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Updated: Feb 28, 2026

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
A simple and facile synthesis of tricyclic-fused pyrimido[4,5-b]indol-2-amines
Wentao Gao1, Dongfang Wang1, Yang Li2
1Institute of Superfine Chemicals, Bohai University, Keji Street, Jinzhou, 121000, People's Republic of China.
Abstract:
In the present investigation, a simple and facile synthetic strategy for the construction of a series of structurally interesting tricyclic-fused N-alkyl-9H-pyrimido[4,5-b]indol-2-amines has been successfully achieved. Our synthesis, based on the annulation reaction between readily available 2-chloroindole-3-carbaldehydes or 3-acetyl-2-chloroindoles and guanidine nitrate using KOH as the base in refluxing EtOH medium, has the attractive features such as mild and economical reaction conditions and easy handing with lesser impact on the environment.
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