilic addition.