One-Pot Synthesis of 2,3-Disubstituted Pyrimido[1,2-b]indazole Skeletons from 3-Aminoindazole and Two Distinct Amino
Yingying Zheng1, Xiaotian Wu1,2, Xueyan Lv1
1Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
Abstract:
An effective synthesis for 2,3-disubstituted pyrimido[1,2-b]indazole from 3-aminoindazole and two amino acids was developed. This strategy has been demonstrated with a variety of 3-aminoindazole and amino acids, and it has been successfully scaled up to gram-scale synthesis, highlighting the practicality and application value of the protocol. Furthermore, the utilization of amino acids not only reduces the formation of byproducts but also renders the reaction more environmentally friendly. Mechanistic studies revealed that I2 promoted the decarboxylation of amino acids and the subsequent oxidative cyclization process.
Related Concept Videos
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Preparation of 1° Amines: Gabriel Synthesis
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Structure of Amines
Basicity of Heterocyclic Aromatic Amines
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Mechanism


