eggshell was found to be a versatile heterogeneous catalyst for the synthesis of pyrano[3,2-c]quinoline derivatives in good yields. this protocol has the advantages of environmental friendliness, short reaction time, low cost and convenient operation.

Quinoline, which belongs to N-heterocyclic compounds, occurs naturally in the environment and is used in numerous industrial processes. The structures of various chemicals, such as dyes and medicines, are based on this compound. Due to that fact, quinoline and its derivatives are widely distributed in environment and can exert toxic effects on organisms from different trophic levels. The abilit...